Research in Sports Medicine An International Journal

We evaluated the change in body mass including fat mass and skeletal muscle mass in one ultracyclist whilst cycling 1,000 km in 48 hours at a constant intensity of ∼48% VO(2)max, corresponding to a heart rate frequency of ∼105 ± 5 bpm. A 1 kg fat mass decrease resulted, with the largest decrease occurring between the 12th and the 24th hour. No steady state in metabolism was observed and no regular decrease of subcutaneous adipose tissue resulted. This result is backed up by the nuclear magnetic resonance (NMR) urine analysis. Body water increase with simultaneous dehydration is possibly due to endocrine-induced renal water retention, in order to maintain metabolism processes that are required for energy supply and blood flow during very prolonged exercise. Both applied methods, the anthropometric and the bioelectrical impedance analysis, analyse fluid accumulation--especially in the skinfolds of the lower extremities--apparently incorrectly as an increase in body mass and not as an increase in fluids.

We describe the changes of body composition in the female overall winner of the Deutschlandlauf 2007 over 17 stages from the northeast to the southwest of Germany with average daily running stages of 70.9 km to cover the total distance of 1,200 km. Determined by bioelectrical impedance analysis, body mass (BM) increased, percent body fat (% BF) decreased, and percent body water as well as lean body mass (LBM) increased. Skeletal muscle mass and % BF as determined by an anthropometric method showed no changes. This data show, that this female runner achieved an excellent performance and that it is possible for a woman to beat all the men. This type of analysis provides a unique opportunity to gain insight into the physiological changes during multiday running in ultraendurance athletes.

The aim of this unique study was to consider the relationship between folate and vitamin B(12) on homocyst(e)ine (Hcy) concentration in an apparently healthy cohort of Welsh young people. A cohort of 179, 12-13 year olds (88 boys and 91 girls) were measured for Hcy, folate, vitamin B(12), adiposity, and dietary habits. Boys had significantly higher waist circumference and folate concentration than girls. Folate was negatively associated with Hcy in both sexes, whereas vitamin B(12) was negatively associated with Hcy in boys only. Adiposity was not associated with Hcy. Folate was an independent predictor of Hcy in both sexes, whilst vitamin B(12) was an independent determinant of Hcy in boys only. Familial history of cardiovascular disease (CVD) risk factors was identified in 69% of the children with elevated Hcy (> or = 8.5 mumol.L(-1)). Young people might be encouraged to increase their folate intake through diet, particularly by increasing their consumption of leafy vegetables and fruit. Further research is necessary to determine the exact contribution of genetics and diet on Hcy levels in young people, and whether Hcy levels during childhood and adolescence might influence future CVD risk.

This study sought to identify runner characteristics or symptoms that could distinguish those finishers developing exercise-associated hyponatremia (EAH) from those not developing EAH in a 161-km ultramarathon. Of 310 finishers, 207 (67%) underwent postrace blood studies. Twelve (6%) finishers had EAH (blood sodium range 131-134 mmol/L). Experience at 161-km ultramarathons was lower (p = 0.01) and blood creatine kinase (CK) concentration was higher (p = 0.04) among those with EAH than those not developing EAH. Blood sodium and CK concentration were negatively correlated (p = 0.0015, r = -0.22). There were no group differences in age, sex, regular running experience, weekly training distance, use of sodium supplements during training, immediately postrace sodium palatability and thirst ratings, body mass change, urination frequency, nonsteroidal anti-inflammatory drugs (NSAIDs) use, and various symptoms experienced during the race. These findings indicate that a clinical suspicion and measurement of blood sodium concentration remain the only viable means for determining when an ultramarathon runner has EAH.

Despite considerable recent growth in ultramarathon running, little is known about the characteristics of the participants. This work documents demographic characteristics of 161-km ultramarathoners. Surveys were completed by 489 of 674 runners entered in two of the largest 161-km ultramarathons in North America in 2009. Respondents had a mean (± SD) age of 44.5 ± 9.8 years (range 20-72 years) and were generally men (80.2%), married (70.1%), had bachelor's (43.6%) or graduate (37.2%) degrees, and used vitamins and/or supplements (75.3%). They reported 2.8 ± 20.2 days of work or school loss in the previous year from injury or illness. Body mass index (23.4 ± 2.2 and 20.8 ± 1.8 kg/m2 for men and women, respectively) was not associated with age. The findings indicate that 161-km ultramarathon participants are largely well-educated, middle-aged, married men who rarely miss work due to illness or injury, generally use vitamins and/or supplements, and maintain appropriate body mass with aging.

The purpose of this study is to examine the epidemiology and trends of body size in college athletics. Data were coded from available athlete rosters from four division 1 college athletic programs for football, basketball, baseball, and men's/women's tennis for the period of 1950 to the present. Data on 17,500 football, 2,470 basketball, 3,868 baseball, 903 men's tennis, and 765 women's tennis athletes were entered. Increases in height, weight, and body mass index (BMI) were seen for all sports at most positions, but the greatest increases were observed in football offensive and defensive linemen. The largest increases in weight and (BMI) were observed amongst football offensive and defensive linemen, placing them at greatest risk for size-related medical complications. Other college sports exhibit increases in height, weight, and BMI as well, but the rates of increase were not as great.

