# Department of Sport and Health Sciences

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## Recent PublicationsView all

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##### Article: Pyruvate Supplementation for Weight Loss: A Systematic Review and Meta-Analysis of Randomized Clinical Trials
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ABSTRACT: Background: Several slimming aids being sold as food supplements are widely available. One of them is pyruvate. Its efficacy in causing weight reduction in humans has not been fully established. The objective of this systematic review was to examine the efficacy of pyruvate in reducing body weight. Methods: Electronic and nonelectronic searches were conducted to identify all relevant human randomized clinical trials. The bibliographies of all located articles were also searched. No restrictions in language or time were applied. Two independent reviewers extracted the data according to predefined criteria. A fixed-effect model was used to calculate mean differences (MD) and 95% confidence interval (CI). Results: Nine trials were identified and 6 were included. All had methodological weaknesses. The meta-analysis revealed a statistically significant difference in body weight with pyruvate compared to placebo (MD: -0.72 kg; 95% CI: -1.24 to -0.20). The magnitude of the effect is small, and its clinical relevance is uncertain. Adverse events included gas, bloating, diarrhea, and increase in low-density lipoprotein (LDL) cholesterol. Conclusion: The evidence from randomized clinical trials does not convincingly show that pyruvate is efficacious in reducing body weight. Limited evidence exists about the safety of pyruvate. Future trials involving the use of this supplement should be more rigorous and better reported.
Critical reviews in food science and nutrition 01/2014; 54(1):17-23. DOI:10.1080/10408398.2011.565890
• ##### Article: Hydrogen sulfide and nitric oxide interactions in inflammation
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ABSTRACT: Together with carbon monoxide (CO), nitric oxide (̇NO) and hydrogen sulfide (H2S) form a group of physiologically important gaseous transmitters, sometimes referred to as the “gaseous triumvirate”. The three molecules share a wide range of physical and physiological properties: they are small gaseous molecules, able to freely penetrate cellular membranes; they are all produced endogenously in the body and they seem to exert similar biological functions. In the cardiovascular system, for example, they are all vasodilators, promote angiogenesis and protect tissues against damage (e.g. ischemia-reperfusion injury). In addition, they have complex roles in inflammation, with both pro- and anti-inflammatory effects reported. Researchers have focused their efforts in understanding and describing the roles of each of these molecules in different physiological systems, and in the past years attention has also been given to the gases interaction or “cross-talk”. This review will focus on the role of ̇NO and H2S in inflammation and will give an overview of the evidence collected so far suggesting the importance of their cross-talk in inflammatory processes.
• ##### Article: Myofibrillar muscle protein synthesis rates subsequent to a meal in response to increasing doses of whey protein at rest and after resistance exercise. Am J Clin Nutr
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ABSTRACT: The intake of whey, compared with casein and soy protein intakes, stimulates a greater acute response of muscle protein synthesis (MPS) to protein ingestion in rested and exercised muscle. We characterized the dose-response relation of postabsorptive rates of myofibrillar MPS to increasing amounts of whey protein at rest and after exercise in resistance-trained, young men. Volunteers (n = 48) consumed a standardized, high-protein (0.54 g/kg body mass) breakfast. Three hours later, a bout of unilateral exercise (8 × 10 leg presses and leg extensions; 80% one-repetition maximum) was performed. Volunteers ingested 0, 10, 20, or 40 g whey protein isolate immediately (∼10 min) after exercise. Postabsorptive rates of myofibrillar MPS and whole-body rates of phenylalanine oxidation and urea production were measured over a 4-h postdrink period by continuous tracer infusion of labeled [(13)C6] phenylalanine and [(15)N2] urea. Myofibrillar MPS (±SD) increased (P < 0.05) above 0 g whey protein (0.041 ± 0.015%/h) by 49% and 56% with the ingestion of 20 and 40 g whey protein, respectively, whereas no additional stimulation was observed with 10 g whey protein (P > 0.05). Rates of phenylalanine oxidation and urea production increased with the ingestion of 40 g whey protein. A 20-g dose of whey protein is sufficient for the maximal stimulation of postabsorptive rates of myofibrillar MPS in rested and exercised muscle of ∼80-kg resistance-trained, young men. A dose of whey protein >20 g stimulates amino acid oxidation and ureagenesis. This trial was registered at http://www.isrctn.org/ as ISRCTN92528122.
American Journal of Clinical Nutrition 11/2013; 99(1). DOI:10.3945/ajcn.112.055517
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##### Article: Assessing Sedentary Behavior with the GENEActiv
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ABSTRACT: The Sedentary Sphere is a method for the analysis, identification and visual presentation of sedentary behaviours from a wrist-worn triaxial accelerometer. To introduce the concept of the Sedentary Sphere, and to determine the accuracy of posture classification from wrist accelerometer data. Three samples were used: 1) free-living (N=13, aged 20-60y); 2) laboratory-based (N=25, aged 30-65y); 3) hospital in-patients (N=10, aged 60-90y). All participants wore a GENEActiv on their wrist and activPAL on their thigh. The free-living sample wore an additional GENEActiv on the thigh and completed the Multimedia Activity Recall for Children & Adults (MARCA). The laboratory-based sample wore the monitors while seated at a desk for seven hours, punctuated by two minutes of walking every 20 minutes. The free-living and in-patient samples wore the monitors for 24 h. Posture was classified from wrist-worn accelerometry using the Sedentary Sphere concept. Sitting time did not differ between the wrist GENEActiv and the activPAL in the free-living sample and was correlated in the three samples combined (rho=0.9, p<0.001), free-living and in-patient samples (r≃0.8, p<0.01). Mean intra-individual agreement was 85±7%. In the laboratory-based and in-patient samples, sitting time was underestimated by the wrist GENEActiv by 30 minutes and two hours relative to the activPAL, respectively (p<0.05). Posture classification disagreed during reading while standing, cooking standing and brief periods during driving. Posture allocation validity was excellent when the GENEActiv was worn on the thigh, evidenced by near perfect agreement with the activPAL (96±3%). The Sedentary Sphere enables determination of the most likely posture from the wrist-worn GENEActiv. Visualising behaviours on the Sphere displays the pattern of wrist movement and positions within that behaviour.
Medicine and science in sports and exercise 11/2013; 46(6). DOI:10.1249/MSS.0000000000000224
• ##### Article: Thirteen follies and fallacies about alternative medicine

EMBO Reports 11/2013; 14(12). DOI:10.1038/embor.2013.174
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##### Article: Aerobic fitness and physical activity in children
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ABSTRACT: In Volume 1 of Pediatric Exercise Science (PES), a paper by Fenster et al. (25) investigated the relationship between peak oxygen uptake (peak V̇O2) and physical activity (PA) in 6- to 8-year-old children. They used both questionnaires and large-scale integrated activity monitors (LSIs) to estimate daily PA and determined peak V̇O2 using an incremental treadmill test to volitional exhaustion. They concluded that peak V̇O2 correlated well with PA as measured by LSIs but commented that questionnaire data were only weakly and nonsignificantly associated with LSI and peak V̇O2 data. Peak V̇O2 and PA are the most researched and reported variables in the 25-year history of PES. Yet, the assessment and interpretation of young people's aerobic fitness and PA remain problematic and any meaningful relationship between them during childhood and adolescence is shrouded with controversy. The present paper uses Fenster et al.'s (25) report as an indicator of where we were 25 years ago, outlines how far we have advanced since then, and suggests future directions of research in the study of aerobic fitness and PA. In the first volume of PES, Fenster, Freedson, Washburn, and Ellison (25) investigated the relationship between 6- to 8-year-old children's peak oxygen uptake (peak V̇O2) and physical activity (PA). Five boys and 13 girls participated in the study and their data were pooled for analysis. Peak V̇O2 was determined during an incremental treadmill test to voluntary exhaustion and PA was estimated using both questionnaires and large-scale integrated activity monitors (LSIs). On the basis of a significant interclass correlation coefficient of r = .59 between peak V̇O2 and the log of LSI average counts per hour Fenster et al. (25) concluded that "aerobic capacity, as measured by peak V̇O2 correlated well with physical activity as measured by LSI" (p.134). They also commented that questionnaire data were only weakly and nonsignificantly associated with LSI and peak V̇O2 data. Young people's peak V̇O2 and PA are the most researched and reported variables in the 25-year history of PES and yet the assessment and interpretation of peak V̇O2 and PA and any meaningful relationship between them during growth and maturation are still shrouded with controversy. The present paper uses Fenster et al.'s (25) work as an indicator of our understanding of young people's peak V̇O2 and PA in 1989, briefly reviews what we know in 2013, and suggests future directions of research.
Pediatric exercise science 11/2013; 25(4):548-60.
• ##### Article: Relationship between metabolic cost and muscular coactivation across running speeds
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ABSTRACT: Muscular coactivation can help stabilise a joint, but contrasting results in previous gait studies highlight that it is not clear whether this is metabolically beneficial. The aim was to assess the relationship between the metabolic cost of running and muscular coactivation across different running speeds, in addition to assessing the reliability and precision of lower limb muscular coactivation. Eleven female recreational runners visited the laboratory on two separate occasions. On both occasions subjects ran at three speeds (9.1, 11 and 12kmh(-1)) for six minutes each. Oxygen consumption and electromyographic data were simultaneously recorded during the final two minutes of each speed. Temporal coactivations of lower limb muscles during the stance phase were calculated. Five muscles were assessed: rectus femoris, vastus lateralis, biceps femoris, tibialis anterior and gastrocnemius lateralis. Nonparametric correlations revealed at least one significant, positive association between lower limb muscular coactivation and the metabolic cost of running for each speed. The length of tibialis anterior activation and muscular coactivation of the biceps femoris-tibialis anterior and gastrocnemius lateralis-tibialis anterior decreased with speed. These results show that longer coactivations of the proximal (rectus femoris-biceps femoris and vastus lateralis-biceps femoris) and leg extensor (rectus femoris-gastrocnemius lateralis) muscles were related to a greater metabolic cost of running, which could be detrimental to performance. The decrease in coactivation in the flexor and distal muscles at faster speeds occurs due to the shorter duration of tibialis anterior activation as speed increases, yet stability may be maintained.
10/2013; 17(6). DOI:10.1016/j.jsams.2013.09.014
• ##### Article: Beetroot juice supplementation speeds O2 uptake kinetics and improves exercise tolerance during severe-intensity exercise initiated from an elevated baseline.
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ABSTRACT: Severe-intensity exercise initiated from an elevated metabolic rate would be expected to enhance the proportional activation of higher-order (type II) muscle fibers. The purpose of this study was therefore to test the hypothesis that, compared to placebo (PL), NO3--rich beetroot juice (BR) supplementation would speed the phase II vo2 kinetics (τp) and enhance exercise tolerance during severe-intensity exercise initiated from a baseline of moderate-intensity exercise. Nine healthy, physically-active subjects were assigned in a randomized, double-blind, crossover design to receive BR (140 mL/day, containing ~8 mmol of NO3(-)) and PL (140 mL/day, containing ~0.003 mmol of NO3(-)) for 6 days. On days 4, 5 and 6 of the supplementation periods, subjects completed a double-step exercise protocol that included transitions from unloaded-to-moderate intensity exercise (U→M) followed immediately by moderate-to-severe-intensity exercise (M→S). Compared to PL, BR elevated resting plasma nitrite concentration (PL: 65 ± 32 vs. BR: 348 ± 170 nM, P<0.01) and reduced the vo2 τp in M→S (PL: 46 ± 13 vs. BR: 36 ± 10 s, P<0.05) but not U→M (PL: 25 ± 4 vs. BR: 27 ± 6 s, P>0.05). During M→S exercise, the faster vo2 kinetics coincided with faster NIRS-derived muscle [deoxyhemoglobin] kinetics (τ; PL: 20 ± 9 vs. BR: 10 ± 3 s, P<0.05) and a 22% greater time-to-task failure (PL: 521 ± 158 vs. BR: 635 ± 258 s, P<0.05). Dietary supplementation with NO3(-)-rich BR juice speeds vo2 kinetics and enhances exercise tolerance during severe-intensity exercise when initiated from an elevated metabolic rate.
AJP Regulatory Integrative and Comparative Physiology 10/2013; 305(12). DOI:10.1152/ajpregu.00295.2013
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##### Article: Effect of Hypohydration on Peripheral and Corticospinal Excitability and Voluntary Activation
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ABSTRACT: We investigated whether altered peripheral and/or corticospinal excitatory output and voluntary activation are implicated in hypohydration-induced reductions in muscle isometric and isokinetic (90°.s(-1)) strength. Nine male athletes completed two trials (hypohydrated, euhydrated) comprising 90 min cycling at 40°C, with body weight losses replaced in euhydrated trial. Peripheral nerve and transcranial magnetic stimulations were applied during voluntary contractions pre- and 40 min post-exercise to quantify voluntary activation and peripheral (M-wave) and corticospinal (motor evoked potential) evoked responses in m. vastus medialis. Both maximum isometric (-15.3±3.1 vs -5.4±3.5%) and isokinetic eccentric (-24.8±4.6 vs -7.3±7.2%) torque decreased to a greater extent in hypohydrated than euhydrated trials (p<0.05). Half relaxation time of the twitch evoked by peripheral nerve stimulation during maximal contractions increased after exercise in the hypohydrated (21.8±9.3%) but stayed constant in the euhydrated (1.6±10.7%; p = 0.017) condition. M-wave amplitude during maximum voluntary contraction increased after exercise in the heat in hypohydrated (10.7±18.0%) but decreased in euhydrated condition (-17.4±16.9%; p = 0.067). Neither peripheral nor cortical voluntary activation were significantly different between conditions. Motor evoked potential amplitude increased similarly in both conditions (hypohydrated: 25.7±28.5%; euhydrated: 52.9±33.5%) and was accompanied by lengthening of the cortical silent period in euhydrated but not hypohydrated condition (p = 0.019). Different neural strategies seem to be adopted to regulate neural drive in the two conditions, with increases in inhibitory input of either intracortical or corticospinal origin during the euhydrated trial. Such changes were absent in the hypohydrated condition, yet voluntary activation was similar to the euhydrated condition, perhaps due to smaller increases in excitatory drive rather than increased inhibition. Despite this maximal isometric and eccentric strength were impaired in the hypohydrated condition. The increase in peripheral muscle excitability evident in the hypohydrated condition was not sufficient to preserve performance in the face of reduced muscle contractility or impaired excitation-contraction coupling.
PLoS ONE 10/2013; 8(10):e77004. DOI:10.1371/journal.pone.0077004
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ABSTRACT: Molassiotis is the author of about 40 reviews, all of which are prone to the shortcomings he highlights. His statement, “I urge researchers in the field not to proliferate publications of ‘systematic’ reviews of a very small number and of admittedly poor/low quality level trials”, is thus surprising to say the least. The main point of his response seems to be that “systematic reviews of few and low-quality studies do not help anybody”. We feel that such articles can still be useful, for instance, for disclosing important deficits in our current knowledge. In making this point, Molassiotis seems to display a lack of understanding of science in general and systematic reviews in particular. Here are a few of his most obvious errors: He asks “didn’t we know this [the result of a systematic review] before the review”? It seems obvious to us that the findings of a review can never be known before the research has been conducted. He refers to “systematic reviews on the same topic by several different authors”. Yet a closer look at the actual articles he quotes informs us that they are, in fact, on subtly different subjects. He claims that we believe that “anything that does not have a sham arm is not a good trial”. Yet we never stated anything like this. We would, however, argue that, for determining whether an intervention has therapeutic effects beyond placebo, a placebo/sham control is helpful. He argues that controlling for placebo effects in acupuncture trials is done “to give some ‘science’ credentials to such trials and mimic drug trial placebo-controlled designs”. We would counter that the sole reason for doing this is to be able to differentiate between specific and non-specific therapeutic effects; in our view, this is important for determining the value of any treatment. He states, “I am questioning the ethics” [of such sham controlled studies].We would insist that differentiating between placebo and specific effects is a crucial ethical task of clinical research. He claims that “bringing all acupuncture trials together as one treatment is like mixing apples and oranges”. We would like to remind him that, by definition, systematic reviews are about summary judgements of this nature and that most of his own reviews have followed exactly the same principles. Finally, we agree with him that “we should not deny patients the possibility of experiencing symptom relief and health improvements because of sterile and incapacitating arguments about how to carry out ‘proper’ acupuncture trials”. But we need to point out that, before we can be sure that patients do benefit from our interventions, we need to determine whether they generate more good than harm. In our opinion, this requires rigorous research, and any attempt to bypass this process is likely to be counterproductive and unethical. Conflict of interest Both authors declare no competing interests. Open Access This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.
Supportive Care in Cancer 10/2013; DOI:10.1007/s00520-013-1990-5
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##### Article: Muscle metabolic responses during high-intensity intermittent exercise measured by 31P-MRS: Relationship to the critical power concept
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ABSTRACT: We investigated the responses of intramuscular phosphate-linked metabolites and pH (as assessed by (31)P-MRS) during intermittent high-intensity exercise protocols performed with different recovery-interval durations. Following estimation of the parameters of the power-duration relationship (i.e., CP and W') for severe-intensity constant-power exercise, eight male subjects completed three intermittent exercise protocols to exhaustion where periods of high-intensity exercise (60-s) were separated by different durations of passive recovery (18-s, 30-s and 48-s). The tolerable duration of exercise was 304 ± 68 s, 516 ± 142 s and 847 ± 240 s for the 18-s, 30-s and 48-s recovery protocols, respectively (P<0.05). The work done >CP (W>CP) was significantly greater for all intermittent protocols compared to the subjects' W' and this difference became progressively greater as recovery-interval duration was increased. Similarly, the degree of intramuscular phosphocreatine restoration during recovery was greatest, intermediate and least for 48-s, 30-s and 18-s of recovery, respectively (P<0.05). The W>CP in excess of W' increased with greater durations of recovery and this was correlated with the mean magnitude of muscle phosphocreatine reconstitution between work intervals (r = 0.61; P<0.01). During intermittent high-intensity exercise, recovery intervals allow intramuscular homeostasis to be restored, with the degree of restoration being related to the duration of the recovery interval. Consequently, the ability to perform W>CP during intermittent high-intensity exercise and, therefore, exercise tolerance, increases in a predictable manner when recovery-interval duration is extended.
AJP Regulatory Integrative and Comparative Physiology 09/2013; 305(9). DOI:10.1152/ajpregu.00406.2013
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##### Article: Seasonal variation in physical activity and sedentary time in different European regions. The HELENA study
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ABSTRACT: Abstract This report aims (1) to examine the association between seasonality and physical activity (PA) and sedentary time in European adolescents and (2) to investigate whether this association was influenced by geographical location (Central-North versus South of Europe), which implies more or less extreme weather and daylight hours. Valid data on PA, sedentary time and seasonality were obtained in 2173 adolescents (1175 females; 12.5-17.5 years) included in this study. Physical activity and sedentary time were measured by accelerometers. ANCOVA was conducted to analyse the differences in PA and sedentary time across seasons. Results showed that girls had lower levels of moderate to vigorous PA (MVPA) and average PA, and spent more time in sedentary activities in winter compared with spring (all P < 0.05). Stratified analyses showed differences in PA and sedentary time between winter and spring in European girls from Central-North of Europe (P < 0.05 for sedentary time). There were no differences between PA and sedentary time across seasonality in boys. In conclusion, winter is related with less time spent in MVPA, lower average PA and higher time spent in sedentary activities in European adolescent girls, compared with spring. These differences seem to mainly occur in Central-North Europe.
Journal of Sports Sciences 09/2013; 31(16). DOI:10.1080/02640414.2013.803595
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##### Article: Yo-Yo intermittent recovery test performances within an entire football league during a full season
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ABSTRACT: Abstract The study examined Yo-Yo intermittent recovery level 2 (YYIR2) and submaximal YYIR1 test performances in 172 male semi-professional football players (age; 25.8 ± 4.1 years) representing all teams in a top league at pre-season, start-season, mid-season and end-season. YYIR2 performance was 847 ± 227 m (±SD) at pre-season and rose (P < 0.05) by 128 ± 113 m to 975 ± 205 m at start of season and further (P < 0.05) by 59 ± 102 m to 1034 ± 211 m at mid-season. Submaximal YYIR1 HR was 90.9 ± 4.2% HRmax at pre-season, which was higher (P < 0.05) than at start, mid and end of season (87.0 ± 3.9, 85.9 ± 4.1 and 87.0 ± 3.7% HRmax, respectively). Peak YYIR2 performance and minimum YYIR1 HR were 1068 ± 193 m and 85.1 ± 3.8% HRmax, respectively, with ∼50% of the players peaking at mid-season. Top-teams and middle-teams had higher (P < 0.05) peak YYIR2 scores (1094 ± 205 and 1121 ± 152 m, respectively) than bottom-teams (992 ± 185 m). YYIR2 performance was 16% higher (P < 0.05) and YYIR1 HR was 1.4% HRmax lower (P < 0.05) for regular players than non-regular players at pre-season and remained lower (P < 0.05) throughout the season. Central defenders had poorer (P < 0.05) YYIR performances compared to other positional roles. In conclusion, YYIR performances are highly variable within a football league over a season and are influenced by league ranking, regularity of competitive play and playing position.
Journal of Sports Sciences 08/2013; 32(4). DOI:10.1080/02640414.2013.824598
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##### Article: Biomechanical characteristics of barefoot footstrike modalities
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ABSTRACT: Barefoot running has increased in popularity over recent years, with suggested injury risk and performance benefits. However, despite many anecdotal descriptions of barefoot running styles, there is insufficient evidence regarding the specific characteristics of barefoot running. The present study provided reference data for four footstrike modalities adopted across a large cohort of habitually shod male runners while running barefoot: heel strikers (HS), midfoot strikers (MS), forefoot strikers (FS) and a newly defined group, toe runners (TR - contact made only with the forefoot), compared with the three modalities previously reported. Plantar pressure analysis was used for the classification of footstrike modality, with clearly distinguishable pressure patterns for different modalities. In the present study, the distribution of footstrike types was similar to that previously observed in shod populations. The absence of differences in ground contact time and stride length suggest that potential performance benefits of a non-HS style are more likely to be a function of the act of running barefoot, rather than of footstrike type. Kinematic data for the knee and ankle indicate that FS and TR require a stiffer leg than HS or MS, while ankle moment and plantar pressure data suggest that a TR style may put greater strain on the plantar-flexors, Achilles tendon and metatarsal heads. TR style should therefore only be adopted with caution by recreational runners. These findings indicate the importance of considering footstrike modality in research investigating barefoot running, and support the use of four footstrike modalities to categorise running styles.
Journal of Biomechanics 08/2013; 46(15). DOI:10.1016/j.jbiomech.2013.08.009
• ##### Article: A brisk walk, compared with being sedentary, reduces attentional bias and chocolate cravings among regular chocolate eaters with different body mass
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ABSTRACT: Poor self-regulation of high energy snacking has been linked to weight gain. Physical activity can acutely reduce chocolate consumption and cravings but the effects on attentional bias (AB) are unknown. The study aimed to test the effects of exercise among normal and overweight/obese individuals during temporary and longer abstinence. Participants were 20 normal and 21 overweight regular female chocolate eaters (after 24 hr abstinence), and 17 females (after ⩾ 1 week abstinence during Lent). They were randomly assigned to engage in 15 min brisk walking or rest, on separate days. AB was assessed using an adapted dot probe task pre and post-treatment at each session, with chocolate/neutral paired images presented for 200ms (initial AB; IAB) or 1000ms (maintained AB; MAB). Chocolate craving was assessed pre, during, immediately after, and 5mins and 10mins after treatment, using a 0-100 visual analogue score. Three-way mixed ANOVAs revealed that there was no significant interaction effect between group (i.e., BMI status, or abstinence status) and condition × time for craving and AB to chocolate cues. Fully repeated 2-way ANOVAS revealed a significant condition × time interaction for IAB (F(1, 57) = 6.39) and chocolate craving (F(2.34, 133.19) = 14.44). After exercise IAB (t(57) = 2.78, p< 0.01) was significantly lower than after the rest condition. Craving was significantly lower than the rest condition at all assessments post-baseline. A short bout of physical activity reduces cravings and AB to chocolate cues, relative to control, irrespective of BMI or abstinence period.
Appetite 08/2013; 71. DOI:10.1016/j.appet.2013.07.015
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##### Article: Influence of surgery and rehabilitation conditioning on psychophysiological fitness
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ABSTRACT: The purpose of this study was to assess changes in psychophysiological fitness following reconstructive knee surgery and early phase (2.5 months) physical rehabilitation. Nine patients (7 male, 2 female; mean age, 29.9 years) electing to undergo anterior cruciate ligament reconstructive surgery (central third, bone-patella tendon-bone graft) were assessed on four separate assessment occasions post-surgery. Repeated measures ANOVAs showed significant condition (injured/non-injured leg) by test occasion (2 weeks pre-surgery and 6, 8 and 10 weeks post-surgery) interactions for knee ligamentous compliance (anterior tibiofemoral displace-ment), peak force and electromechanical delay associated with the knee flexors of the injured and non-injured legs (F 3,24 = 4.7 to 6.6; p < 0.01), together with individualized emotional profile disturbance scores that were significantly less at 10 weeks post-surgery compared to pre-surgery, 6 weeks and 8 weeks post-surgery (F 3,24 = 7.6; p < 0.01). Spearman rank correlation coefficients identified significant relationships between musculoskeletal fitness and emotional profile scores at pre-surgery (r = 0.69–0.72; p < 0.05) and at 8 weeks post-surgery (r = 0.70–0.73; p < 0.05). The 6 Bi-POMS subscales and the 12 ERAIQ responses found inconsis-tent patterns of response and relationships across the assessment occasions. Overall, the patterning of changes and associations amongst emotional performance profile discrepancy scores in conjunction with those scores from indices of musculoskeletal fitness performance capability offered important support for the efficacy of an approach which integrates self-perceptive and objective measurements of fitness capability during rehabilitation following surgery to a synovial joint.
Journal of exercise science and fitness (JESF) 07/2013;
• ##### Article: Musculoskeletal health profile for elite female footballers versus untrained young women before and after 16 weeks of football training
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ABSTRACT: Abstract We investigated the musculoskeletal health profile of elite female football players (ET) in comparison to untrained (UT) young women subjected to 16 weeks of football training (2 × 1 h per week). DXA scans, blood sampling, sprint testing and Flamingo postural balance testing were carried out for 27 Danish national team players and 28 untrained women, with eight women being tested after training. At baseline total BMD and BMC were 13% (1.305 ± 0.050 versus 1.159 ± 0.056 g · cm(-2)) and 23% (3047 ± 235 versus 2477 ± 526 g) higher (P <0.001) and leg BMD and BMC were 24 and 28% higher (P <0.01) in ET than in UT. Resting plasma osteocalcin was 45% higher in ET than in UT (28.8 ± 10.9 versus 19.9 ± 9.9 µg · L(-1), P <0.05). Total lean body mass was 14% higher (50.4 ± 3.3 versus 44.3 ± 4.0 kg) in ET compared with UT, with no difference in total body mass. The number of Flamingo test falls was 56-63% less (P <0.01) and 30 m sprinting speed was 31% faster (P <0.001) in ET than UT. After 16 weeks of football training for UT, lean body mass increased by 1.4 ± 0.5 kg and the number of left leg falls decreased by 29% (P <0.05). No significant changes occurred in BMD or BMC, but plasma osteocalcin increased (P <0.05) by 37%. In summary, elite women footballers have an impressive musculoskeletal health profile compared with untrained controls, but short-term football training seems to reduce the risk of falls and increase bone formation.
Journal of Sports Sciences 07/2013; 31(13). DOI:10.1080/02640414.2013.796066
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##### Article: Relationships Between Field Performance Tests in High-Level Soccer Players