The purpose of this study was to examine respiratory muscle training (RMT) combined with 9 weeks of resistance and endurance training on rowing performance and cardiopulmonary responses. Twenty-seven rowers (mean ± SD: age = 27 ± 9 years; height = 176.9 ± 10.8 cm; and body mass = 76.1 ± 12.6 kg) were randomly assigned to an inspiratory only (n = 13) or expiratory only (n = 14) training group. Both RMT programs were 3 sets of 10 reps, 6 d/wk in addition to an identical 3 d/wk resistance and 3 d/wk endurance training program. Both groups showed similar improvements in 2000 m rowing performance, cardiorespiratory fitness, strength, and maximum inspiratory (PImax) and expiratory (PEmax) pressures (p < .05). It was concluded that there were no additional benefits of 9 weeks of inspiratory or expiratory RMT on simulated 2000 m rowing performance or cardiopulmonary responses when combined with resistance and endurance training in rowers.

We investigated the effects on body composition in triathletes at the Triple Iron Triathlon Austria in 2006, where athletes had to perform 11.6 km swimming, 540 km cycling, and 126.6 km running within 58 h. In 16 male triathletes, body mass (BM), skinfold thicknesses, and circumferences of extremities were measured before and after the competition in order to calculate body mass index (BMI), percent body fat (%BF), fat mass (FM), and skeletal muscle mass (SM). Body mass, BMI, %BF, FM, and SM decreased statistically significantly (p < 0.01). The loss of BM is associated neither with the decrease of %BF (p > 0.05, r(2)= 0.00) nor with the decrease of SM (p> 0.05, r(2)= 0.06). There is no association between total race time and the loss of BM (r(2) = 0.06), %BF (r(2) = 0.10), and SM (r2 = 0.11). No significant correlation (p > 0.05, r(2)= 0.43) was found between the initial SM and loss of SM.

This study was a prospective epidemiological investigation of upper limb injuries during the Men's Field Hockey Junior World Cup 2009. Three hundred twenty-four players were observed in 58 matches of the tournament. Twenty-eight upper limb-related injuries were documented. The injury incidence was 0.48 per match and 19 per 1,000 match hours. Most injuries were due to contact with the ball, and the left hand was the most commonly injured part. Contusion was the most common type of injury. The odds ratio for hand and wrist injuries in players not wearing gloves was 4.01 (95% CI, 0.52-30.62), and the relative risk of hand and wrist injuries in players wearing gloves was 0.26 (95% CI, 0.03-1.92). Male youth hockey players are at a high risk of upper limb, especially hand and wrist, injuries during major international tournaments and that use of protective gloves can provide significant protection against hand and wrist injuries in the sport.

Heat shock protein 72 (HSP72) is expressed in response to stress and has been demonstrated to follow a diurnal expression pattern within monocytes and is sensitive to changes in core temperature. Numerous studies have shown changes in HSP72 expression within cell lines exposed to hyperbaric conditions. No studies have investigated changes in HSP72 expression in vivo. Six males participated in the study and were exposed to hyperbaric air and hyperbaric oxygen a week apart. Monocyte HSP72 was analyzed by flow cytometry at 09:00, 13:00, 17:00, 21:00 with hyperbaric oxygen or hyperbaric air breathing commencing at 15:00 for 78 min at a pressure of 2.8 ATA. HSP72 under normoxia followed the established trend; however, following the hyperbaric air or oxygen exposure a reduction in detectable HSP72 was observed at 17:00 and 21:00. No changes in core temperature were observed between 13:00 and 21:00 for any condition. The data show that HSP72 expression is impaired following hyperbaric air (HA) exposure, when compared with control or hyperbaric oxygen (HO) exposure.

The purpose of this study was to compare lateral abdominal muscle thickness changes in individuals with and without low back pain (LBP) during an abdominal drawing-in maneuver (ADIM) using ultrasound imaging. Twenty individuals (13 females and 7 males, average age 40.1 ± 13.4) with stabilization classification LBP and 19 controls (10 females and 9 males, average age 30.3 ± 8.7) participated in this study. Bilateral measurements were made using ultrasound imaging to determine changes in thickness of the transversus abdominus (TrA) and external and internal oblique (EO+IO) muscles during an ADIM. There were no significant differences in relaxed muscle thickness values or contraction ratios for the TrA or EO+IO between groups or side. Individuals with stabilization classification LBP demonstrated no difference in lateral abdominal muscle thickness during an ADIM when compared with controls without LBP when using a pressure biofeedback device to monitor stability.

The purpose of this study was to investigate the combined effect of dietary treatment and exercise treatment on abdominal fat distribution and the risk factors for chronic disease in obese Japanese children. The subjects were 33 obese children. The areas of subcutaneous and visceral fat were measured using CT images at the level of the umbilicus. Blood samples were taken to measure risk factors for chronic disease such as triglycerides (TG), total cholesterol (T-Cho), high-density lipoprotein cholesterol (HDL-C), insulin, asparate amino-transferase (AST), alanine aminotransferase (ALT) and uric acid (UA). Supervised exercise treatment at 50% Vo(2)max for about 60 min/day was performed 5 or 7 days/week for 3 months. The dietary treatment was varied with daily calorie intake between 1400 and 1900 kcal depending on the degree of obesity. After dietary treatment combined with exercise treatment, the areas of subcutaneous and visceral fat decreased significantly, and such risk factors as TG, T-Cho, insulin, AST, ALT, and UA were noticeably reduced. These data suggest that dietary treatment combined with exercise treatment in obese children normalizes the distribution of abdominal fat and reduces the risk factors for chronic disease.