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ABSTRACT: In order to reduce athlete testing time, the aim of this study was to investigate the relationship between the Yo-Yo intermittent recovery test level 1 (IR1) and 2 (IR2) test performances, maximal sprinting speed (10, 20 and 35 m), repeated sprint ability (RSA) (7x35 m), and sub-maximal heart rates after two and four minutes of the Yo-Yo IR tests by testing 57 high-level soccer players. All players played regularly in one of the three highest levels of Norwegian soccer and were tested during three sessions on three consecutive days. Large correlations were observed between Yo-Yo IR1 and IR2 test performances (r=0.753 p≤0.05). Small and moderate correlations were found between 20 and 35 m sprinting speed and Yo-Yo IR1 performance (r=-0.289 and -0.321, respectively, p≤0.05), while 35 m sprinting speed correlated moderately to Yo-Yo IR2 performance (r=-0.371, p≤0.05). RSA at 10, 20 and 35 m all showed moderate to large correlations to Yo-Yo IR1 performance (r=-0.337 to -0.573, p≤0.05). RSA at 20 m (r = -0.348, p≤0.05) and 35 m (r=-0.552, p≤0.01) correlated moderately and largely to Yo-Yo IR2 performance. Also, moderate and large correlations were found between sub-maximal Yo-Yo IR1 heart rates after 2 (r=-0.483, p≤0.01) and 4 min (r=-0.655, p≤0.01) and Yo-Yo IR1 performance, and 2 min Yo-Yo IR2 heart rate and Yo-Yo IR2 performance (r=-0.530, p≤0.01). ICC measures of sub-maximal HR after 2 and 4 min of Yo-Yo IR1 test, and after 2 min of the Yo-Yo IR2 were 0.92 (CV=4.1%, n=33), 0.93 (CV=3.8%, n=33) and 0.72 (CV=2.9%, n=10). Adjusted ordinary least square (OLS) regressions revealed associations (p≤0.05) between sprint speed at 20 m and 35 m and Yo-Yo IR1 test performance, but only between 35 m and IR2 test performance (p≤0.05). Further, OLS showed that RSA at 35 m was related to both levels of the Yo-Yo IR test (p≤0.01), and that sub-maximal heart rates after 2 and 4 min were independently associated to Yo-Yo IR1 and IR2 performances (p≤0.01). In conclusion, Yo-Yo IR1 and 2 test performances, as well as sprint and RSA performances, correlated very largely, and it may therefore be considered using only one of the Yo-Yo tests and a RSA test, in a general soccer-specific field test protocol. The sub-maximal heart rate measures during Yo-Yo tests are reproducible and may be utilized for frequent, time-efficient and non-exhaustive testing of intermittent exercise capacity of high-level soccer players.
The Journal of Strength and Conditioning Research 07/2013; 28(4). DOI:10.1519/JSC.0b013e3182a1f861
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##### Article: Critical power derived from a 3-min all-out test predicts 16.1-km road time-trial performance
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ABSTRACT: Abstract It has been shown that the critical power (CP) in cycling estimated using a novel 3-min all-out protocol is reliable and closely matches the CP derived from conventional procedures. The purpose of this study was to assess the predictive validity of the all-out test CP estimate. We hypothesised that the all-out test CP would be significantly correlated with 16.1-km road time-trial (TT) performance and more strongly correlated with performance than the gas exchange threshold (GET), respiratory compensation point (RCP) and [Formula: see text]O2 max. Ten club-level male cyclists (mean±SD: age 33.8±8.2 y, body mass 73.8±4.3 kg, [Formula: see text]O2 max 60±4 ml·kg(-1)·min(-1)) performed a 10-mile road TT, a ramp incremental test to exhaustion, and two 3-min all-out tests, the first of which served as familiarisation. The 16.1-km TT performance (27.1±1.2 min) was significantly correlated with the CP (309±34 W; r=-0.83, P<0.01) and total work done during the all-out test (70.9±6.5 kJ; r=-0.86, P<0.01), the ramp incremental test peak power (433±30 W; r=-0.75, P<0.05) and the RCP (315±29 W; r=-0.68, P<0.05), but not with GET (151±32 W; r=-0.21) or the [Formula: see text]O2 max (4.41±0.25 L·min(-1); r=-0.60). These data provide evidence for the predictive validity and practical performance relevance of the 3-min all-out test. The 3-min all-out test CP may represent a useful addition to the battery of tests employed by applied sport physiologists or coaches to track fitness and predict performance in atheletes.
06/2013; 14(3). DOI:10.1080/17461391.2013.810306
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##### Article: Acute physiological and performance responses to repeated sprints in varying degrees of hypoxia
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ABSTRACT: Our aim was to determine the effects of different inspired oxygen fractions on repeated sprint performance and cardiorespiratory and neuromuscular responses, to construct a hypoxic dose response. Nine male well-trained multi-sport athletes completed 10×6s all-out running sprints with 30s recovery in 5 conditions with different inspired oxygen fraction (FIO2: 12%, 13%, 14%, 15%, 21%). Peak running speed was measured in each sprint and electromyography data were recorded from m. vastus lateralis in parallel with heart rate and blood oxygen saturation. Cardiorespiratory response was assessed via breath by breath expired air analysis and muscle oxygenation status was evaluated via near infrared spectroscopy. In parallel with the higher heart rate, minute ventilation, blood lactate concentration, and muscle deoxygenation; lower blood oxygen saturation, pulmonary oxygen uptake and integrated EMG (all p<0.05) were registered in all hypoxic conditions, with the greatest changes from baseline observed during the 13% trial. However, fatigue index and speed decrement were significantly greater only during the 12% vs 21% trial (p<0.05). Physiological responses associated with performing 10×6s sprints interspersed with 30s passive recovery was incrementally greater as FIO2 decreased to 13%, yet fatigue development was significantly exacerbated relative to normoxia (FIO2: 21%) only at the 12% FIO2.
06/2013; 17(4). DOI:10.1016/j.jsams.2013.05.016
• ##### Article: Influence of Dietary Nitrate Supplementation on Exercise Tolerance and Performance
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ABSTRACT: Several recent studies indicate that supplementation of the diet with inorganic nitrate results in a significant reduction in pulmonary O2 uptake during sub-maximal exercise, an effect that appears to be related to enhanced skeletal muscle efficiency. The physiological mechanisms responsible for this effect are not completely understood but are presumably linked to the bioconversion of ingested nitrate into nitrite and thence to nitric oxide. Nitrite and/or nitric oxide may influence muscle contractile efficiency perhaps via effects on sarcoplasmic reticulum calcium handling or actin-myosin interaction, and may also improve the efficiency of mitochondrial oxidative phosphorylation. A reduced O2 cost of exercise can be observed within 3 h of the consumption of 5-6 mmol of nitrate, and this effect can be preserved for at least 15 days provided that the same 'dose' of nitrate is consumed daily. A reduced O2 cost of exercise following nitrate supplementation has now been reported for several types of exercise including cycling, walking, running, and knee extension exercise. Dietary nitrate supplementation has been reported to extend the time to exhaustion during high-intensity constant work rate exercise by 16-25% and to enhance cycling performance over 4, 10, and 16.1 km by 1-2% in recreationally active and moderately trained subjects. Although nitrate appears to be a promising 'new' ergogenic aid, additional research is required to determine the scope of its effects in different populations and different types of exercise. Copyright © 2013 Nestec Ltd., Vevey/S. Karger AG, Basel.
NestlÃ© Nutrition Institute workshop series 06/2013; 75:27-40. DOI:10.1159/000345815
• ##### Article: Prevalence of complementary and alternative medicine (CAM)-use in UK paediatric patients: A systematic review of surveys
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ABSTRACT: This systematic review is aimed at estimating the prevalence of complementary and alternative medicine (CAM)-use by paediatric populations in the United Kingdom (UK). AMED, CINAHL, COCHRANE, EMBASE and MEDLINE were searched for English language peer-reviewed surveys published between 01 January 2000 and September 2011. Additionally, relevant book chapters and our own departmental files were searched manually. Eleven surveys were included with a total of 17,631 paediatric patients. The majority were of poor methodological quality. Due to significant heterogeneity of the data, a formal meta-analysis was deemed inappropriate. Ten surveys related to CAM in general, while one was specifically on homeopathy. Across all surveys on CAM in general, the average one-year prevalence rate was 34% and the average lifetime prevalence was 42%. In surveys with a sample size of more than 500, the prevalence rates were considerably lower than in surveys with the sample size of lower than 500. Herbal medicine was the most popular CAM modality, followed by homeopathy and aromatherapy. Many paediatric patients in the UK seem to use CAM. Paediatricians should therefore have sufficient knowledge about CAM to issue responsible advice.
Complementary therapies in medicine 06/2013; 21(3):224-31. DOI:10.1016/j.ctim.2012.11.006
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##### Article: Reproducibility of maximal cardiopulmonary exercise testing for young cystic fibrosis patients
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ABSTRACT: Background: The reproducibility of cardiopulmonary exercise testing (CPET) has not been established in young cystic fibrosis (CF) patients using a valid protocol. Methods: Thirteen 7-18 year olds completed three CPETs, separated by 48 h and 4-6 weeks. CPET involved a ramp-incremental cycling test with supramaximal verification. Results: Maximal oxygen uptake was repeatedly determined with no learning effect and typical errors expressed as a coefficient of variation (TE(CV%)) of 9.3% (48 h) and 13.3% (4-6 weeks). The reproducibility of additional parameters of aerobic function [gas exchange threshold (TE(CV%): 11.2%, 16.8%); VO2 mean response time (TE(CV%): 37.8%, 89.4%); VO2 gain (TE(CV%): 17.4%, 24.5%)] and clinical utility [e.g. SaO2% (TE(CV%): 2.2%, 3.1%); ventilatory drive (V(E)/VCO2-slope) (TE(CV%): 7.8%, 17.7%)] was also established over the short- and the medium-term, respectively. Conclusion: These results establish limits of variability to determine meaningful changes over the short- and the medium-term for CPET outcomes in young CF patients.
Journal of cystic fibrosis: official journal of the European Cystic Fibrosis Society 05/2013; 12(6). DOI:10.1016/j.jcf.2013.04.012
• ##### Article: Use of accelerometry to classify activity beneficial to bone in premenopausal women
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ABSTRACT: Purpose: The aims of this study were to quantify the relation between ground reaction force (GRF) and peak acceleration from hip- and wrist-worn accelerometers and determine peak acceleration cut-points associated with a loading rate previously demonstrated as beneficial to bone (43 body weights (BW)·s⁻¹) in premenopausal women. Methods: Forty-seven premenopausal women (age, 39.2 ± 5.6 yr; mass, 65.9 ± 11.0 kg; height, 1.67 ± 0.06 m) performed walking (slow, fast, and with bag), floor sweeping, running (slow and fast), jumping (low, <5 cm; high, >5 cm), and box drop (20 cm) trials. Peak accelerations were sampled at 100 Hz by GENEActiv and ActiGraph GT3X+ accelerometers (ActiGraph LLC, Pensacola, FL) worn at the hip (vertical and resultant) and the wrist (resultant). A force plate (960 Hz, AMTI) was used to assess peak vertical GRF and peak loading rate for eight steps per activity. Receiver operating characteristic curves were used to determine the optimal peak acceleration cut-points associated with a loading rate of 43 BW·s⁻¹ in 37 participants, and these cut-points were cross-validated in the remaining 10 participants. Results: For all activities combined, peak accelerations were positively and significantly (P < 0.001) correlated with peak vertical GRF (hip r > 0.8, wrist r > 0.7) and peak loading rate (hip r > 0.7, wrist r > 0.57). Irrespective of monitor type and wear site, peak acceleration discriminated between loading rates above and below 43 BW·s⁻¹ with high levels of accuracy (area under the curve >0.92, P < 0.001). Overall classification agreement was >85% for both monitors worn at either the wrist or hip in the cross-validation sample. Conclusion: GENEActiv and ActiGraph GT3X+ accelerometers worn at the wrist or hip can be used as an unobtrusive tool to identify the occurrence of loading rates likely beneficial to bone in premenopausal women during their daily activity.
Medicine and science in sports and exercise 05/2013; 45(12). DOI:10.1249/MSS.0b013e31829ba765
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##### Article: Soccer Training Improves Cardiac Function in Men with Type 2 Diabetes
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ABSTRACT: INTRODUCTION: Patients with type 2 diabetes (T2DM) have an increased risk of cardiovascular disease which is worsened by physical inactivity. Subclinical myocardial dysfunction is associated with increased risk of heart failure and impaired prognosis in T2DM; however, it is not clear if exercise training can counteract the early signs of diabetic heart disease. PURPOSE: To evaluate the effects of soccer training on cardiac function, exercise capacity and blood pressure in middle-aged men with T2DM. METHODS: Twenty-one men aged 49.8±1.7 yrs with T2DM and no history of cardiovascular disease, participated in a soccer training group (STG; n=12) that trained one h twice a week or a control group (CG; n=9) with no change in lifestyle. Examinations included comprehensive transthoracic echocardiography, measurements of blood pressure, maximal oxygen consumption (VO2max) and intermittent endurance capacity before and after 12 and 24 wks. Two-way repeated-measures ANOVA was applied. RESULTS: After 24 wks of soccer training, left ventricular (LV) end-diastolic diameter and volume were increased (P<0.001) compared to baseline. LV longitudinal systolic displacement was augmented by 23% (P<0.001) and global longitudinal 2D strain increased by 10% (P<0.05). LV diastolic function, determined by mitral inflow (E/A-ratio) and peak diastolic velocity E´ were increased by 18% (P<0.01) and 29% (P<0.001), respectively while LV filling pressure E/E´ was reduced by 15% (P=0.05). Systolic, diastolic and mean arterial pressures were all reduced by 8 mmHg (P<0.01, P<0.001 and P<0.001, respectively). VO2max and intermittent endurance capacity was 12% and 42% (P<0.001) higher, respectively. No changes in any of the measured parameters were observed in CG. CONCLUSION: Regular soccer training improves cardiac function, increases exercise capacity and lowers blood pressure in men with T2DM.
Medicine and science in sports and exercise 05/2013; 45(12). DOI:10.1249/MSS.0b013e31829ab43c
• ##### Article: Glycaemic index of meals affects appetite sensation but not energy balance in active males
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ABSTRACT: BACKGROUND: Foods with low glycaemic index (LGI) are reported to suppress appetite mainly in overweight population but have not been investigated in athletic adults. OBJECTIVE: The aim of this study was to compare the short-term effects of LGI and high GI (HGI) meals over a day on subsequent subjective appetite sensation, energy intake, energy expenditure, energy balance and resting metabolic rate in physically active males. METHODS: This cross-sectional randomized crossover study included 14 active males (mean ± SD; age 34.5 ± 8.9 years, body mass index 22.8 ± 2.1 kg m(-2)) to consume LGI and HGI meals on two separate days. On each trial day, participants consumed a breakfast in the laboratory and then left with a packed lunch, dinner and snacks. Appetite scores, energy intake and expenditure were assessed. RESULTS: The area under the curve for appetite scores of the HGI trial was significantly smaller than that of the LGI trial during the laboratory period (p = 0.027) and throughout the day (p = 0.009). No significant differences in energy intake, energy expenditure, energy balance and resting metabolic rate were found between groups, between the trial days and between the corresponding post-trial days. CONCLUSIONS: These results show that frequent ingestion of the HGI meals, contrary to the previous reports, suppresses appetite more than that of LGI meals, but did not affect energy balance in physically active normal-weight males.
European Journal of Nutrition 05/2013; 53(1). DOI:10.1007/s00394-013-0529-3
• ##### Article: Beetroot juice and exercise: Pharmacodynamic and dose-responce relationships
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ABSTRACT: Dietary supplementation with beetroot juice (BR) containing ~5-8 mmol of inorganic nitrate (NO3(-)) increases plasma nitrite concentration ([NO2(-)]), reduces blood pressure, and may positively influence the physiological responses to exercise. However, the dose-response relationship between the volume of BR ingested and the physiological effects invoked has not been investigated. In a balanced crossover design, 10 healthy males ingested 70, 140 or 280 ml of concentrated BR (containing 4.2, 8.4 and 16.8 mmol NO3-, respectively) or no supplement to establish the effects of BR on resting plasma [NO3(-)] and [NO2(-)] over 24 h. Subsequently, on six separate occasions, 10 subjects completed moderate-intensity and severe-intensity cycle exercise tests 2.5 h post-ingestion of 70, 140 and 280 ml BR, or NO3(-)-depleted BR as placebo (PL). Following acute BR ingestion, plasma [NO2(-)] increased in a dose-dependent manner, with the peak changes occurring at ~2-3 h. Compared to PL, 70 ml BR did not alter the physiological responses to exercise. However, 140 and 280 ml BR reduced the steady-state VO2 during moderate-intensity exercise by 1.7% (P=0.06) and 3.0% (P<0.05), whilst time to task failure was extended by 14% and 12% (both P<0.05), respectively, compared to PL. The results indicate that, while plasma [NO2(-)] and the O2 cost of moderate-intensity exercise are improved dose-dependently with NO3(-)-rich BR, there is no additional improvement in exercise tolerance after ingesting BR containing 16.8 compared to 8.4 mmol NO3(-). These findings have important implications for the use of BR to enhance cardiovascular health and exercise performance in young adults.
Journal of Applied Physiology 05/2013; 115(3). DOI:10.1152/japplphysiol.00372.2013
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##### Article: Muscle metabolic determinants of exercise tolerance following exhaustion: Relationship to the "critical power
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ABSTRACT: We tested the hypothesis that muscle high-energy phosphate compounds and metabolites related to the fatigue process would be recovered after exhaustion during recovery exercise performed below but not above critical power (CP) and that these changes would influence the capacity to continue exercise. Eight male subjects completed single-leg knee-extension exercise to exhaustion (for ~ 180 s) on three occasions, followed by a work-rate reduction to either severe-intensity exercise (>CP), heavy-intensity exercise (<CP), or a 10 min passive recovery period, in a random order. The muscle metabolic responses to exercise were assessed using (31)P magnetic resonance spectroscopy. There was a significant difference between the sustainable exercise duration during the recovery from exhaustive exercise between the CP conditions (at least 10 min and 39 ± 31 s, respectively; P<0.05). During passive recovery and <CP recovery exercise, muscle phosphocreatine concentration ([PCr]) increased rapidly after the exhaustion point reaching ~ 96 % and ~ 76 % of baseline values, respectively, after 10 min (P<0.05). Moreover, pH increased abruptly, reaching 7.0 ± 0.0 and 7.0 ± 0.2, respectively, after 10 min recovery (P<0.05). However, during >CP recovery exercise, neither muscle [PCr] nor pH recovered, reaching ~37 % of the initial baseline and 6.6 ± 0.2, respectively. These results indicate that the muscle metabolic dynamics in recovery from exhaustive severe-intensity exercise differ according to whether the recovery exercise is performed below or above the CP. These findings confirm the importance of the CP as an intramuscular metabolic threshold which dictates the accumulation of fatigue-related metabolites and the capacity to tolerate high-intensity exercise.
Journal of Applied Physiology 05/2013; 115(2). DOI:10.1152/japplphysiol.00334.2013
• ##### Article: The relationship between sagittal curvature and extensor muscle volume in the lumbar spine
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ABSTRACT: A previous modelling study predicted that the forces applied by the extensor muscles to stabilise the lumbar spine would be greater in spines that have a larger sagittal curvature (lordosis). Because the force-generating capacity of a muscle is related to its size, it was hypothesised that the size of the extensor muscles in a subject would be related to the size of their lumbar lordosis. Magnetic resonance imaging (MRI) data were obtained, together with age, height, body mass and back pain status, from 42 female subjects. The volume of the extensor muscles (multifidus and erector spinae) caudal to the mid-lumbar level was estimated from cross-sectional area measurements in axial T1-weighted MRIs spanning the lumbar spine. Lower lumbar curvature was determined from sagittal T1-weighted images. A stepwise linear regression model was used to determine the best predictors of muscle volume. The mean lower lumbar extensor muscle volume was 281 cm(3) (SD = 49 cm(3) ). The mean lower lumbar curvature was 30 ° (SD = 7 °). Five subjects reported current back pain and were excluded from the regression analysis. Nearly half the variation in muscle volume was accounted for by the variables age (standardised coefficient, B = -3.2, P = 0.03) and lower lumbar curvature (B = 0.47, P = 0.002). The results support the hypothesis that extensor muscle volume in the lower lumbar spine is related to the magnitude of the sagittal curvature; this has implications for assessing muscle size as an indicator of muscle strength.
Journal of Anatomy 04/2013; 222(6). DOI:10.1111/joa.12047
• ##### Article: Complementary medicine and general practice in an urban setting: a decade on
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ABSTRACT: Aim: To conduct a follow-up survey ascertaining changes in usage, referral rate, beliefs and attitudes towards complementary and alternative medicine (CAM) during the last decade. Background: In many countries, CAM use is reported to be substantial and increasing. Methods: A questionnaire was posted to all GPs registered with the Liverpool Primary Care Trust. Respondents were asked whether they treat, refer, endorse or discuss eight common CAM therapies and about their views on National Health Service (NHS) funding, effectiveness, CAM training needs and theoretical validity of each therapy. Comparisons were made between these results and those collected in 1999. Findings: The response rate was low (32%) compared with the 1999 survey (52%). The main findings were similar to the most popular therapies still being acupuncture, hypnotherapy and chiropractic and the least being aromatherapy, reflexology and medical herbalism. GPs felt most comfortable with acupuncture, with greater belief in its theoretical validity, a greater desire for training and a greater support for acupuncture to receive NHS funding than for the other CAM therapies under question. Opinions about homeopathy had become less supportive. Overall, GPs were less likely to endorse CAMs than previously shown (38% versus 19%).
Primary Health Care Research & Development 04/2013; 15(03):1-6. DOI:10.1017/S1463423613000182
• ##### Article: Benzofuran-, benzothiophene-, indazole- and benzisoxazole-quinones: Excellent substrates for NAD(P)H:quinone oxidoreductase 1
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ABSTRACT: A series of heterocyclic quinones based on benzofuran, benzothiophene, indazole and benzisoxazole has been synthesized, and evaluated for their ability to function as substrates for recombinant human NAD(P)H:quinone oxidoreductase (NQO1), a two-electron reductase upregulated in tumor cells. Overall, the quinones are excellent substrates for NQO1, approaching the reduction rates observed for menadione.
Bioorganic & medicinal chemistry 04/2013; 21(11). DOI:10.1016/j.bmc.2013.03.071
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##### Article: Dietary supplements and prostate cancer: A systematic review of double-blind, placebo-controlled randomised clinical trials
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ABSTRACT: Dietary supplements are popular among patients with prostate cancer (PC). The objective of this systematic review was to critically examine double-blind, placebo-controlled randomised clinical trials (RCTs) of non-herbal dietary supplements and vitamins (NHDS) for evidence that prostate specific antigen (PSA) levels were reduced in PC patients. Five databases were searched from their inception through December 2012 to identify studies that met our inclusion criteria. Methodological quality was independently assessed by two reviewers using the Cochrane tool. Eight RCTs met the eligibility criteria and were of high methodological quality. The following supplements were tested: isoflavones (genistein, daidzein, and glycitein), minerals (Se) or vitamins (vitamin D) or a combination of antioxidants, bioflavonoids, carotenoids, lycopenes, minerals (Se, Zn, Cu, and Mg), phytoestrogens, phytosterols, vitamins (B2, B6, B9, B12, C, and E), and other substances (CoQ10 and n-acetyl-l cysteine). Five RCTs reported no significant effects compared with placebo. Two RCTs reported that a combination of antioxidants, isoflavones, lycopenes, minerals, plant oestrogens and vitamins significantly decreased PSA levels compared with placebo. One RCT did not report differences in PSA levels between the groups. In conclusion, the hypothesis that dietary supplements are effective treatments for PC patients is not supported by sound clinical evidence. There are promising data for only two specific remedies, which contained a mixture of ingredients, but even for these supplements, additional high quality evidence is necessary before firm recommendations would be justified.
Maturitas 04/2013; 75(2). DOI:10.1016/j.maturitas.2013.03.006
• ##### Article: RESPONSE.

Medicine and science in sports and exercise 04/2013; 45(4):802. DOI:10.1249/MSS.0b013e318282184a
• ##### Article: Can you kill your enemy by giving homeopathy? Response by Posadzki and Ernst

International Journal of Clinical Practice 04/2013; 67(4):386-7. DOI:10.1111/ijcp.12110
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##### Article: Adverse effects of homeopathy: A systematic review of published case reports and case series - Response by Posadzki and Ernst
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ABSTRACT: Linked Comment: Jackson. Int J Clin Pract 2013; 67: 385. Linked Comment: Walach et al. Int J Clin Pract 2013; 67: 385–6. Linked Comment: Posadzki and Ernst. Int J Clin Pract 2013; 67: 386–7. Linked Comment: Grimes. Int J Clin Pract 2013; 67: 387. Linked Comment: Tournier et al. Int J Clin Pract 2013; 67: 388–9.
International Journal of Clinical Practice 04/2013; 67(4):389. DOI:10.1111/ijcp.12140
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##### Article: Quiet Eye and Choking
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ABSTRACT: PURPOSE: The quiet eye (QE) is a characteristic of highly skilled perceptual and motor performance that has been shown to be sensitive to increases in anxiety. The present study is the first to examine changes in the QE at the precise point of performance failure under heightened anxiety. QE durations were compared for the first, penultimate (next to last), and final (missed) putts taken in a pressurized 'shootout' task. To probe the effects of anxiety more specifically, differences in the component of the QE that occurred before (QE-pre), during (QE-online), and after (QE-dwell) putter movement were examined. METHODS: Fifty expert golfers (average handicap of 3.6) performed putts under pressure until they missed ('shootout'). Gaze was recorded throughout with an ASL Mobile Eye Tracker. Total QE, pre-programming QE (the proportion of QE that occurred prior to backswing; QE-pre), online control QE (the proportion of QE that occurred during the putting stroke; QE-online), and QE dwell (the proportion of QE that occurred after putter-ball contact; QE-dwell), were calculated for the first, penultimate, and final putts. RESULTS: Total QE duration was significantly shorter for the final (missed) putt compared to the first and penultimate (successful) putts. Although QE-pre duration was similar across the three putts, the components of the QE occurring during (QE-online) and after (QE-dwell) putter movement were significantly shorter on the missed putt. CONCLUSION: Performance failure under pressure appears to be due to disruptions in attentional control once movement has been initiated. These findings support the predictions of attentional control theory (ACT) and suggest that the QE may have an online control function, providing visual sensory information as the movement unfolds.
Medicine and science in sports and exercise 03/2013; 45(10). DOI:10.1249/MSS.0b013e31829406c7
• ##### Article: Performance Enhancement Effects of Fédération Internationale de Football Association’s “The 11+” Injury Prevention Training Program in Youth Futsal Players
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ABSTRACT: OBJECTIVE:: To evaluate if Fédération Internationale de Football Association's "The 11+" injury prevention program improves physical fitness and technical performance in youth futsal players. DESIGN:: Randomized cohort study. SETTING:: Futsal club. PARTICIPANTS:: Thirty-six futsal players (17.3 ± 0.7 years). INTERVENTION:: Players were randomized to an intervention group (n = 18) or a control group (n = 18). Intervention group performed "The 11+" twice per week for 12 weeks. MAIN OUTCOME MEASURES:: Isokinetic testing to access maximal quadriceps (Q) and hamstring (H) strength, vertical jump (squat jump, SJ; countermovement jump, CMJ), 5-m and 30-m sprint, agility, slalom, and balance performances were also measured. RESULTS:: Intervention group increased (P < 0.05) quadriceps concentric (14.7%-27.3%) and hamstrings concentric (9.3%-13.3%) and eccentric (12.7%) peak torque. Intervention group improved functional H:Q ratio by 1.8% to 8.5% (P < 0.05). Intervention group improved (P < 0.05) SJ (13.8%) and CMJ (9.9%) and 5-m and 30-m sprint (8.9% and 3.3%, respectively), agility (4.7%), and slalom (4.8%) performances. Intervention group also improved balance, by decreasing the number of falls by 30% in the nondominant limb. No changes were observed in control group. CONCLUSIONS:: The results suggest that 'The 11+' can be used as an effective conditioning means for improving physical fitness and technical performance of youth futsal players.
Clinical journal of sport medicine: official journal of the Canadian Academy of Sport Medicine 03/2013; 23(4):318-20. DOI:10.1097/JSM.0b013e318285630e
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##### Article: A protocol to determine valid VO2max in young cystic fibrosis patients
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ABSTRACT: OBJECTIVES: Measuring aerobic fitness (V˙O2max) via a maximal cardiopulmonary exercise test is an important clinical tool in cystic fibrosis. This study sought to establish: (1) the validity of traditional criteria to verify maximal efforts during a ramp cardiopulmonary exercise test; and (2) whether V˙O2 measured during an exhaustive cardiopulmonary exercise test represents a valid V˙O2max in paediatric patients, using a subsequent exhaustive supramaximal (Smax) exercise test. DESIGN: Cross-sectional. METHODS: Fourteen patients (7-18 years; 10 males) completed an exhaustive ramp test to determine V˙O2max. Following 15-min recovery, Smax (110% ramp peak power output) was performed. RESULTS: Ramp test V˙O2peak was significantly higher than V˙O2 documented at traditional endpoint criteria, including a RER of 1.00 (0.99±0.47Lmin(-1) vs. 1.83±0.78Lmin(-1), p<0.001) and 1.10 (1.36±0.59Lmin(-1) vs. 1.83±0.78Lmin(-1), p<0.001), despite 100% of patients satisfying these two criteria. Only 23% and 75% of patients satisfied the 95% age-predicted heart rate (HR) maximum and 180bmin(-1) criteria. Whilst mean ramp and SmaxV˙O2peak were not significantly different (1.83±0.78Lmin(-1) vs. 1.82±0.67Lmin(-1); p=0.88), at the individual level Smax elicited a 'meaningful' (>9%) increase in V˙O2peak (range 9.9-38.3%) compared with V˙O2peak from the ramp test in 3 of 14 cases (21.4%). CONCLUSIONS: Traditional criteria significantly underestimate V˙O2max in young cystic fibrosis patients. Conversely, Smax can confirm when 'true'V˙O2max is achieved. The use of Smax following cardiopulmonary exercise test represents an appropriate method to measure V˙O2max in young cystic fibrosis patients.
03/2013; 16(6). DOI:10.1016/j.jsams.2013.01.010
• ##### Article: Prevalence of complementary and alternative medicine (CAM) use by menopausal women: A systematic review of surveys
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ABSTRACT: Large proportions of women have turned to complementary and alternative medicine (CAM) for relief from their menopausal symptoms. This highlights the need for more rigorous research into CAM. This article is aimed at critically reviewing surveys that examine the prevalence of CAM use by menopausal women worldwide. Eleven databases were searched for peer-reviewed surveys published in any language between 01 January 2000 and 27 October 2012. The bibliographies of the retrieved articles and relevant book chapters were also hand searched. Twenty-six surveys were identified, and they included a total of 32,465 menopausal women. The majority of these surveys were of poor methodological quality. Based on 6 surveys, 32.9% of women stated they were current/regular CAM users. Based on 9 surveys, 50.5% of women reported that they used CAM specifically for their menopausal symptoms. The average 12-month prevalence of CAM use was 47.7% (range: 33.1-56.2). Fifty-five percent of women did not disclose their use of CAM to their healthcare professional. The majority of women sought information about CAM from the media. The most popular CAM modality was herbal medicine, followed by soy/phytoestrogens, evening primrose oil, relaxation and yoga. There are a large number of predominantly low-quality surveys monitoring the prevalence of CAM use among menopausal women worldwide. The available evidence suggests that the prevalence of CAM use is high.
Maturitas 03/2013; 75(1). DOI:10.1016/j.maturitas.2013.02.005
• ##### Article: Effects of Nitrate on the Power–Duration Relationship for Severe-Intensity Exercise
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ABSTRACT: Purpose: The power asymptote (critical power [CP]) and curvature constant (W') of the power-duration relationship dictate the tolerance to severe-intensity exercise. We tested the hypothesis that dietary nitrate supplementation would increase the CP and/or the W' during cycling exercise. Methods: In a double-blind, randomized, crossover study, nine recreationally active male subjects supplemented their diet with either nitrate-rich concentrated beetroot juice (BR; 2 × 250 mL·d, ∼8.2 mmol·d nitrate) or a nitrate-depleted BR placebo (PL; 2 × 250 mL·d, ∼0.006 mmol·d nitrate). In each condition, the subjects completed four separate severe-intensity exercise bouts to exhaustion at 60% of the difference between the gas exchange threshold and the peak power attained during incremental exercise (60% Δ), 70% Δ, 80% Δ, and 100% peak power, and the results were used to establish CP and W'. Results: Nitrate supplementation improved exercise tolerance during exercise at 60% Δ (BR, 696 ± 120 vs PL, 593 ± 68 s; P < 0.05), 70% Δ (BR, 452 ± 106 vs PL, 390 ± 86 s; P < 0.05), and 80% Δ (BR, 294 ± 50 vs PL, 263 ± 50 s; P < 0.05) but not 100% peak power (BR, 182 ± 37 vs PL, 166 ± 26 s; P = 0.10). Neither CP (BR, 221 ± 27 vs PL, 218 ± 26 W) nor W' (BR, 19.3 ± 4.6 vs PL, 17.8 ± 3 kJ) were significantly altered by BR. Conclusion: Dietary nitrate supplementation improved endurance during severe-intensity exercise in recreationally active subjects without significantly increasing either the CP or the W'.
Medicine and science in sports and exercise 03/2013; 45(9). DOI:10.1249/MSS.0b013e31828e885c
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##### Article: High medial plantar pressures during barefoot running are associated with increased risk of ankle inversion injury in Royal Marine recruits
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ABSTRACT: Background: Ankle inversion injury is common in military populations but associated biomechanical risk factors are largely unknown. This prospective study examined the association between pressure and kinematic variables, and ankle inversion injury risk in Royal Marine (RM) recruits. It was hypothesised that a more medially concentrated pressure at the heel-off phase of stance, greater impulse and peak pressure at the first metatarsal head, greater peak rearfoot eversion angle and greater eversion excursion would be associated with ankle inversion injury. Methods: Data from 145 male, injury-free RM recruits were recorded in week-2 of a 32-week military training programme. Each recruit completed five running trials at 3.6 ms(-1), along a 2m pressure plate. Kinematic data were simultaneously recorded. Injuries sustained during the training programme were prospectively recorded. Findings: Data from eleven recruits who had suffered an ankle inversion injury during RM training were compared with 20 uninjured controls. The injury group displayed a higher (P<0.05) peak first metatarsal pressure, peak metatarsal impulse and more medially concentrated pressure at heel-off than control recruits. There were no differences in kinematic variables between groups. The injury group had a lower body mass than controls (P<0.05). Interpretations: The findings from this study support existing literature, providing evidence that high medial concentration of vertical forces when running are associated with increased ankle inversion injury risk. This may be due to the lateral ankle ligaments being less accustomed to loading, resulting in relatively weak lateral ligaments, or ligaments less able to deal with fatigue than those of the control group.
Gait & posture 03/2013; 38(4). DOI:10.1016/j.gaitpost.2013.02.001
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##### Article: The Efficacy of Irvingia Gabonensis Supplementation in the Management of Overweight and Obesity: A Systematic Review of Randomized Controlled Trials
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ABSTRACT: ABSTRACT The aim of this systematic review was to evaluate the evidence from randomized controlled trials (RCTs) involving the use of the African Bush Mango, Irvingia gabonensis for body weight reduction in obese and overweight individuals. Electronic and nonelectronic searches were conducted to identify relevant RCTs. The bibliographies of located articles were also searched. No age, gender, or language restrictions were imposed. The reporting quality of identified RCTs was assessed using a methodological checklist adapted from the Consolidated Standard of Reporting Trials Statement and Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Two reviewers independently determined eligibility and assessed the reporting quality of included studies. Three RCTs were identified, and all were included. The RCTs all had flaws in the reporting of their methodology. All RCTs reported statistically significant reductions in body weight and waist circumference favoring I. gabonensis over placebo. The results from the RCTs also suggest positive effects of I. gabonensis supplementation on the blood lipid profile. Adverse events included headache and sleep difficulty. Due to the paucity and poor reporting quality of the RCTs, the effect of I. gabonensis on body weight and related parameters are unproven. Therefore, I. gabonensis cannot be recommended as a weight loss aid. Future research in this area should be more rigorous and better reported.
Journal of Dietary Supplements 03/2013; 10(1):29-38. DOI:10.3109/19390211.2012.760508
• ##### Article: Heat stress impairs repeated jump ability after competitive elite soccer games
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ABSTRACT: Mohr, M and Krustrup, P. Heat stress impairs repeated jump ability after competitive elite soccer games. J Strength Cond Res 27(3): 683-689, 2013-This study examined the effect of environmental heat stress on repeated jump performance after elite competitive soccer games. Male elite soccer players (n = 19) from 2 Scandinavian teams participated (age: 26.7 ± 1.0 years, height: 181.7 ± 1.1 cm, body mass: 75.8 ± 1.0 kg). The players had a Yo-Yo IR2 performance of 1,032 ± 42 m (range: 920-1,400 m). The players took part in the Champions League Qualification, where 6 games (3 home and 3 away) were played. The home games took place at an average ambient temperature of 12.2 ± 0.5° C (control game; CON) and the away games in hot conditions (30.0 ± 0.3° C; HOT). In the resting condition (Baseline) and immediately after CON and HOT, the players performed a repeated countermovement jump (CMJ) test consisting of 5 jumps separated by 5 seconds of recovery. Game-induced body mass loss was determined based on change in body mass after correction for fluid intake. The net loss of body mass was 3.1 ± 0.3% in HOT, which was higher (p < 0.05) than in CON (1.7 ± 0.2%). Mean CMJ performance after HOT was 37.9 ± 1.1 cm, which was 6.0% lower (p < 0.05) than Baseline (40.3 ± 1.1 cm) and tended (p = 0.08) to be lower than in the CON (39.6 ± 1.2 cm). The mean CMJ performance after CON was not different from Baseline. Peak CMJ performance after HOT was 41.1 ± 1.1 cm, which was not different from either Baseline or CON (42.0 ± 1.1 and 41.7 ± 1.2 cm, respectively). The relative decline in repeated CMJ performance from Baseline to after HOT correlated (r = 0.60; p < 0.05) to relative net loss in body mass during HOT. This study demonstrates that repeated CMJ performance deteriorates after a soccer game played in warm environmental settings, which is partly associated with severe dehydration.
The Journal of Strength and Conditioning Research 03/2013; 27(3):683-9. DOI:10.1097/JSC.0b013e31825c3266
• ##### Article: No effect of acute L-arginine supplementation on O2 cost or exercise tolerance
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ABSTRACT: The extent to which dietary supplementation with the nitric oxide synthase (NOS) substrate, L-arginine (ARG), impacts on NO production and NO-mediated physiological responses is controversial. This randomised, double blinded, cross-over study investigated the effects of acute ARG supplementation on NO biomarkers, O(2) cost of exercise and exercise tolerance in humans. In one experiment, 15 subjects completed moderate- and severe-intensity running bouts after acute supplementation with 6 g ARG or placebo (PLA). In another experiment, eight subjects completed moderate- and severe-intensity cycling bouts after acute supplementation with 6 g ARG plus 25 g of carbohydrate (ARG + CHO) or an energy-matched dose of carbohydrate alone (CHO). The plasma nitrite concentration was not different after ARG (Pre: 204 ± 79; Post: 241 ± 114 nM; P > 0.05) or ARG + CHO consumption (Pre: 304 ± 57; Post: 335 ± 116 nM; P > 0.05). During moderate-intensity exercise, the steady-state pulmonary [Formula: see text] was not different, relative to the respective placebo conditions, after ARG (PLA: 2,407 ± 318, ARG: 2,422 ± 333 mL min(-1)) or ARG + CHO (CHO: 1,695 ± 304, ARG + CHO: 1,712 ± 312 mL min(-1)) ingestion (P > 0.05). The tolerable duration of severe exercise was also not significantly different (P > 0.05) after ingesting ARG (PLA: 551 ± 140, ARG: 552 ± 150 s) or ARG + CHO (CHO: 457 ± 182, ARG + CHO: 441 ± 221 s). In conclusion, acute dietary supplementation with ARG or ARG + CHO did not alter biomarkers of NO synthesis, O(2) cost of exercise or exercise tolerance in healthy subjects.
Arbeitsphysiologie 02/2013; 113(7). DOI:10.1007/s00421-013-2593-z
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##### Article: Sitting Behavior and Obesity Evidence from the Whitehall II Study
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ABSTRACT: BACKGROUND: Prospective studies report associations between indicators of time spent sitting and obesity risk. Most studies use a single indicator of sedentary behavior and are unable to clearly identify whether sedentary behavior is a cause or a consequence of obesity. PURPOSE: To investigate cross-sectional and prospective associations between multiple sitting time indicators and obesity and examine the possibility of reverse causality. METHODS: Using data from the Whitehall II cohort, multiple logistic models were fitted to examine associations between prevalent obesity (BMI ≥30) at Phase 5 (1997-1999), and incident obesity between Phases 5 and 7 (2003-2004) across four levels of five sitting exposures (work sitting, TV viewing, non-TV leisure-time sitting, leisure-time sitting, and total sitting). Using obesity data from three prior phases (1985-1988, 1991-1993; and recalled weight at age 25 years), linear regression models were fitted to examine the association between prior obesity and sitting time at Phase 5. Analyses were conducted in 2012. RESULTS: None of the sitting exposures were associated with obesity either cross-sectionally or prospectively. Obesity at one previous measurement phase was associated with a 2.43-hour/week (95% CI=0.07, 4.78) increase in TV viewing; obesity at three previous phases was associated with a 7.42-hour/week (95% CI=2.7, 12.46) increase in TV-viewing hours/week at Phase 5. CONCLUSIONS: Sitting time was not associated with obesity cross-sectionally or prospectively. Prior obesity was prospectively associated with time spent watching TV per week but not other types of sitting.
American journal of preventive medicine 02/2013; 44(2):132-138. DOI:10.1016/j.amepre.2012.10.009
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##### Article: Dietary nitrate supplementation improves team sport-specific intense intermittent exercise performance
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ABSTRACT: Recent studies have suggested that dietary inorganic nitrate (NO(3) (-)) supplementation may improve muscle efficiency and endurance exercise tolerance but possible effects during team sport-specific intense intermittent exercise have not been examined. We hypothesized that NO(3) (-) supplementation would enhance high-intensity intermittent exercise performance. Fourteen male recreational team-sport players were assigned in a double-blind, randomized, crossover design to consume 490 mL of concentrated, nitrate-rich beetroot juice (BR) and nitrate-depleted placebo juice (PL) over ~30 h preceding the completion of a Yo-Yo intermittent recovery level 1 test (Yo-Yo IR1). Resting plasma nitrite concentration ([NO(2) (-)]) was ~400 % greater in BR compared to PL. Plasma [NO(2) (-)] declined by 20 % in PL (P < 0.05) and by 54 % in BR (P < 0.05) from pre-exercise to end-exercise. Performance in the Yo-Yo IR1 was 4.2 % greater (P < 0.05) with BR (1,704 ± 304 m) compared to PL (1,636 ± 288 m). Blood [lactate] was not different between BR and PL, but the mean blood [glucose] was lower (3.8 ± 0.8 vs. 4.2 ± 1.1 mM, P < 0.05) and the rise in plasma [K(+)] tended to be reduced in BR compared to PL (P = 0.08). These findings suggest that NO(3) (-) supplementation may promote NO production via the nitrate-nitrite-NO pathway and enhance Yo-Yo IR1 test performance, perhaps by facilitating greater muscle glucose uptake or by better maintaining muscle excitability. Dietary NO(3) (-) supplementation improves performance during intense intermittent exercise and may be a useful ergogenic aid for team sports players.
Arbeitsphysiologie 02/2013; 113(7). DOI:10.1007/s00421-013-2589-8
• ##### Article: V̇O2max is not altered by self-pacing during incremental exercise: Reply to the letter of Alexis R. Mauger