We investigated whether the elevated muscle temperature induced by the first bout influenced the VO2 response during a second-bout of heavy exercise. The control conditions were two consecutive 6-min leg cycling bouts (work rate: Δ50% between LT and VO2max) separated by a 6-min baseline at 20 W (L1-ex to L2-ex). In the experimental conditions prior to the main bout (H2-ex), the diathermic warming to the front thigh was substituted for the first-bout. The VO2 response for the second bout was significantly accelerated compared with the first bout (mean ± SD of the τ by monoexponential fitting: L1-ex: 53.8 ± 11.6, L2-ex: 38.7 ± 7.9 s, P < 0.05). The diathermic warm-up, however, could not accelerate VO2 response for subsequent supra-LT leg exercise (τ for H2-ex: 52.3 ± 7.7 s). It was concluded that the facilitation of [VO2 response during supra-LT exercise after prior heavy exercise does not seem to be caused by increased muscle temperature per se and its related factors.

This study investigated the effects of various shoe features and surfaces on step time variability and pelvis accelerations (RMS) during walking in six younger and 22 older adults. Participants walked at a self-selected speed in five shoe conditions (standard, elevated heel, soft sole, hard sole, and high collar) on two surfaces: level and irregular. Results showed an age-related reduction in step time variability on the irregular surface and increased medio-lateral (ML) acceleration RMS in older people walking on the irregular versus the level surface. When wearing the elevated heel shoes, both young and old participants displayed significant reductions in pelvis ML accelerations, suggesting a compensatory strategy to counteract for lateral instability resulting from heel elevation. Overall, the findings demonstrate that older people are less able than younger ones to meet the stepping adaptability required for negotiating an irregular surface and, as a possible consequence, have more difficulty maintaining frontal plane stability on such a surface.

The purpose of this study was to establish the effects of four variables on the results obtained for a Wingate Anaerobic Test (WAnT). This study used a 30 second WAnT and compared data collection and analysed in different ways in order to form conclusions as to the relative importance of the variables on the results. Data was collected simultaneously by a commercially available software correction system manufactured by Cranlea Ltd., (Birmingham, England) system and an alternative method of data collection which involves the direct measurement of the flywheel velocity and the brake force. Data was compared using a design of experiments technique, the Taguchi method. Four variables were examined - flywheel speed, braking force, moment of inertia of the flywheel, and time intervals over which the work and power were calculated. The choice of time interval was identified as the most influential variable on the results. While the other factors have an influence on the results, the decreased time interval over which the data is averaged gave 9.8% increase in work done, 40.75% increase in peak power and 13.1% increase in mean power.

When assessing the fitness levels of athletes, body composition is usually estimated, as it may play a role in athletic performance. Therefore, the purpose of this study was to determine the validity of bioelectrical impedance analysis (BIA) and skinfold (SKF) methods compared with dual-energy X-ray absorptiometry (DXA) for estimating percent body fat (%BF) in Division 1 collegiate baseball players (n = 35). The results of this study indicate that the field methods investigated were not valid compared with DXA for estimating %BF. In conclusion, this study does not support the use of the TBF-350, HBF-306, HBF-500, or SKF thickness for estimating %BF in collegiate baseball players. The reliability of these BIA devices remains unknown; therefore, it is currently uncertain if they may be used to track changes over time.

This study examined the kinematic differences between subjects who had a history of chronic Achilles tendon (AT) injury and matched controls during running. Eleven subjects from each group ran barefoot (BF) and shod at self-selected speeds on a treadmill. Three-dimensional angles describing rearfoot and lower limb motion were calculated throughout stance. Five footfalls were obtained for each subject and condition. Pairwise comparisons revealed greater eversion, ankle dorsiflexion and less leg abduction during stance in the AT group compared with controls. Running kinematics were exaggerated in shod compared with BF conditions, as expected from previous research. The differences between conditions were more exaggerated in AT subjects compared with control subjects. Further analysis using a curve-based approach is recommended.

This study compared the biomechanics of jump landing tasks used in ACL research. Twenty-seven female subjects performed a drop landing (DL), a drop landing with a vertical jump (DVJ), and a forward jump landing with a vertical jump (FVJ). We hypothesized that as one progressed from the drop landing through the forward-vertical jump that the kinematic and kinetic demands would increase, with progressively increasing knee and hip forces, moments, and angles on landing. Separate repeated-measures ANOVAs were performed. The FVJ had the highest peak anterior tibial shear force (p < 0.001), hip flexion angle (p < 0.001), knee flexion moment (p < 0.001), and knee valgus moment (p < 0.001). The DL had the smallest knee flexion angle (p = 0.001) and hip flexion angle (p < 0.001), while the DVJ had the lowest knee valgus moment (p < 0.001). These results indicate that seemingly minor variations between jump landing tasks may influence landing biomechanics. Caution should be used when comparing studies using different tasks.

The objective of this study was to verify whether proprioception is affected in individuals with ACL-deficient knees and good functional and muscular performances. Eleven subjects with ACL injury and 11 controls participated in the study. Functional performance was assessed using the Cincinnati Knee Rating System (CKRS), hop index, and figure-eight ratio. An isokinetic test was done to evaluate muscular performance. Proprioception was evaluated through position, sense and threshold tests. Analyses of variance were used for data analysis. The injured subjects scored significantly lower in the CKRS (p = 0.001). No statistically significant differences were found in the hop index, in the figure-eight ratio, or in peak torque. There were no statistically significant differences in proprioception bettween groups and between legs. These results indicated that the individuals evaluated in this study with ACL injury and good functional and muscular performance did not have proprioceptive deficits, suggesting that the ligament mechanoreceptors, in some cases, might not contribute relevantly to proprioception.

Prevention strategies have been developed based on existing knowledge in an attempt to alter neuromuscular control and lower extremity biomechanics in order to reduce anterior cruciate ligament (ACL) injury rates. These strategies have included different training programs ranging from injury education to multicomponent training. Many training programs have been demonstrated as resulting in altered lower extremity movement patterns. The effects of current training programs on ACL injury rate, however, are inconsistent. This review was focused on the effects of current ACL injury training programs on neuromuscular risk factors and ACL injury rate. Recommendations were made based on the available evidence for clinicians and coaches to implement ACL injury prevention programs.

The purpose of this systematic review was to assess the efficacy of training interventions aimed to prevent and to reduce anterior cruciate ligament injury (ACLI) rates in team sport players. We searched MEDLINE from January 1991 to July 2011 using the terms knee, ACL, anterior cruciate ligament, injury, prevention, training, exercise, and intervention. Nine out of 708 articles met the inclusion criteria and were independently rated by two reviewers using the McMaster Occupational Therapy Evidence-Based Practice Research Group scale. Consensus scores ranged from 3 to 8 out of 10. Seven out of nine studies demonstrated that training interventions have a preventive effect on ACLI. Collectively, the studies indicate there is moderate evidence to support the use of multifaceted training interventions, which consisted of stretching, proprioception, strength, plyometric and agility drills with additional verbal and/or visual feedback on proper landing technique to decrease the rate of ACLIs in team sport female athletes, while the paucity of data preclude any conclusions for male athletes.

The anterior cruciate ligament (ACL) injury is one of the most common injuries in sports. ACL injuries are not only costly from financial and health services consumption standpoints, but also can have devastating consequences on patients' activity levels and quality of life. Tremendous efforts have been made over the past two decades toward the goal of preventing ACL injuries. A substantial number of studies have been performed to determine the characteristics of ACL injury events, identify risk factors for ACL injury, and develop prevention strategies. The purpose of this review was to objectively summarize the current literature regarding the characteristics of ACL injury, ACL loading mechanisms, and risk factors for injury to provide a comprehensive understanding of the current state of research and how our current level of knowledge may inform clinical practice in this area.

Accurate documentation of injury incidence is critical for study of injury risk factors and prevention. Comparisons of published incidences of anterior cruciate ligament (ACL) injuries and surgical reconstructions are difficult, however, because of the variations in units. Some studies report absolute time-based denominators (such as annual incidence or incidence per 100,000 person years), whereas others report exposure-based denominators (such as incidence per 1,000 player hours or athlete exposures). We converted exposure-based units into annual incidences to compare various studies. National population studies show annual incidence rates of up to 0.05% per person per year in Australia. Professional athletes in basketball, soccer, and the other football codes report an annual incidence of 0.15%-3.7% in studies with at least a moderate sample size. Annual ACL incidence in amateur sporting groups was generally higher than the entire population but lower than among professional athletes. Converting incidence rates to annual units allowed better comparisons to be made between population rates across different studies.

The purposes of this study are to determine the optimal cadence of individuals and to subsequently determine the effectiveness of the augmented feedback training program on cadence technique modification. Eighteen physically active subjects, 14 males and 4 females who are aged 18 to 23, were the volunteer subjects of the study. Each subject performed three sessions of exercise in a random order at the cadences of 60, 70, and 80 revolutions per minute (rpm). Myoelectric signals from the vastus lateralis muscle were recorded during the criterion exercise to determine the optimal cadence of individual subjects. They also participated in a 10-day cadence training program, during which the augmented feedback group was provided with cadence information, while the control group trained without the feedback. The time percentage of cadence error that deviated from the optimal cadence in the augmented feedback group was reduced significantly (p < 0.05) after 10 days of training, and the same result was shown in the retention test.

Measurement of scapular kinematics is an important component in the assessment of shoulder function; however, repeatability of these measurements has not been established. The purpose of this study, therefore, was to determine the repeatability of scapular rotation measures for different humeral elevation planes between trials, sessions, and days. Three-dimensional scapular rotations were collected using an electromagnetic tracking system in three planes of humeral elevation. Coefficient of multiple correlation (CMC) values were calculated between trials, sessions, and days for curves of scapular rotations. CMC values were compared with repeated measures analysis of variance (ANOVAs) and Tukey's post-hoc procedures. Tests of simple main effects were performed for significant interaction effects. Our results suggest that scapular rotation measures are repeatable between trials within the same testing session, but less repeatable between testing sessions and days. Sagittal plane elevation consistently yielded the highest CMC values for all scapular rotations. These results suggest sagittal plane elevation should be considered to evaluate differences in scapular rotations.