Arbeitsphysiologie 02/2013; 113(2). DOI:10.1007/s00421-012-2563-x
• ##### Article: Effects of Pacing Strategy on Work Done above Critical Power during High-Intensity Exercise
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ABSTRACT: Purpose: We investigated the influence of pacing strategy on the work completed above critical power (CP) before exhaustion (W>CP) and the peak V˙O2 attained during high-intensity cycling. Methods: After the determination of VO(2max) from a ramp incremental cycling (INC) test and the estimation of the parameters of the power-duration relationship for high-intensity exercise (i.e., CP and W') from a 3-min all-out cycling test (AOT), eight male subjects completed a cycle test to exhaustion at a severe-intensity constant work rate (CWR) estimated to result in exhaustion in 3 min and a self-paced 3-min cycling time trial (SPT). Results: The VO(2max) determined from INC was 4.24 ± 0.69 L · min(-1), and the CP and the W' estimated from AOT were 260 ± 60 W and 16.5 ± 4.0 kJ, respectively. W>CP during SPT was not significantly different from W>CP during CWR (15.3 ± 5.6 and 16.6 ± 7.4 kJ, respectively), and these values were also similar to W(>CP) during INC (16.4 ± 4.0 kJ) and W' estimated from AOT. The peak VO(2) during SPT was not significantly different from peak VO(2) during CWR (4.20 ± 0.77 and 4.14 ± 0.75 L · min(-1), respectively), and these values were similar to the VO(2max) determined from INC and the peak VO(2) during AOT (4.10 ± 0.79 L · min(-1)). Conclusion: Exhaustion during high-intensity exercise coincides with the achievement of the same peak VO2 (VO(2max)) and the completion of the same W>CP, irrespective of the work rate forcing function (INC or CWR) or pacing strategy (enforced pace or self-paced). These findings indicate that exhaustion during high-intensity exercise is based on highly predictable physiological processes, which are unaffected when pacing strategy is self-selected.
Medicine and science in sports and exercise 01/2013; 45(7). DOI:10.1249/MSS.0b013e3182860325
• ##### Article: Influence of dietary nitrate supplementation on human skeletal muscle metabolism and force production during maximum voluntary contractions
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ABSTRACT: Dietary nitrate supplementation, which enhances nitric oxide (NO) bioavailability, has previously been shown to contribute to improved exercise performance by reducing both oxygen cost and energy expenditure. In contrast, previous studies have indicated that NO can lower force production in vitro. To examine the role of dietary nitrates in regulating force generation under normal physiological conditions, we undertook an extended nitrate supplementation regime and determined force output and energy cost with a repeated isometric maximum voluntary contraction (MVC) protocol. In a double-blind, randomized, crossover design, eight participants received 0.5 l/day of nitrate-rich (BR) or nitrate-depleted (PL) beetroot juice for 15 days and completed an exercise protocol consisting of 50 MVCs at 2.5 h, 5 days and 15 days after the beginning of the supplementation period. No significant reduction in force output was determined for BR relative to PL for the peak contraction, the mean or the end force, and no significant time effect was found over the course of the supplementation period. There was a reduction in the mean PCr cost of exercise averaged over the BR supplementation trials, but this did not reach statistical significance for end exercise (BR 15.10 ± 4.14 mM, PL 17.10 ± 5.34 mM, P = 0.06) or the mean throughout the protocol (BR 15.96 ± 4.14 mM, PL 17.79 ± 4.51 mM, P = 0.06). However, a significant reduction in PCr cost per unit force output was found for BR at end exercise (P = 0.04). These results indicate that, under normal physiological conditions, increased NO bioavailability is not associated with a reduction of force-generating capability in human skeletal muscle and confirm that nitrate supplementation reduces the PCr cost of force production.
Pflügers Archiv - European Journal of Physiology 01/2013; 465(4). DOI:10.1007/s00424-013-1220-5
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##### Article: .VO2max is not altered by self-pacing during incremental exercise
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ABSTRACT: We tested the hypothesis that incremental cycling to exhaustion that is paced using clamps of the rating of perceived exertion (RPE) elicits higher $\dot{V}_{{{\text{O}}_{2} { \max }}}$ values compared to a conventional ramp incremental protocol when test duration is matched. Seven males completed three incremental tests to exhaustion to measure $\dot{V}_{{{\text{O}}_{2} { \max }}}$ . The incremental protocols were of similar duration and included: a ramp test at 30 W min−1 with constant cadence (RAMP1); a ramp test at 30 W min−1 with cadence free to fluctuate according to subject preference (RAMP2); and a self-paced incremental test in which the power output was selected by the subject according to prescribed increments in RPE (SPT). The subjects also completed a $\dot{V}_{{{\text{O}}_{2} { \max }}}$ ‘verification’ test at a fixed high-intensity power output and a 3-min all-out test. No difference was found for $\dot{V}_{{{\text{O}}_{2} { \max }}}$ between the incremental protocols (RAMP1 = 4.33 ± 0.60 L min−1; RAMP2 = 4.31 ± 0.62 L min−1; SPT = 4.36 ± 0.59 L min−1; P > 0.05) nor between the incremental protocols and the peak $\dot{V}_{{{\text{O}}_{2} }}$ measured during the 3-min all-out test (4.33 ± 0.68 L min−1) or the $\dot{V}_{{{\text{O}}_{2} { \max }}}$ measured in the verification test (4.32 ± 0.69 L min−1). The integrated electromyogram, blood lactate concentration, heart rate and minute ventilation at exhaustion were not different (P > 0.05) between the incremental protocols. In conclusion, when test duration is matched, SPT does not elicit a higher $\dot{V}_{{{\text{O}}_{2} { \max }}}$ compared to conventional incremental protocols. The striking similarity of $\dot{V}_{{{\text{O}}_{2} { \max }}}$ measured across an array of exercise protocols indicates that there are physiological limits to the attainment of $\dot{V}_{{{\text{O}}_{2} { \max }}}$ that cannot be exceeded by self-pacing.
Arbeitsphysiologie 01/2013; 113(2). DOI:10.1007/s00421-012-2478-6
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##### Article: Influence of intermittent hypoxic training on muscle energetics and exercise tolerance
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ABSTRACT: Intermittent hypoxic training (IHT) is sometimes used by athletes to enhance 'non-hematological' physiological adaptations to simulated altitude. We investigated whether IHT would result in greater improvements in muscle energetics and exercise tolerance compared to work-matched intermittent normoxic training (INT). Nine physically-active males completed three weeks of intensive single-leg knee-extensor exercise training. Each training session consisted of 25 min of IHT (F(I)O(2) 14.5 ± 0.1%) with the experimental leg and 25 min of INT with the alternate leg which served as a control. Before and after the training intervention, the subjects completed a test protocol consisting of a bout of sub-maximal constant-work-rate exercise, a 24 s high-intensity exercise bout to quantify the phosphocreatine recovery time constant ([PCr]-τ), and an incremental test to the limit of tolerance. The tests were completed in normoxia and hypoxia, in both the INT and IHT legs. Muscle metabolism was assessed non-invasively using (31)P-magnetic resonance spectroscopy. Improvements in the time-to-exhaustion during incremental exercise were not significantly different between training conditions either in normoxia (INT: 28 ± 20 vs. IHT: 25 ± 9 %, P=0.86) or hypoxia (INT: 21 ± 10 vs. IHT: 15 ± 11 %, P=0.29). In hypoxia, [PCr]-τ was speeded slightly but significantly more post-IHT compared to post-INT (-7.3 ± 2.9 vs. -3.7 ± 1.7 s, P<0.01) but changes in muscle metabolite concentrations during exercise were essentially not different between IHT and INT. Under the conditions of this investigation, IHT does not enhance muscle metabolic responses or incremental exercise performance compared to INT.
Journal of Applied Physiology 01/2013; 114(5). DOI:10.1152/japplphysiol.01331.2012
• ##### Article: Dietary Nitrate and O2 Consumption during Exercise
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ABSTRACT: Recent studies have investigated the influence of dietary nitrate supplementation on the physiological responses to exercise. Specifically, it has been reported that enhancing nitric oxide (NO) bioavailability through supplementation of the diet with nitrate salts or nitrate-rich beetroot juice reduces the O(2) cost of exercise and improves exercise performance. The lower O(2) cost for a given sub-maximal work rate following nitrate ingestion indicates that muscle efficiency is enhanced either as a consequence of a reduced energy cost of contraction or enhanced mitochondrial efficiency. The positive effects of nitrate supplementation on the O(2) cost of sub-maximal exercise can be manifested acutely (i.e. 2.5 h following ingestion) and maintained for at least 15 days if supplementation is continued. Most recently, the influence of dietary nitrate supplementation on time trial performance in competitive cyclists has been investigated. Studies have shown a 1-2% reduction in the time to complete time trial distances between 4 and 16 km. The dose of nitrate that has been shown to improve exercise efficiency can readily be achieved through the consumption of 0.5 litre of beetroot juice or an equivalent high-nitrate foodstuff. Following a 5- to 6-mmol bolus of nitrate, plasma [nitrite] typically peaks within 2-3 h and remains elevated for a further 6-9 h before declining towards baseline. Therefore, consuming nitrate approximately 3 h prior to competition or training is recommended if athletes wish to explore the ergogenic potential of nitrate supplementation.
01/2013; 59:29-35. DOI:10.1159/000342062
• ##### Article: Evidence and theory into practice in different health care contexts: A call for more translational science
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ABSTRACT: There is increasing interest in how to help people with a mental health problem to initiate and maintain an increase in physical activity. Some studies have focused on patient preferences for support, through surveys and interviews. Relatively little is known about whether existing behaviour change theories, and their respective constructs as targets for change to mediate behaviour change (and frequently applied to clients in non-clinical populations) are appropriate and useful for peoplewith differentmental health conditions. Relatively little is known about howmuch and the type of support needed, and provided by whom, is needed to facilitate both an increase andmaintenance in physical activity (or reduction in sedentary behaviour) of sufficient amount to impact on mental health. These represent significant challenges in translating our research to real world settings and helping those most in need. MENPA remains committed to publishing high quality research that not only builds on the evidence base supporting the role of physical activity as a mental health promotion strategy but also translational research that tackles these critical questions.
Mental Health and Physical Activity 01/2013; 7(1). DOI:10.1016/j.mhpa.2013.06.007
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##### Article: Markers of Muscle Damage and Performance Recovery after Exercise in the Heat
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ABSTRACT: Purpose: This study aimed to determine whether competitive intermittent exercise in the heat affects recovery, aggravates markers of muscle fiber damage, and delays the recovery of performance and muscle glycogen stores. Methods: Plasma creatine kinase, serum myoglobin, muscle glycogen, and performance parameters (sprint, endurance, and neuromuscular testing) were evaluated in 17 semiprofessional soccer players before, immediately after, and during 48 h of recovery from a match played in 43°C (HOT) and compared with a control match (21°C with similar turf and setup). Results: Muscle temperature was ∼1°C higher (P < 0.001) after the game in HOT compared with control and reached individual values between 39.9°C and 41.1°C. Serum myoglobin levels increased by more than threefold after the matches (P < 0.01), but values were not different in HOT compared with control, and they were similar to baseline values after 24 h of recovery. Creatine kinase was significantly elevated both immediately and 24 h after the matches, but the response after HOT was reduced compared with control. Muscle glycogen responses were similar across trials and remained depressed for more than 48 h after both matches. Sprint performance and voluntary muscle activation were impaired to a similar extent after the matches (sprint by ∼2% and voluntary activation by ∼1.5%; P < 0.05). Both of these performance parameters as well as intermittent endurance capacity (estimated by a Yo-Yo IR1 test) were fully recovered 48 h after both matches. Conclusion: Environmental heat stress does not aggravate the recovery response from competitive intermittent exercise associated with elevated muscle temperatures and markers of muscle damage, delayed resynthesis of muscle glycogen, and impaired postmatch performance.
Medicine and science in sports and exercise 12/2012; 45(5). DOI:10.1249/MSS.0b013e31827ded04
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##### Article: Detection and isolation of human serum autoantibodies that recognize oxidatively modified autoantigens
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ABSTRACT: The breakdown of human immune tolerance to self-proteins occurs by a number of mechanisms, including post-translational modifications of host molecules by reactive oxygen, nitrogen or chlorine species. This has led to great interest in detecting serum autoantibodies raised against small quantities of oxidatively modified host proteins in patients with autoimmune inflammatory diseases, such as rheumatoid arthritis. Here, we provide protocols for the preparation and chemical characterization of oxidatively modified protein antigens, and procedures for their use in immunoblotting and ELISAs which detect autoantibodies against these antigens in clinical samples. These gel electrophoresis- and plate reader-based immunochemical methods sometimes suffer from low analytical specificity and/or sensitivity when used for serum autoantibody detection. This is often because a single solid phase protein (antigen) is exposed to a complex mixture of serum proteins which undergo non-specific binding. Therefore more sensitive/specific techniques are required, to detect autoantibodies specifically directed against oxidatively modified proteins. To address this, we describe novel affinity chromatography protocols by which purified autoantibodies are isolated from small volumes (< 1ml) of serum. We have also developed strategies to conjugate sub-milligram amounts of isolated immunoglobulins and other proteins to fluorophores. The above set of methods will help facilitate the discovery of novel diagnostic autoantibodies in patients.
• ##### Article: The influence of motion control shoes on the running gait of mature and young females
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ABSTRACT: Background: This study compared the running gait of mature and young females, and investigated the effect of a motion control shoe. First, it was hypothesised that in a neutral shoe, mature females would display significantly greater rearfoot eversion, knee internal rotation and external adductor moments when compared to a younger group. Secondly, the motion control shoe would reduce rearfoot eversion and knee internal rotation in both groups. Thirdly it was hypothesised that the motion control shoe would increase knee external adductor moment, through an increase in knee varus and moment arm. Methods: 15 mature (40-60 years) and 15 young (18-25 years) females performed 10 running trials at 3.5ms(-1)±5% over a force platform. Two shoes were tested, the Adidas Supernova Glide (neutral), and the Adidas Supernova Sequence (motion control). Ankle and knee joint dynamics were analysed for the right leg, and the mean of ten trials was calculated. Joint moments were calculated using inverse dynamics. Findings: In the neutral condition, mature females presented greater peak rearfoot eversion, knee internal rotation, and external adductor moments than young females (p<0.05). A motion control shoe significantly reduced peak rearfoot eversion and knee internal rotation among both groups (p<0.05). No between shoe differences in knee external adductor moment were observed. Interpretation: A motion control shoe is recommended to reduce risk of injury associated with rearfoot eversion and knee internal rotation in mature females. However since the knee external adductor moment is a variable commonly associated with medial knee loading it is suggested that alternative design features are required to influence this moment.
Gait & posture 10/2012; 37(3). DOI:10.1016/j.gaitpost.2012.07.026
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##### Article: Soccer Improves Fitness and Attenuates Cardiovascular Risk Factors in Hypertensive Men
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ABSTRACT: Introduction: The present study investigated the fitness and health effects of medium-term soccer training for untrained hypertensive middle-age men. Methods: Thirty-three untrained males (31-54 yr) with mild-to-moderate hypertension were randomized 2:1 to a soccer training group (STG, two 1-h sessions per week, n = 22, 68% on medication) and a doctor advice group receiving traditional physician-guided recommendations on cardiovascular risk factor modification (DAG, n = 11, 73% on medication). Two-way repeated-measures ANOVA time-group statistics was applied. Results: During soccer training, average HR was 155 ± 9 bpm or 85% ± 7% HRmax. In STG, systolic and diastolic blood pressures decreased (P < 0.01) over 6 months from 151 ± 10 to 139 ± 10 mm Hg and from 92 ± 7 to 84 ± 6 mm Hg, respectively, with smaller (P < 0.05) decreases in DAG (from 153 ± 8 to 145 ± 8 mm Hg and from 96 ± 6 to 93 ± 6 mm Hg, respectively). In STG, V˙O2max increased (P < 0.01) from 32.6 ± 4.9 to 35.4 ± 6.6 mL·min-1·kg-1 and relative V˙O2 during cycling at 100 W was lowered (P < 0.05) from 55% ± 7% to 50% ± 8% V˙O2max over 6 months, with no changes in DAG. In STG, resting HR was lowered by 8 ± 11 bpm (P < 0.05), and the augmentation index (a measure of arterial stiffness) was lowered (P < 0.05) by 7.3 ± 14.0 over 6 months, with no change in DAG. Conclusions: Six months of soccer training improved aerobic fitness, reduced blood pressure, and resulted in an array of other favorable effects on cardiovascular risk profile for untrained middle-age hypertensive men. Soccer training, therefore, may be a better nonpharmacological treatment for hypertensive men than traditional physician-guided advice.
Medicine and science in sports and exercise 10/2012; 45(3). DOI:10.1249/MSS.0b013e3182777051
• ##### Article: The use of Yo-Yo IR1 and Andersen testing for fitness and maximal heart rate assessments of 6-10 yr old school children
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ABSTRACT: We evaluated a sub-maximal and maximal version of the Yo-Yo IR1 childrens test (YYIR1C) and the Andersen test for fitness and maximal HR assessments of children aged 6-10. Two repetitions of the YYIR1C and Andersen tests were carried out within one week by 6-7 and 8-9 year olds (grade 0, n=17; grade 2, n=16) and six weeks apart by 9-10 year olds (grade 3, n=49). Grade (G) 0-2's also performed an incremental treadmill test (ITT). G2's had a better (p<0.05) YYIR1 test (84%; 994±399 (±SD) vs 536±218 m) and Andersen test performance (10%; 1050±71 vs 955±56 m) than G0's. For G0-2's YYIR1C, Andersen and ITT HRpeak were 205±11, 207±9 and 203±7 b.p.m., respectively (Andersen>ITT, p<0.05) and for G3's YYIR1C and Andersen HRpeak were 208±9 and 204±9 b.p.m. respectively (YYIR1C>Andersen, p<0.05). Submaximal YYIR1C HR was inversely correlated (p<0.05) with YYIR1C performance (r=-0.54 to -0.67) and VO2peak (r=-0.42). The 6-wk change in submaximal HR correlated with the change in YYIR1C performance (r=-0.42 to -0.53, p<0.05). In conclusion, YYIR1C and Andersen tests are simple and inexpensive intermittent field tests that can detect differences in fitness levels and determine maximal HR of 6-10 year old children. Additionally, submaximal YYIR1C testing can be used for frequent non-exhaustive fitness assessments.
The Journal of Strength and Conditioning Research 09/2012; 112(6). DOI:10.1519/JSC.0b013e318270fd0b
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##### Article: Response to Schwerla

Clinical Rheumatology 08/2012; 31(9):1409. DOI:10.1007/s10067-012-2067-4
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##### Article: The acute effects of physical activity on cigarette cravings: Systematic review and meta-analysis with individual participant data (IPD)
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ABSTRACT: Aims: To conduct an updated systematic review and the first meta-analysis of experimental trials investigating the acute effects of short bouts of physical activity (PA) on strength of desire (SoD) and desire to smoke (DtS) using individual participant data (IPD). Methods: A systematic review of literature and IPD meta-analyses included trials assessing the acute effects of shorts bouts of PA on SoD and DtS among temporarily abstaining smokers not using pharmaceutical aids for smoking cessation. Authors of eligible studies were contacted and raw IPD were obtained. Two-stage and one-stage IPD random-effects meta-analyses were conducted. Participants engaging in PA were compared against control participants, using post-intervention SoD and DtS with baseline adjustments. Results: A two-stage IPD meta-analysis assessing effects of PA on SoD yielded an average standardized mean difference (SMD) between PA and control conditions (across 15 primary studies) of -1.91 [95% confidence interval (CI): -2.59 to -1.22]. A two-stage IPD meta-analysis assessing effects of PA on DtS yielded an average SMD between PA and control conditions (across 17 primary studies) of -2.03 (95% CI: -2.60 to -1.46). Additional meta-analyses, including those using a one-stage model, those including only parallel arm studies and meta-analyses comparing only moderate exercise against a control condition, showed significant craving reduction following PA. Despite a high degree of between-study heterogeneity, effects sizes of all primary studies were in the same direction, with PA showing a greater reduction in cravings compared with controls. Conclusions: There is strong evidence that physical activity acutely reduces cigarette craving.
• ##### Article: Contamination and adulteration of herbal medicinal products (HMPs): An overview of systematic reviews
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ABSTRACT: Purpose: The aim of this overview of systematic reviews is to summarise and critically evaluate the evidence from systematic reviews of the adulteration and contamination of herbal medicinal products (HMPs). Methods: Five electronic databases were searched to identify all relevant systematic reviews. Results: Twenty-six systematic reviews met our inclusion criteria. The most commonly HMPs were adulterated or contaminated with dust, pollens, insects, rodents, parasites, microbes, fungi, mould, toxins, pesticides, toxic heavy metals and/or prescription drugs. The most severe adverse effects caused by these adulterations were agranulocytosis, meningitis, multi-organ failure, perinatal stroke, arsenic, lead or mercury poisoning, malignancies or carcinomas, hepatic encephalopathy, hepatorenal syndrome, nephrotoxicity, rhabdomyolysis, metabolic acidosis, renal or liver failure, cerebral edema, coma, intracerebral haemorrhage, and death. Adulteration and contamination of HMPs were most commonly noted for traditional Indian and Chinese remedies, respectively. Conclusions: Collectively these data suggest that there are reasons for concerns with regards to the quality of HMPs. Adulteration and contamination of HMPs can cause serious adverse effects. More stringent quality control and its enforcement seem to be necessary to avoid health risks.
European Journal of Clinical Pharmacology 07/2012; 69(3). DOI:10.1007/s00228-012-1353-z
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##### Article: Traditional Chinese medicine for cancer?

British Journal of Cancer 07/2012; 107(3):405. DOI:10.1038/bjc.2012.282
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##### Article: Calibration of the GENEA accelerometer for assessment of physical activity intensity in children
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ABSTRACT: OBJECTIVES: The purpose of the study was to establish activity intensity cut-points for the GENEA accelerometer via calibration with oxygen consumption (V˙⁡O(2)). DESIGN: The study was a lab-based validation and calibration study. METHODS: Forty-four children, aged 8-14 years, completed eight activities (ranging from lying supine to a medium paced run) whilst wearing GENEA accelerometers at three locations (each wrist and at the right hip), an ActiGraph GT1M at the hip and a portable gas analyser. ActiGraph output and V˙⁡O(2) were used for assessment of concurrent and criterion validity, respectively. Pearson's r correlations were used to assess validity of the GENEA monitors at each location and location-specific activity intensity cut-points were established via Receiver Operator Characteristic curve analysis. RESULTS: The GENEA showed good criterion validity at both wrist locations (right: r=.900; left: r=.910, both p<0.01), although the hip-mounted monitor demonstrated significantly higher criterion validity (r=.965, p<0.05). Similar results were shown for concurrent validity (right: r=.830; left: r=.845; hip: r=.985, all p<0.01). GENEAs, irrespective of wear location, accurately discriminated between all activity intensities (sedentary, light, moderate and vigorous) with the hip mounted monitor recording the largest area under the curve for each intensity (area under the curve=0.94-0.99). CONCLUSIONS: The GENEA can be used to accurately assess children's physical activity intensity when worn at either the wrist or the hip.
07/2012; 16(2). DOI:10.1016/j.jsams.2012.05.013
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##### Article: Extensive Monitoring Through Multiple Blood Samples in Professional Soccer Players
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ABSTRACT: The aim of this study was to make a comprehensive gathering of consecutive detailed blood samples from professional soccer players, and to analyze different blood parameters in relation to seasonal changes in training and match exposure.Blood samples were collected five times during a six months period and analyzed for 37 variables in 27 professional soccer players from the best Danish league. Additionally, players were tested for body composition, VO2max and physical performance by the Yo-Yo intermittent endurance sub-max test (IE2).Multiple variations in blood parameters occurred during the observation period, including a decrease in hemoglobin and an increase in hematocrit as the competitive season progressed. Iron and transferrin was stabile, whereas ferritin showed a decrease at the end of the season. IgA and IgM increased in the period with basal physical training and at the end of the season. Leucocytes decreased with increased physical training. Lymphocytes decreased at the end of the season. VO2max decreased towards the end of the season whereas no significant changes were observed in the IE2 test.The regular blood samples from elite soccer players reveal significant changes that may be related to changes in training pattern, match exposure or length of the match-season. Especially the end of the preparation-season and at the end of the competitive season seem to be time points were the blood-derived values indicate that the players are under excessive physical strain and might be more subjected to a possible overreaching/overtraining conditions.We suggest that regular analyzes of blood samples could be an important initiative to optimize training adaptation, training load and game participation, but sampling has to be regular and a database has to be build for each individual player.
The Journal of Strength and Conditioning Research 06/2012; 27(5). DOI:10.1519/JSC.0b013e3182653d17
• ##### Article: Aristolochia, a herbal treatment to die for?

Maturitas 06/2012; 73(2):85-6. DOI:10.1016/j.maturitas.2012.06.005
• ##### Article: Brief health professional-provided interventions may lead to small improvements in physical activity

Evidence-based medicine 06/2012; 18(1). DOI:10.1136/ebmed-2012-100761
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##### Article: Physiological Responses and Physical Performance during Football in the Heat
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ABSTRACT: To examine the impact of hot ambient conditions on physical performance and physiological responses during football match-play. Two experimental games were completed in temperate (∼ 21°C; CON) and hot ambient conditions (∼ 43°C; HOT). Physical performance was assessed by match analysis in 17 male elite players during the games and a repeated sprint test was conducted after the two game trials. Core and muscle temperature were measured and blood samples were obtained, before and after the games. Muscle and core temperatures were ∼ 1°C higher (P<0.05) in HOT (40.3 ± 0.1 and 39.5 ± 0.1°C, respectively) compared to CON (39.2 ± 0.1 and 38.3 ± 0.1°C). Average heart rate, plasma lactate concentration, body weight loss as well as post-game sprint performance were similar between the two conditions. Total game distance declined (P<0.05) by 7% and high intensity running (>14 km ⋅ h(-1)) by 26% in HOT compared to CON), but peak sprint speed was 4% higher (P<0.05) in HOT than in CON, while there were no differences in the quantity or length of sprints (>24 km ⋅ h(-1)) between CON and HOT. In HOT, success rates for passes and crosses were 8 and 9% higher (P<0.05), respectively, compared to CON. Delta increase in core temperature and absolute core temperature in HOT were correlated to total game distance in the heat (r = 0.85 and r = 0.53, respectively; P<0.05), whereas, total and high intensity distance deficit between CON and HOT were not correlated to absolute or delta changes in muscle or core temperature. Total game distance and especially high intensity running were lower during a football game in the heat, but these changes were not directly related to the absolute or relative changes in core or muscle temperature. However, peak sprinting speed and execution of successful passes and crosses were improved in the HOT condition.
PLoS ONE 06/2012; 7(6):e39202. DOI:10.1371/journal.pone.0039202
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##### Article: Influence of exercise intensity on skeletal muscle blood flow, O2 extraction and O2 uptake on-kinetics
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ABSTRACT: Key points  Following the start of low-intensity exercise in healthy humans, it has been established that the kinetics of muscle O(2) delivery is faster than, and does not limit, the kinetics of muscle O(2) uptake.  Direct data are lacking, however, on the question of whether O(2) delivery might limit O(2) uptake kinetics during high-intensity exercise.  In this study, we made frequent measurements of muscle blood flow, arterial-to-venous O(2) difference (a- difference) and O(2) uptake following the onset of multiple transitions of both low-intensity and high-intensity knee-extension exercise in the same subjects.  We show that although blood flow kinetics is slower for high-intensity compared with low-intensity exercise, this does not result in slower O(2) uptake kinetics.  These results indicate that muscle O(2) delivery does not limit O(2) uptake during knee-extension exercise in healthy humans.
The Journal of Physiology 06/2012; 590(Pt 17):4363-76. DOI:10.1113/jphysiol.2012.233064
• ##### Article: Guided Imagery for Non-Musculoskeletal Pain: A Systematic Review of Randomized Clinical Trials
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ABSTRACT: Our previous review of the literature concluded that there is encouraging evidence that guided imagery alleviates musculoskeletal pain, but the value of guided imagery in the management of non-musculoskeletal pain remains uncertain. The objective of this systematic review was to assess the effectiveness of guided imagery as a treatment option for non-musculoskeletal pain. Six databases were searched from their inception to February 2011. Randomized clinical trials were considered if they investigated guided imagery in human patients with any type of non-musculoskeletal pain in any anatomical location and assessed pain as a primary outcome measure. Trials of motor imagery and hypnosis were excluded. The selection of studies, data extraction, and validation were performed independently by two reviewers. Fifteen randomized clinical trials met the inclusion criteria. Their methodological quality was generally poor. Eleven trials found that guided imagery led to a significant reduction of non-musculoskeletal pain. Four studies found no change in non-musculoskeletal pain with guided imagery in comparison with progressive relaxation, standard care, or no treatment. The evidence that guided imagery alleviates non-musculoskeletal pain is encouraging but remains inconclusive.
Journal of pain and symptom management 06/2012; 44(1):95-104. DOI:10.1016/j.jpainsymman.2011.07.014
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##### Article: Translating theory and evidence into practice: What is the role of health professionals?