This longitudinal study extends the previous research on low participation rates and high dropout rates in phase III cardiac rehabilitation (CR) exercise programmes. It examines the correlates of motivation and participation 6 months after inpatient phase II CR (T1) and the predictors of dropout 6 months later (T2) using the health action process approach (HAPA). Risk perception, outcome expectancies, self-efficacy, intention (at T1), and participation (at T1 and T2) in relation to phase III CR programmes was assessed in 456 patients. Based on intention and participation at T1, patients were classified as nonintenders (56%), intenders (13%), or actors (31%). Group differences were confirmed in outcome expectancies and self-efficacy. By T2, 21% of T1 actors had dropped out. Dropouts and maintainers differed in intention and self-efficacy (at T1). Results are in line with the HAPA and suggest a perspective for tailoring motivational counselling to improve participation in phase III CR programmes.

The aim of this study was to compare the effect of concentric with eccentric muscle actions on the resulting level of damage to connective tissues by urinary concentration of hydroxyproline. Twenty-one male volunteers were divided into control group (CG), experimental concentric group (ECG), and experimental eccentric group (EEG). The measures of hydroxyproline were performed at three times: pretest, fourth week, and posttest. Biceps curl and chest press exercises also were performed with three sets of 10 repetitions two times per week for both experimental groups. Analysis of variance (ANOVA) showed a significant difference between pretest of the CG and pretest of the ECG (p = 0.002), and between pretest and posttest for the EEG (p = 0.029). Therefore, this study concluded that the level of damage to the connective tissue is greater when exercises involving eccentric muscle actions are performed. The continuity of training, however might reduce this damage.

The purpose of this study was to investigate the effects of antagonist passive static stretching (AS) during the inter-set rest period on repetition performance and muscle activation. Ten trained men (22.4 ± 0.9 years) participated in this study. Two protocols were adopted: Passive recovery (PR) - three sets to repetition failure were performed for the seated row (SR) with two-minute rest interval between sets without pre-exercise stretching; AS - forty seconds of stretching was applied to pectoralis major prior to each set of SR. Significant increases in the number of repetitions were noted under AS compared with PR (p < 0.05). Significant increases on latissimus dorsi (p = 0.002) and biceps brachii (p = 0.001) muscle activity were noted inter-sets under the AS compared with the PR condition. Therefore, the AS adopted during the inter-set rest period may enhance repetition performance and activation of agonist muscles in an acute manner.

The purpose of this study was to clarify the activation patterns among knee flexor muscles during knee flexion exercises by electromyography (EMG) and muscle functional magnetic resonance imaging (mfMRI). Seven male volunteers performed knee flexion exercises with each unilateral limb at 120% of 1 repetition of maximum (1RM) and 50% of 1RM. EMG activity was recorded for the biceps femoris long head, semitendinosus (ST), semimembranosus (SM), and gracilis (G) muscles; mfMRI T2 values in the same muscles were measured at rest and immediately after exercise. The study found that EMG of the ST and G was significantly higher than that of the SM during the exercises at 120% 1RM. T2 value changes in the ST and G were significantly higher than in the biceps femoris long head (BFlh) and SM in both exercises [corrected].It was concluded that the activation patterns among knee flexor muscles during knee flexion were nonuniform for the respective muscles.

This study explored the trunk and lower limb muscle activity of 15 males during unilateral hockey bag carriage of 10%, 20%, and 30% of one's body weight (BW) compared with without a load during walking. The electromyography (EMG) activities of the left and right erector spinae, rectus abdominis, gluteus maximus, rectus femoris, vastus medialis, biceps femoris, semitendinosus, and the medial gastrocnemius were studied. A 2-way repeated measures analysis of variance (ANOVA) was used to examine the differences between the load weight and muscle side. Results showed significant increase in peak EMG and iEMG in the carrying side vastus medialis, rectus abdominis, semitendinosus, and gastrocnemii (p < 0.05) at the 30% BW load. The noncarrying side showed a greater peak EMG in the semitendinosus and rectus femoris at the 30% BW load when compared with the carrying side (p < 0.05). It was concluded that unilateral hockey bag carriage is similar to both backpack and side-pack carriage styles.

The aim of this study was to investigate upper body muscle activity during a 30 s Wingate test. Eighteen physically active participants performed a Wingate test while muscle activity was recorded from the brachioradialis (BR), biceps brachii (BB), triceps brachii (TB) and upper trapezius (UT). Measurements were obtained at rest, during a function maximal contraction (FMC) and during the 30 s Wingate test, whilst participants were positioned in a seated position on the cycle ergometer. All muscles were significantly active for the duration of the test. When normalized as a %FMC no differences in activity were found between muscles. Across the 30 s, power output was found to significantly decrease, whereas no changes were found in upper body muscle activity. All muscles investigated were active during the Wingate test and therefore confirmed previous findings that the upper body significantly contributes to power profiles obtained during high intensity cycle ergometry in addition to its role in stabilizing the body.

The main aim of this study was to examine the effects of 4 weeks of glucosamine administration on the functional ability and the degree of pain intensity in competitive male athletes after acute knee injury. This study was a randomized, double-blind parallel trial of glucosamine (1500 mg per day) or a placebo for 28 days, utilising 106 patients with an acute knee injury. Pain and functional ability were evaluated at the beginning of the study and at 7, 14, 21, and 28 days after starting treatment. Pain intensity at rest and while walking was assessed using a visual analog scale. Passive knee flexibility (flexion and extension) of the injured limb was measured using a modified goniometer, and the degree of knee swelling was measured and compared with the noninjured limb. No significant difference was found between the glucosamine, and placebo group in mean pain intensity scores for resting and walking, and degree of knee swelling at the 7-day, 14-day, 21-day, and 28-day assessment. There was no significant difference between passive knee flexibility at the 7-day, 14-day, and 21-day assessment. After 28 days of treatment the patients from the glucosamine group demonstrated significant improvement in knee flexion and extension as compared with the placebo group.

Rooibos tea contains polyphenol antioxidants, including flavonoids and phenolic acids that are potent free radical scavengers and has purported benefits for accelerated rehydration. The objective was to evaluate the effects of three different drinks (rooibos tea, bottled water, and a carbohydrate beverage) on blood and urinary markers of hydration after acute dehydration in collegiate wrestlers. Twenty-three athletes were recruited and followed a randomized, cross-over design with three different study arms comparing the effectiveness of rooibos tea, carbohydrate beverage (6% or 60 grams l(-1)), or bottled water (placebo) in promoting rehydration after a 3% reduction in body mass. Urine specific gravity (U(sg)) urine (U(osm)) and plasma osmolarity (P(osm)), and plasma volume were measured pre- and post dehydration and at 1-h after rehydration. Statistical analyses utilized a 3 (conditions) x 3 (times) repeated measures analysis of variance to test main effects. Significant interaction effects were found for P(osm) and U(osm), both of which remained below basleline after 1-h rehydration in the rooibos tea and water trials. No significant interaction effects were found for either urine U(sg) or plasma volume shift. The findings of this study demonstrate that rooibos tea was no more effective in promoting rehydration than plain water, with significant changes being found for P(osm) and U(osm) in the carbohydrate/electrolyte solution, in collegiate wrestlers after a 3% reduction in body mass and a rehydration period of 1-h when consuming 100% of their body weight loss.

This study aimed to investigate the acute effect of static stretching (SS) on peripheral vascular tonus and to clarify the effect of SS on systemic circulation. Twenty healthy young male volunteers performed a 1-min SS motion of the right triceps surae muscle, repeated five times. The peripheral vascular tonus (|d/a| ratio) was obtained using second derivatives of the photoplethysmogram readings before, during, and after SS. Heart rate and blood pressure (BP) were also measured. The |d/a| ratio and BP were transiently, but significantly, elevated during SS and returned to baseline immediately after SS. Furthermore, we observed a significant correlation between the amount of change in the |d/a| ratio and the ankle range of motion during SS (r = 0.793 to 0.832, P = 0.01). These responses may be caused by mechanical stress during SS.

The purpose of the study was to evaluate the prevalence of acute kidney injury (AKI) during a multi-stage ultramarathon foot race. A prospective observational study was taken during the Gobi 2008; Sahara 2008; and Namibia 2009 RacingThePlanet 7-day, 6-stage, 150-mile foot ultramarathons. Blood was analyzed before, and immediately after stage 1 (25 miles), 3 (75 miles), and 5 (140 miles). Creatinine (Cr), glomerular filtration rate (GFR), and incidence of AKI were calculated and defined by RIFLE criteria. Thirty participants (76% male, mean age 40 + 11 years) were enrolled. There were significant declines in GFR after each stage compared with the pre-race baseline (p < 0.001), with the majority of participants (55-80%) incurring AKI. The majority of study participants encountered significant renal impairment; however, no apparent cumulative effect was observed, with resolution of renal function to near baseline levels between stages.

This study investigated the effect of stretching on sprint performance. Ten trained male subjects (age 22 +/- 2.3 yrs; body mass 77.1 +/- 6.9 kg; height 179 +/- 5.5 cm) were randomly assigned to "Rest" and "Stretch" conditions. A low intensity 5 min running warm-up was followed by either 12 min of inactivity (Rest) or lower-limb stretches (Stretch). Subjects walked for 60 s before completing three maximal effort 40 m sprint trials. There were no statistically significant differences in measures of sprint performance between conditions (p > 0.05); however, there was a significant correlation between baseline sit-and-reach scores and mean change in mean velocity between conditions (r = -0.68; p = 0.03). There was a tendency for stretching to negatively effect sprint performance in subjects with comparatively high baseline flexibility. An acute bout of stretching did not exert a significant effect on sprint performance under prescribed conditions.

Arterial stiffness scores over a 5-h period following a 2-h run were measured in trained males (N = 8, age 39.3 ± 2.3 y) and females (N = 8, 35.8 ± 2.8 y). Subjects reported for two lab sessions (randomized, crossover design) from 7:30 am to 4:15 pm, separated by 1-2 weeks, and either rested or ran for 2 h on a treadmill at 75% VO(2max) from 9:15 to 11:15 am. Augmentation index standardized to a heart rate of 75 bpm (AIx75), and carotid to femoral pulse wave velocity (PWV), were measured by applanation tonometry. Significant interaction effects were measured for AIx75 (P = 0.039) and PWV (P = 0.020), and compared with the rest condition, female runners experienced decreased AIx75 from 11:45 am to 3:15 pm, and in PWV at 11:45 am and 12:15 pm, in contrast to no change in the male runners. These data support a notable gender difference in arterial stiffness following a 2-h bout of running.