Mental Health and Physical Activity 06/2012; 5(1):1–3. DOI:10.1016/j.mhpa.2012.04.002
• ##### Article: Hydration Status, Fluid Intake and Electrolyte Losses in Youth Soccer Players.
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ABSTRACT: The purpose of the study was to determine the hydration status, fluid intake and electrolyte losses of 21 male professional youth soccer players (age 17.1 ± 0.7 yr) training in a cool environment. Pre- and post training measurements of body mass, urine (freezing point osmolality method) and sweat concentration (flame emission spectroscopy) were collected. Fourteen players were found to be hypohydrated prior to training. The amount of fluid lost due to exercise equated to a 1.7 % loss in body mass, which equated to a gross dehydration loss of 0.5 %. Overall, the soccer players replaced 46 ± 88% of sweat loss during training and only four remained hypohydrated after training. No significant correlations between sweat loss and sweat concentrations of Na+ (r = -0.11, P = 0.67), K+ (r = 0.14, P = 0.58) were found, but there was a significant correlation with Mg2+ (r = -0.58, P < 0.009). This study found large variability in pre-training hydration status which the players were able to rehydrate during the training sessions. However, given the numbers starting training in a hypohydrated state, adequate hydration status prior to training should be considered by youth players, coaches and sports science support staff.
International journal of sports physiology and performance 05/2012; 7(4).
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##### Article: Activity Classification Using the GENEA: Optimum Sampling Frequency and Number of Axes
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ABSTRACT: The GENEA shows high accuracy for classification of sedentary, household, walking, and running activities when sampling at 80 Hz on three axes. It is not known whether it is possible to decrease this sampling frequency and/or the number of axes without detriment to classification accuracy. The purpose of this study was to compare the classification rate of activities on the basis of data from a single axis, two axes, and three axes, with sampling rates ranging from 5 to 80 Hz. Sixty participants (age, 49.4 yr (6.5 yr); BMI, 24.6 kg·m (3.4 kg·m)) completed 10-12 semistructured activities in the laboratory and outdoor environment while wearing a GENEA accelerometer on the right wrist. We analyzed data from single axis, dual axes, and three axes at sampling rates of 5, 10, 20, 40, and 80 Hz. Mathematical models based on features extracted from mean, SD, fast Fourier transform, and wavelet decomposition were built, which combined one of the numbers of axes with one of the sampling rates to classify activities into sedentary, household, walking, and running. Classification accuracy was high irrespective of the number of axes for data collected at 80 Hz (96.93% ± 0.97%), 40 Hz (97.4% ± 0.73%), 20 Hz (96.86% ± 1.12%), and 10 Hz (97.01% ± 1.01%) but dropped for data collected at 5 Hz (94.98% ± 1.36%). Sampling frequencies >10 Hz and/or more than one axis of measurement were not associated with greater classification accuracy. Lower sampling rates and measurement of a single axis would result in a lower data load, longer battery life, and higher efficiency of data processing. Further research should investigate whether a lower sampling rate and a single axis affects classification accuracy when considering a wider range of activities.
Medicine and science in sports and exercise 05/2012; 44(11):2228-34. DOI:10.1249/MSS.0b013e31825e19fd
• ##### Article: Acute and Subacute Neck Pain

Annals of internal medicine 05/2012; 156(9):668; author reply 669. DOI:10.1059/0003-4819-156-9-201205010-00017

Journal of pain and symptom management 05/2012; 43(5):e1-2. DOI:10.1016/j.jpainsymman.2012.02.003
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##### Article: Influence of training status and maturity on pulmonary O 2 uptake recovery kinetics following cycle and upper body exercise in girls
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ABSTRACT: The influence of training status on pulmonary VO(2) recovery kinetics, and its interaction with maturity, has not been investigated in young girls. Sixteen prepubertal (Pre: trained (T, 11.4 ± 0.7 years), 8 untrained (UT, 11.5 ± 0.6 years)) and 8 pubertal (Pub: 8T, 14.2 ± 0.7 years; 8 UT, 14.5 ± 1.3 years) girls completed repeat transitions from heavy intensity exercise to a baseline of unloaded exercise, on both an upper and lower body ergometer. The VO2 recovery time constant was significantly shorter in the trained prepubertal and pubertal girls during both cycle (Pre: T, 26 ± 4 vs. UT, 32 ± 6; Pub: T, 28 ± 2 vs. UT, 35 ± 7 s; both p < .05) and upper body exercise (Pre: T, 26 ± 4 vs. UT, 35 ± 6; Pub: T, 30 ± 4 vs. UT, 42 ± 3 s; both p < .05). No interaction was evident between training status and maturity. These results demonstrate the sensitivity of VO(2) recovery kinetics to training in young girls and challenge the notion of a "maturational threshold" in the influence of training status on the physiological responses to exercise and recovery.
Pediatric exercise science 05/2012; 24(2):246-61.
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##### Article: Patterning of affective responses during a graded exercise test in children and adolescents
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ABSTRACT: Past studies have shown the patterning of affective responses during a graded exercise test (GXT) in adult and male adolescent populations, but none have explored the patterns in adolescent girls or younger children. This study explored the patterning of affective responses during a GXT in adolescents and younger children. Forty-nine children (21 male and 28 female) aged between 8-14 years (10.8 ± 1.8 years) completed a GXT. Ventilatory threshold (VT) was identified. At the end of each incremental step, participants reported affective valence. Results revealed that affective valence assessed by the Feeling Scale (FS) significantly declined from the onset of exercise until the point of VT in the younger children, but remained relatively stable in the adolescents. Exercise above the VT brought about significant declines in affective valence regardless of age or sex, but the decrease was significantly greater in adolescents. Results suggest it may be preferable to prescribe lower exercise intensities (below VT) for children, compared with adolescents, to ensure a positive affective response.
Pediatric exercise science 05/2012; 24(2):275-88.
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##### Article: New insights in paediatric exercise metabolism
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ABSTRACT: Research in paediatric exercise metabolism has been constrained by being unable to interrogate muscle in vivo. Conventionally, research has been limited to the estimation of muscle metabolism from observations of blood and respiratory gases during maximal or steady state exercise and the analysis of a few muscle biopsies taken at rest or post-exercise. The purpose of this paper is to review how the introduction of 31P-magnetic resonance spectroscopy and breath-by-breath oxygen uptake kinetics studies has contributed to current understanding of exercise metabolism during growth and maturation. Methodologically robust studies using 31P-magnetic resonance spectroscopy and oxygen uptake kinetics with children are sparse and some data are in conflict. However, it can be concluded that children respond to exercise with enhanced oxygen utilization within the myocyte compared with adults and that their responses are consistent with a greater recruitment of type I muscle fibres. Changes in muscle metabolism are age, maturation- and sex-related and dependent on the intensity of the exercise challenge. The introduction of experimental models such as “priming exercise” and “work-to-work” transitions provide intriguing avenues of research into the mechanisms underpinning exercise metabolism during growth and maturation.
Journal of Sport and Health Science 05/2012; 1(1):18–26. DOI:10.1016/j.jshs.2011.12.001
• ##### Article: Cardiorespiratory Fitness, Fatness, and Blood Pressure Associations in Nigerian Youth
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ABSTRACT: This study aimed to examine the independent associations of cardiorespiratory fitness (CRF) and body fatness with resting blood pressure (BP) in children (9-11 yr) and adolescents (12-15 yr) in Benue State of Nigeria. A total of 3243 children (n = 1017) and adolescents (n = 2226) were evaluated for aerobic fitness, body fatness, resting preexercise BP and recovery BP at minutes 1, 5, and 10 after a progressive aerobic cardiovascular endurance run test. Regression models, controlling for age and recovery BP at 1, 5, and 10 min after the progressive aerobic cardiovascular endurance run, determined the associations of independent variables with the dependent variables. Fatness and fitness were independent predictors of resting BP among participants, and the relationship of fatness with BP was more robust in adolescents than in children. In all cases, the relationships were stronger in boys than in girls. Combined fitness and fatness in predicting BP was modest (R = 1%-3%) after controlling for age and postexercise BP. Postexercise BP was a major determinant of resting BP in both groups (R = 23%-93%). In adolescents, fatter boys had 1.9 times likelihood of systolic HTN compared with leaner peers. Systolic and diastolic BP scores varied by fit-fat groups, the fit-low-fat group demonstrated the most favorable BP profiles, whereas the unfit-high-fat group showed the most adverse profiles. Irrespective of fatness, participants with higher CRF had more favorable BP profiles compared with their fat-unfit peers.
Medicine and science in sports and exercise 04/2012; 44(10):1978-85. DOI:10.1249/MSS.0b013e31825ae19d
• ##### Article: Influence of acute dietary nitrate supplementation on 50 mile time trial performance in well-trained cyclists
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ABSTRACT: Dietary nitrate supplementation has been reported to improve short distance time trial (TT) performance by 1-3 % in club-level cyclists. It is not known if these ergogenic effects persist in longer endurance events or if dietary nitrate supplementation can enhance performance to the same extent in better trained individuals. Eight well-trained male cyclists performed two laboratory-based 50 mile TTs: (1) 2.5 h after consuming 0.5 L of nitrate-rich beetroot juice (BR) and (2) 2.5 h after consuming 0.5 L of nitrate-depleted BR as a placebo (PL). BR significantly elevated plasma [NO(2) (-)] (BR: 472 ± 96 vs. PL: 379 ± 94 nM; P < 0.05) and reduced completion time for the 50 mile TT by 0.8 % (BR: 136.7 ± 5.6 vs. PL: 137.9 ± 6.4 min), which was not statistically significant (P > 0.05). There was a significant correlation between the increased post-beverage plasma [NO(2) (-)] with BR and the reduction in TT completion time (r = -0.83, P = 0.01). Power output (PO) was not different between the conditions at any point (P > 0.05) but oxygen uptake ([Formula: see text]O(2)) tended to be lower in BR (P = 0.06), resulting in a significantly greater PO/[Formula: see text]O(2) ratio (BR: 67.4 ± 5.5 vs. PL: 65.3 ± 4.8 W L min(-1); P < 0.05). In conclusion, acute dietary supplementation with beetroot juice did not significantly improve 50 mile TT performance in well-trained cyclists. It is possible that the better training status of the cyclists in this study might reduce the physiological and performance response to NO(3) (-) supplementation compared with the moderately trained cyclists tested in earlier studies.
Arbeitsphysiologie 04/2012; 112(12). DOI:10.1007/s00421-012-2397-6
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##### Article: Mechanisms for Improved Running Economy in Beginner Runners
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ABSTRACT: Controversy surrounds whether running mechanics make good predictors of running economy (RE) with little known about the development of an economical running gait. The aim of this study was to identify if mechanical or physiological variables changed during 10 wk of running in beginners and whether these changes could account for any change in RE. A 10-wk running program (10 wkRP) was completed by 10 female beginner runners. A bilateral three-dimensional kinematic and kinetic analysis, in addition to RE and lower body flexibility measurements, was performed before and after the 10 wkRP. The Balke-Ware graded walking exercise test was performed before and after the 10 wkRP to determine VO2max. Seven kinematic and kinetic variables significantly changed from before to after training, in addition to a significant decrease in calf flexibility (27.3° ± 6.3° vs 23.9° ± 5.6°, P < 0.05). A significant improvement was seen in RE (224 ± 24 vs 205 ± 27 mL · kg(-1) · km(-1), P < 0.05) and treadmill time to exhaustion (16.4 ± 3.2 vs 17.3 ± 2.8 min, P < 0.05); however, VO2max remained unchanged from before to after training (34.7 ± 5.1 vs 34.3 ± 5.6 mL · kg(-1) · min(-1)). Stepwise regression analysis showed three kinematic variables to explain 94.3% of the variance in change in RE. They were a less extended knee at toe off (P = 0.004), peak dorsiflexion occurring later in stance (P = 0.001), and a slower eversion velocity at touchdown (P = 0.042). The magnitude of change for each variable was 1.5%, 4.7%, and 34.1%, respectively. These results show that beginner runners naturally developed their running gait as they became more economical runners.
Medicine and science in sports and exercise 04/2012; 44(9):1756-63. DOI:10.1249/MSS.0b013e318255a727
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##### Article: Three generalizability studies of the components of perceived coach support
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ABSTRACT: Coaches are important providers of social support, but what influences us to perceive our coaches as supportive or unsupportive? We investigated the extent to which perceptions of coach support reflect characteristics of athletes and coaches, as well as relational components. In three studies, athletes judged the actual or hypothetical supportiveness of various coaches. The methods of generalizability theory permitted us to conclude that perceptions of coach support primarily reflected relational components, with characteristics both of athletes and coaches also independently playing (lesser) roles. These findings suggest that athletes may systematically disagree on the supportiveness of their coaches.
Journal of Sport and Exercise Psychology 04/2012; 34(2):238-51.
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##### Article: Is lavender an anxiolytic drug? A systematic review of randomised clinical trials
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ABSTRACT: Lavender (Lavandula angustifolia) is often recommended for stress/anxiety relief and believed to possess anxiolytic effects. To critically evaluate the efficacy/effectiveness of lavender for the reduction of stress/anxiety. Seven electronic databases were searched to identify all relevant studies. All methods of lavender administration were included. Data extraction and the assessment of the methodological quality of all included trials were conducted by two independent reviewers. Fifteen RCTs met the inclusion criteria. Two trials scored 4 points on the 5-point Jadad scale, the remaining 13 scored two or less. Results from seven trials appeared to favour lavender over controls for at least one relevant outcome. Methodological issues limit the extent to which any conclusions can be drawn regarding the efficacy/effectiveness of lavender. The best evidence suggests that oral lavender supplements may have some therapeutic effects. However, further independent replications are needed before firm conclusions can be drawn.
Phytomedicine: international journal of phytotherapy and phytopharmacology 03/2012; 19(8-9):825-35. DOI:10.1016/j.phymed.2012.02.013
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##### Article: Ecological validity of the Yo-Yo SFIE2 test
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ABSTRACT: The present study investigated the movement pattern of Portuguese top-level futsal referees (n=16) during competitive games and the ecological validity of the new Yo-Yo Sideways-Forwards Intermittent Endurance level 2 test (Yo-Yo SFIE2). Total distance covered (TD), high-intensity running (HIR), sprinting (SPR), and sideways running (Sw) during matches were 5.78±0.24 (±SEM), 0.77±0.08, 0.17±0.02 and 1.61±0.28 km, respectively, with peak 5-min values of 0.50±0.02, 0.12±0.01, 0.05±0.01 and 0.20±0.02 km, respectively. TD, HIR and Sw decreased by 30% (p<0.001), 43% and 60% (p<0.01), respectively from the first to the last 10-min period. Yo-Yo SFIE2 performance was 1205±107 (625-2015) m and showed large correlations with match-values and peak 5-min values for HIR (r=0.58 and 0.68, p<0.01) and SPR (r=0.56 and 0.57, p<0.05). Yo-Yo SFIE2 HR after 4 min [95±1 (87-99) % HRpeak] showed a nearly perfect inverse correlation with Yo-Yo SFIE2 performance (r= -0.90, p<0.001) and large inverse correlations (p<0.05) with match-values and peak 5-min values for HIR (r= -0.55 and -0.71) and SPR (r= -0.57 and -0.55). In conclusion, the Yo-Yo SFIE2 test is movement-specific for top-level futsal referees as high-intensity running and sideways running are important parts of their match activity profile, and maximal and sub-maximal versions of the Yo-Yo SFIE2 test correlates with certain aspects of the physical match performance of top-level futsal referees.
International Journal of Sports Medicine 03/2012; 33(6):432-8. DOI:10.1055/s-0031-1291362
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##### Article: The efficacy of long-term conjugated linoleic acid (CLA) supplementation on body composition in overweight and obese individuals: A systematic review and meta-analysis of randomized clinical trials
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ABSTRACT: Numerous supplements containing conjugated linoleic acid (CLA) are presently being promoted for body weight reduction. The aim of this systematic review is to evaluate the evidence for or against the long-term efficacy of CLA. Electronic searches were conducted to identify relevant randomized clinical trials (RCTs). No restrictions in age, time, or language were imposed. Studies had to be at least 6 months in duration. Three reviewers independently determined the eligibility of studies. Two reviewers independently extracted data and assessed the reporting quality of all RCTs. Fifteen RCTs were identified, and seven were included. Four of the included RCTs had serious flaws in the reporting of their methodology. A meta-analysis revealed a statistically significant difference in weight loss favouring CLA over placebo (mean difference: -0.70 kg; 95% confidence interval: -1.09, -0.32). Our meta-analysis also revealed a small significant difference in fat loss favouring CLA over placebo (MD: -1.33 kg; 95% CI: -1.79, -0.86; I (2) = 54%). The magnitude of these effects is small, and the clinical relevance is uncertain. Adverse events included constipation, diarrhea, and soft stools. The evidence from RCTs does not convincingly show that CLA intake generates any clinically relevant effects on body composition on the long term.
European Journal of Nutrition 03/2012; 51(2):127-34. DOI:10.1007/s00394-011-0253-9
• ##### Article: Modeling the Expenditure and Reconstitution of Work Capacity above Critical Power
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ABSTRACT: The critical power (CP) model includes two constants: the CP and the W' [P = (W' / t) + CP]. The W' is the finite work capacity available above CP. Power output above CP results in depletion of the W' complete depletion of the W' results in exhaustion. Monitoring the W' may be valuable to athletes during training and competition. Our purpose was to develop a function describing the dynamic state of the W' during intermittent exercise. After determination of V˙O(2max), CP, and W', seven subjects completed four separate exercise tests on a cycle ergometer on different days. Each protocol comprised a set of intervals: 60 s at a severe power output, followed by 30-s recovery at a lower prescribed power output. The intervals were repeated until exhaustion. These data were entered into a continuous equation predicting balance of W' remaining, assuming exponential reconstitution of the W'. The time constant was varied by an iterative process until the remaining modeled W' = 0 at the point of exhaustion. The time constants of W' recharge were negatively correlated with the difference between sub-CP recovery power and CP. The relationship was best fit by an exponential (r = 0.77). The model-predicted W' balance correlated with the temporal course of the rise in V˙O(2) (r = 0.82-0.96). The model accurately predicted exhaustion of the W' in a competitive cyclist during a road race. We have developed a function to track the dynamic state of the W' during intermittent exercise. This may have important implications for the planning and real-time monitoring of athletic performance.
Medicine and science in sports and exercise 02/2012; 44(8):1526-32. DOI:10.1249/MSS.0b013e3182517a80
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##### Article: Alternative treatments for breast cancer

European Journal of Clinical Pharmacology 12/2011; 68(5):453-4. DOI:10.1007/s00228-011-1186-1
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##### Article: Rates of recruitment from systematic and opportunistic methods: preliminary results from the DDELPHI study