This study examined the acute effects of a single dose of an antioxidant (AO; Lactaway® containing pycnogenol) on time to fatigue (TTF). Nine trained cyclists [mean ± SD age 35 ± 10 yrs; body mass 71.6 ± 10.2 kg; VO2 peak 63 ± 11 ml/kg/min] performed on two separate occasions a continuous protocol of 5 min at 50% of peak power output (PPO), 8 min at 70% of PPO, and then cycled to fatigue at 95% PPO. Four hours prior to the exercise protocol, the subjects consumed the supplement or a placebo (counterbalanced, double blind protocol). Cyclists, on average, rode for 80 s more in the Lactaway trial than they did in the placebo trial. There was considerable evidence (chances ≥94.5%) for substantial positive treatment effects for TTF and the other performance-related variables (excluding [BLa] at 95% PPO). Other studies are necessary to confirm these results and identify the mechanisms underlying the observed effects.

There is a paucity of research examining the influence of acute exercise on pulse wave velocity (PWV) and oxidative stress. The purpose of this study was to examine the effects of acute moderate aerobic exercise on PWV and oxidative stress in healthy males. Eight apparently healthy males (age 23.6 ± 2.8 yrs; stature 181.4 ± 8.1 cm; weight 83.4 ± 16.2 kg; all data mean ±SD) participated in a randomized crossover design consisting of (i) a one hour bout of moderate aerobic exercise and (ii) a control trial of one hour rest. Pre- and post-exercise blood samples were drawn for the determination of lipid hydroperoxides (LOOHs) and lipid-soluble antioxidants (lycopene, retinol, and β-carotene). Exercise had no effect on stiffness and LOOHs (P > 0.05). Retinol and lycopene were increased following exercise (P < 0.05). These findings suggest that acute moderate exercise has no effect on PWV and LOOHs, but it can increase systemic antioxidants, which may be of benefit to health.

Six men and six women (24.4 ± 6.4 years) who had been diagnosed with T1D for 7.3 ± 6.8 years volunteered for the study. Three RT sessions were repeated with the same experimental approach with randomized load percentages. Blood glucose measurements were performed at rest, after warm-up, immediately after the last set of each exercise, and 10, 20, and 30 minutes after the exercise session. Significant decreases from rest for blood glucose concentration in each intensity vs. post warm-up, immediately post exercise session, and 10, 20 and 30 minutes after total training session were observed. Effect size (ES) results for the 60 and 80% of 1RM intensities demonstrated large magnitudes. The three intensities investigated promoted a reduction in blood glucose levels and therefore can be recommended for diabetic patients. In addition, the moderate and high intensities appear to lower blood glucose levels to a greater extent than the low intensity.

Dehydration has been shown to augment cellular stress. Glycerol hyperhydration can delay dehydration, which may decrease the level of pre- and post-exercise oxidative stress. This study aimed to compare the effects of glycerol (G) or water (W) hyperhydration with no hyperhydration (C) on oxidative stress, thermoregulation, and cycle performance. Seven trained males consumed 1.2 g of glycerol·kg(-1) body mass (BM) in 26 ml·kg(-1) BM water or equal volume water to achieve hyperhydration followed by a 90 min time trial. Total glutathione increased post exercise (PE) in all trials (p < 0.01), while oxidized glutathione (p < 0.05) and protein carbonyl concentrations (p < 0.001) were increased PE for the C trial only. Mean body temperature and heart rate increased with exercise but were not different between interventions. Total distance covered and power outputs were not different between interventions. Fluid intake attenuated oxidative stress but did not enhance thermoregulation or performance.

This study investigated and compared the effects of an eight-week program of whole body vibration combined with counter-movement jumping (WBV + CMJ) or counter-movement jumping (CMJ) alone on players. Twenty-four men's volleyball players of league A or B were randomized to the WBV + CMJ or CMJ groups (n = 12 and 12; mean [SD] age of 21.4 [2.2] and 21.7 [2.2] y; height of 175.6 [4.6] and 177.6 [3.9] cm; and weight, 69.9 [12.8] and 70.5 [10.7] kg, respectively). The pre- and post-training values of the following measurements were compared: H-reflex, first volitional (V)-wave, rate of electromyography rise (RER) in the triceps surae and absolute rate of force development (RFD) in plantarflexion and vertical jump height. After training, the WBV + CMJ group exhibited increases in H reflexes (p = 0.029 and <0.001); V-wave (p < 0.001); RER (p = 0.003 and <0.001); jump height (p < 0.001); and RFD (p = 0.006 and <0.001). The post-training values of V wave (p = 0.006) and RFD at 0-50 (p = 0.009) and 0-200 ms (p = 0.008) in the WBV + CMJ group were greater than those in the CMJ group. This study shows that a combination of WBV and power exercise could impact neural adaptation and leads to greater fast force capacity than power exercise alone in male players.

The purpose of this study was to explore the gait pattern and metabolic responses of walking with negative heel shoes as compared to walking with normal shoes. Nineteen female subjects were recruited, of whom 13 (aged 23.08 ± 3.9 years, body weight 50.18 ± 5.3 kg, and body height 1.63 ± 0.05 m) participated in the gait pattern study, and 6 (age 32.8 ± 6.6 years, body weight 58.3 ± 5.8 kg, and body height 1.64 ± 0.01 m) in the metabolic study. In the gait pattern study, movement kinematics and kinetic data were obtained by video analysis and force platform measurement during the process of walking at a constant speed of 1.33 m/s on a treadmill and over ground, respectively. In the metabolic study, heart rate and oxygen consumption were monitored during treadmill walking. The results showed that there was a significant difference between walking on a treadmill with negative heel shoes and walking with normal shoes, in terms of stride cycle time, cadence, stride length, and angles of the ankle, knee, and hip joints. Differences also were found with the maximum and minimum ground reaction forces and their occurrence times. Metabolically, heart rate and oxygen consumption showed a significant difference. In conclusion, walking with negative heel shoes induced significant changes in gait patterns, ground reaction forces, and energy consumption.