Trials 12/2011; 12 Suppl 1(Suppl 1):A112. DOI:10.1186/1745-6215-12-S1-A112
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##### Article: Clarifying Assumptions about Intraoperative Stress during Surgical Performance: More Than a Stab in the Dark: Reply

World Journal of Surgery 12/2011; 36(2). DOI:10.1007/s00268-011-1373-3
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##### Article: A-Z of nutritional supplements: Dietary supplements, sports nutrition foods and ergogenic aids for health and performance-Part 27
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ABSTRACT: Welcome to Part 27, where we fi nish 'N' with nitrates and nootkatone and move onto 'O' starting with octacosanol. The fi rst review focuses on what has become quite a hot topic in sport nutrition in the recent years with the BBC leading with a headline in August 2009 that 'Beetroot Juice boosts Stamina'. The BBC was describing a study from Professor Andy Jones' group: in his brief review for Part 27, he describes the link between supplementing the diet with nitrate-rich beetroot juice to enhance NO availability and the consequential proposed mechanisms that could lead to an improvement in exercise performance. The other two reviews deal with substances that are generally found as plant extracts: nootkatone, a chemical found in the essential oil of grapefruit and other plants including cedars, which is used predominantly as a fl avouring compound but also as a natural insecticide; and policosanol, a wheat-germ extract whose main component is octacosanol.
British Journal of Sports Medicine 12/2011; 45(15):1246-8. DOI:10.1136/bjsports-2011-090669
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##### Article: Self-paced exercise performance in the heat after pre-exercise cold-fluid ingestion
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ABSTRACT: Precooling is the pre-exercise reduction of body temperature and is an effective method of improving physiologic function and exercise performance in environmental heat. A practical and effective method of precooling suitable for application at athletic venues has not been demonstrated. To confirm the effectiveness of pre-exercise ingestion of cold fluid without fluid ingestion during exercise on pre-exercise core temperature and to determine whether pre-exercise ingestion of cold fluid alone without continued provision of cold fluid during exercise can improve exercise performance in the heat. Randomized controlled clinical trial. Environmental chamber at an exercise physiology laboratory that was maintained at 32°C, 60% relative humidity, and 3.2 m/s facing air velocity. Seven male recreational cyclists (age = 21 ± 1.5 years, height = 1.81 ± 0.07 m, mass = 78.4 ± 9.2 kg) participated. Participants ingested 900 mL of cold (2°C) or control (37°C) flavored water in 3 300-mL aliquots over 35 minutes of pre-exercise rest. Rectal temperature and thermal comfort before exercise and distance cycled, power output, pacing, rectal temperature, mean skin temperature, heart rate, blood lactate, thermal comfort, perceived exertion, and sweat loss during exercise. During rest, a greater decrease in rectal temperature was observed with ingestion of the cold fluid (0.41 ± 0.16°C) than the control fluid (0.17 ± 0.17°C) over 35 to 5 minutes before exercise (t(6) = -3.47, P = .01). During exercise, rectal temperature was lower after ingestion of the cold fluid at 5 to 25 minutes (t(6) range, 2.53-3.38, P ≤ .05). Distance cycled was greater after ingestion of the cold fluid (19.26 ± 2.91 km) than after ingestion of the control fluid (18.72 ± 2.59 km; t(6) = -2.80, P = .03). Mean power output also was greater after ingestion of the cold fluid (275 ± 27 W) than the control fluid (261 ± 22 W; t(6) = -2.13, P = .05). No differences were observed for pacing, mean skin temperature, heart rate, blood lactate, thermal comfort, perceived exertion, and sweat loss (P > .05). We demonstrated that pre-exercise ingestion of cold fluid is a simple, effective precooling method suitable for field-based application.
Journal of athletic training 12/2011; 46(6):592-599.
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##### Article: Exercise metabolism during moderate-intensity exercise in children with cystic fibrosis following heavy-intensity exercise
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ABSTRACT: Muscle metabolism is increased following exercise in healthy individuals, affecting exercise metabolism during subsequent physical work. We hypothesized that following heavy-intensity exercise (HIE), disease factors in children with cystic fibrosis (CF) would further exacerbate exercise metabolism and perceived exertion during subsequent exercise. Nineteen children with CF (age, 13.4 ± 3.1 years; 10 female) and 19 healthy controls (age, 13.8 ± 3.5 years; 10 female) performed 10 bouts of HIE interspersed with 1 min of recovery between each bout. Three minutes later participants completed a 10-min moderate-intensity exercise (MIE) test (test 1). The MIE test was subsequently repeated 1 h (test 2) and 24 h (test 3) later. Each MIE test was identical and participants exercised at individualized work rates, calibrated by an initial graded maximal cardiopulmonary exercise test, while metabolic and perceived exertion measurements were taken. Following HIE, mixed-model ANOVAs showed a significant difference in oxygen uptake (VO₂) and rating of perceived exertion (RPE) between the 2 groups across the MIE tests (p < 0.01). In controls, VO₂ (L·min⁻¹) and RPE decreased significantly from test 1 to test 2 (p < 0.01) and test 2 to test 3 (p < 0.05). However, in children with CF, VO₂ (L·min⁻¹) increased significantly from test 1 to test 2 (p < 0.01), while RPE did not differ, both VO₂ and RPE decreased significantly from test 2 to test 3 (p < 0.01). In conclusion, following HIE the metabolic and perceptual responses to MIE in both groups decreased 24 h later during test 3. These data show that children with mild-to-moderate CF have the capability to perform HIE and 24 h allows sufficient time for recovery.
Applied Physiology Nutrition and Metabolism 11/2011; 36(6):920-7. DOI:10.1139/h11-117
• ##### Article: Brisk walking reduces ad libitum snacking in regular chocolate eaters during a workplace simulation
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ABSTRACT: Workplace snacking can contribute to obesity. Exercise reduces chocolate cravings but effects on chocolate consumption are unknown. This study investigated the effect of brief exercise on ad libitum consumption during breaks in a computerised task. Seventy-eight regular chocolate eaters, age: 24.90±8.15 years, BMI: 23.56±3.78 kg/m(2) abstained for 2 days. They were randomly assigned to one of four conditions, in a 2 × 2 factorial design, involving either a 15 min brisk walk or quiet rest, and then computerised Stroop tasks with low or high demanding conditions, in three 180 s blocks with a 90 s interval. Throughout, a pre-weighed bowl of chocolates was available for ad libitum eating. A two-way ANOVA revealed no interaction effect of exercise and stress on total chocolate consumption, or main effect of stress, but a main effect of exercise [F(1, 74)=7.12, p<.01]. Mean (SD) chocolate consumption was less (t(73.5)=2.69, 95% CI for difference 3.4-22.9, ES=0.61) for the exercise (15.6 g) than control (28.8 g) group. Exercise also increased affective activation, but there was no mediating effect of change in affect on chocolate consumption. A brief walk may help to reduce ad libitum snacking in regular chocolate eaters.
Appetite 11/2011; 58(1):387-92. DOI:10.1016/j.appet.2011.11.006
• ##### Article: External exercise information provides no immediate additional performance benefit to untrained individuals in time trial cycling
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ABSTRACT: To determine the importance of the provision of external exercise information to the setting of the pacing strategy, in subjects unfamiliar with a cycling task. Twenty-two healthy, untrained cyclists (VO(2max), 50 ± 9 mL-(1)·kg-(1)·min-(1)) were randomly assigned to a control (CON) group or an experimental (EXP) group and two successive 4 km time trials (TT) were performed, separated by a 17 min recovery. The CON group received distance knowledge and distance feedback; the EXP group received neither, but knew that each TT was to be of the same distance. No significant difference in completion time (p>0.05) was observed between the groups for either time to complete TT one (TT1) (CON=443 ± 33 s versus EXP=471 ± 63 s) or time to complete TT two (time trial 2) (CON=461 ± 37 s versus EXP=501 ± 94 s). No significant difference in the final RPE was observed between groups. However, a significant interaction for RPE (rating of perceived exertion)×TT in the CON was observed (F7,70=5.32, p<0.05), with significantly higher RPE values in the final kilometre of TT2 (p<0.05). The lack of any performance improvement in either group, despite the differences in exercise information received, indicates both a reliance on the afferent feedback for setting a pacing strategy and slow learning effect from practice in subjects unfamiliar with the task. The modification in RPE profile observed in the CON, despite no performance improvement, suggests exercise perception based changes may pre-empt work rate based changes and thus not immediately translate to improved performance.
British Journal of Sports Medicine 11/2011; 46(1):49-53. DOI:10.1136/bjsports-2011-090257
• ##### Article: Influence of initial metabolic rate on the power-duration relationship for all-out exercise
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ABSTRACT: A single 3-min all-out cycling test can be used to estimate the power asymptote (critical power, CP) and the curvature constant (W') of the power-duration relationship for severe-intensity exercise. It was hypothesized that when exercise immediately preceding the 3-min all-out test was performed <CP, the CP and W' parameters would be unaffected, whereas preceding exercise >CP would systematically reduce the W' without affecting the CP. Seven physically active males completed 3-min all-out cycling tests in randomized order immediately preceded by: unloaded cycling (control); 6-min moderate; 6-min heavy; 2-min severe (S2); or 4-min severe (S4) intensity exercise. The CP was estimated from the mean power output over the final 30 s of the test and the W' was estimated as the power-time integral above end-test power. There were no significant differences in the CP between control (279 ± 62), moderate (275 ± 52), heavy (286 ± 66 W), S2 (274 ± 55), or S4 (273 ± 65 W). The W' was significantly lower (P < 0.05) in S2 (11.5 ± 2.5) and S4 (8.9 ± 2.2) than in control (16.3 ± 2.3), moderate (17.2 ± 2.4) and heavy (15.6 ± 2.3 kJ). These results support the notion that the W' is predictably depleted only at a power output >CP whereas the CP is independent of the mechanisms which reduce W'.
Arbeitsphysiologie 11/2011; 112(7):2467-73. DOI:10.1007/s00421-011-2214-7
• ##### Article: The Use of Ginger (Zingiber officinale) for the Treatment of Pain: A Systematic Review of Clinical Trials
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ABSTRACT:   Zingiber officinale (Z. officinale), commonly known as ginger, has been widely used traditionally for a variety of medicinal purposes, one of which is for the treatment of pain. The aim of this systematic review was to evaluate the evidence from all human participant clinical trials that have assessed the efficacy of ginger for the treatment of any type of pain.   Following a protocol, multiple databases were sought using comprehensive search strategies for Z. officinale and pain together with a trial filter for randomized or controlled clinical trials. Trials testing the efficacy of Z. officinale, used as a sole oral treatment against a comparison condition in human adults suffering from any pain condition, were included.   Seven published articles, reporting a total of eight trials (481 participants), were included in the review. Six trials (two for osteoarthritis, one for dysmenorrhea, and three for experimentally induced acute muscle pain) found that the use of Z. officinale reduced subjective pain reports. The methodological quality of the included articles was variable. When assessed using the Jadad scale, which allows a score of between 0 and 5 to be given, included articles obtained Jadad ratings ranging from 2 to 5.   Due to a paucity of well-conducted trials, evidence of the efficacy of Z. officinale to treat pain remains insufficient. However, the available data provide tentative support for the anti-inflammatory role of Z. officinale constituents, which may reduce the subjective experience of pain in some conditions such as osteoarthritis. Further rigorous trials therefore seem to be warranted.
Pain Medicine 11/2011; 12(12):1808-18. DOI:10.1111/j.1526-4637.2011.01261.x
• ##### Article: Errors of alternative medicine: Lessons for general practice

The European journal of general practice 11/2011; 18(1):63-6. DOI:10.3109/13814788.2011.626852
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##### Article: Exercise tolerance in intermittent cycling: Application of the critical power concept
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ABSTRACT: This study tested the relevance of the critical power (CP) model for explaining exercise tolerance during intermittent high-intensity exercise with different recovery intensities. After estimation of CP and W' from a 3-min all-out test, seven male subjects completed, in randomized order, a cycle test to exhaustion at a severe-intensity constant-work-rate (S-CWR) and four cycle tests to exhaustion using different intermittent ("work-recovery") protocols (i.e., severe-severe (S-S), severe-heavy (S-H), severe-moderate (S-M), and severe-light (S-L)). The tolerable duration of exercise in S-CWR was 384 ± 48 s, and this was increased by 47%, 100%, and 219% for S-H, S-M, and S-L, respectively (all P < 0.05). Consistent with this, compared with S-CWR (22.9 ± 7.4 kJ), the work done above the CP was significantly greater by 46%, 98%, and 220% for S-H, S-M, and S-L, respectively (all P < 0.05). The slope of the relationship between V˙O₂ and time was significantly reduced for S-H, S-M, and S-L (0.09 ± 0.02, 0.09 ± 0.01, and 0.07 ± 0.02 L·min⁻², respectively) compared with S-CWR (0.16 ± 0.03 L·min⁻², P < 0.05). In addition, the slope of the relationship between integrated EMG and time showed a systematic decline for S-H, S-M, and S-L compared with S-CWR (P < 0.05). These results indicate that, when recovery intervals during intermittent exercise are performed below the CP, exercise tolerance is improved in proportion to the reconstitution of the finite W'. The enhanced exercise tolerance with the lower-intensity recovery intervals was associated with a blunted increase in both V˙O₂ and integrated EMG with time.
Medicine and science in sports and exercise 10/2011; 44(5):966-76. DOI:10.1249/MSS.0b013e31823ea28a
• ##### Article: Midwives' use of complementary/alternative treatments
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ABSTRACT: BACKGROUND: in recent years, several surveys have suggested that many midwives use some form of complementary/alternative therapy (CAT), often without the knowledge of obstetricians. OBJECTIVE: to systematically review all surveys of CAT use by midwives. SEARCH STRATEGY: six electronic databases were searched using text terms and MeSH for CAT and midwifery. SELECTION CRITERIA: surveys were included if they reported quantitative data on the prevalence of CAT use by midwives. DATA COLLECTION AND ANALYSIS: full-text articles of all relevant surveys were obtained. Data were extracted according to pre-defined criteria. MAIN RESULTS: 19 surveys met the inclusion criteria. Most were recent and from the USA. Prevalence data varied but were usually high, often close to 100%. Much use of CATs does not seem to be supported by strong evidence for efficacy. CONCLUSION: most midwives seem to use CATs. As not all CATs are without risks, the issue should be debated openly.
Midwifery 10/2011; 28(6). DOI:10.1016/j.midw.2011.08.013
• ##### Article: Measurement and meaning of markers of reactive species of oxygen, nitrogen and sulfur in healthy human subjects and patients with inflammatory joint disease
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ABSTRACT: Reactive species of oxygen, nitrogen and sulfur play cell signalling roles in human health, e.g. recent studies have shown that increased dietary nitrate, which is a source of RNS (reactive nitrogen species), lowers resting blood pressure and the oxygen cost of exercise. In such studies, plasma nitrite and nitrate are readily determined by chemiluminescence. At sites of inflammation, such as the joints of RA (rheumatoid arthritis) patients, the generation of ROS (reactive oxygen species) and RNS overwhelms antioxidant defences and one consequence is oxidative/nitrative damage to proteins. For example, in the inflamed joint, increased RNS-mediated protein damage has been detected in the form of a biomarker, 3-nitrotyrosine, by immunohistochemistry, Western blotting, ELISAs and MS. In addition to NO•, another cell-signalling gas produced in the inflamed joint is H2S (hydrogen sulfide), an RSS (reactive sulfur species). This gas is generated by inflammatory induction of H2S-synthesizing enzymes. Using zinc-trap spectrophotometry, we detected high (micromolar) concentrations of H2S in RA synovial fluid and levels correlated with clinical scores of inflammation and disease activity. What might be the consequences of the inflammatory generation of reactive species? Effects on inflammatory cell-signalling pathways certainly appear to be crucial, but in the current review we highlight the concept that ROS/RNS-mediated protein damage creates neoepitopes, resulting in autoantibody formation against proteins, e.g. type-II collagen and the complement component, C1q. These autoantibodies have been detected in inflammatory autoimmune diseases.
Biochemical Society Transactions 10/2011; 39(5):1226-32. DOI:10.1042/BST0391226
• ##### Article: Is yoga effective for pain? A systematic review of randomized clinical trials
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ABSTRACT: The objective of this systematic review was to assess the effectiveness of yoga as a treatment option for any type of pain. Seven databases were searched from their inception to February 2011. Randomized clinical trials were considered if they investigated yoga in patients with any type of pain and if they assessed pain as a primary outcome measure. The 5-point Jadad scale was used to assess methodological quality of studies. The selection of studies, data extraction and quality assessment were performed independently by two reviewers. Ten randomized clinical trials (RCTs) met the inclusion criteria. Their methodological quality ranged between 1 and 4 on the Jadad scale. Nine RCTs suggested that yoga leads to a significantly greater reduction in pain than various control interventions such as standard care, self care, therapeutic exercises, relaxing yoga, touch and manipulation, or no intervention. One RCT failed to provide between group differences in pain scores. It is concluded that yoga has the potential for alleviating pain. However, definitive judgments are not possible.
Complementary therapies in medicine 10/2011; 19(5):281-7. DOI:10.1016/j.ctim.2011.07.004
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