Adaptations in aerobic exercise responses as well as the relationship between aerobic exercise responses and running performance were examined in a group of previously trained adolescent runners (n = 9; 15.9 +/- 1.0 years) over the course of a competitive cross-country season. Running economy (RE), submaximal blood lactate concentration [BLa] and VO2max were assessed before and immediately after the season. Five-km race time improved (P < 0.05) from 18.68 +/- 1.10 min at the beginning of the season to 18.16 +/- 1.11 min at the end of the season. Significant increases were observed in peak VO2 (61.6 +/- 3.5 to 65.3 +/- 2.9 mL x kg(-1) x min(-1)) and graded exercise test time (11.32 +/- 1.56 to 12.22 +/- 0.79 min). There was a tendency for RE (P = 0.051) to worsen slightly and for [BLa] (P = 0. 057) to decline as a result of training. At the beginning of the season submaximal [BLa] at 14 km x hr(-1) (r = 0.86) and graded exercise test time (r = -0.87) were significantly related to 5-km time. At the end of the season, RE (r = 0.78) and [BLa] (r = 0.77) at 14 km x hr(-1) and graded exercise test time (r = -0.69) were significantly related to race time. In this well-trained group of runners, further training during the cross-country season increased peak VO2 and improved race time. Submaximal [BLa] and graded exercise test time appear to be the most robust predictors of performance, while RE became a significant predictor of race time at the end of the season.

The study investigated the effects of low-intensity exercise on muscular fitness when combined with vascular occlusion. Nineteen college male and female students performed two sets of a 5-min step exercise using a 12-inch bench three times per week for 5 weeks. During the step exercise, blood flow to one leg was restricted (vascular occlusion) with a blood pressure cuff, while the other leg was not occluded. Muscular strength of the occluded leg was significantly increased over the nonoccluded leg (p < 0. 05). Muscular endurance and muscle mass were improved after 5 weeks of training (p < 0.05); however, the changes between the two legs were not significantly different (p > 0.05). Exercise with vascular occlusion has the potential to be an alternative form of training to promote muscular strength.

The purposes of this study were to examine effects of a season of training on aerobic performance in cross-country distance runners and to analyze the training using subjective and objective techniques. Subjects averaged 184 minutes of running per week, with 45%, 24%, and 31% occurring in zones below, near, and above the heart rate (HR) corresponding to ventilatory threshold (VT(HR)), respectively (Zone 1: HR > 15 bpm below VT(HR); Zone 2: HR between Zone 1 and VT(HR); Zone 3: HR > VT(HR)). Maximal oxygen uptake (VO(2 max)) increased by 5.1%, 5-km race time by 46 seconds (3.7%), and 2-km time trial performance by 54 seconds (10.7%) from pre- to postseason. Results are similar to previous research demonstrating that short-term (< 3 months) endurance training elicits improvements in various physiological parameters. Findings were not consistent with previous research that suggests a discrepancy may exist between the runners' perceptions and the physiological effects of their training.

The purpose of this study was to further examine the influence of hand-grip strength on power profiles and blood lactate values during high-intensity cycle ergometry. Fifteen male subjects each completed a 20-second cycle ergometer test twice, in a random manner, using two protocols, with a hand grip (WG), and without hand grip (WOHG). Hand-grip strength was quantified prior to exercise using a hand-grip dynamometer. Capillary (earlobe) blood was collected at rest, immediately following exercise, and 5 minutes postexercise. In the WG protocol, mean (+/-SD) blood lactate concentrations were 1.11 +/- 0.7 mmol.l( -1), 3.68 +/- 1.2 mmol.l( -1), and 8.14 +/- 1.3 mmol.l( -1), respectively. During the WOHG protocol, blood lactate values recorded were 0.99 +/- 0.9 mmol.l( -1), 3.68 +/- 1.1 mmol.l( -1), and 6.62 +/- 0.9 mmol.l( -1), respectively. Differences in lactate concentrations were found (P < 0.05) from rest to 5 minutes postexercise for both groups. Differences in concentrations also were observed between groups at the 5-minutes postexercise stage. Peak power output and fatigue index values also were greater using the WG protocol (792 +/- 73 W vs. 624 +/- 66 W; 38 +/- 6 vs. 24 +/- 8 W respectively; P< 0.05). No differences were recorded for mean power output (MPO) or work done (WD) between experimental conditions. These findings suggest that the performance of traditional style leg cycle ergometry is influenced by a muscular contribution from the upper body and by upper body strength.

It is widely acknowledged that the importance of sound theoretical guidance is essential to any academic discipline. A common recommendation within the adherence literature related to sport injury rehabilitation has been the need to establish clear theoretical frameworks to guide research and practice. As such, an increasing amount of literature has employed conceptual models that include protection motivation theory, health action process approach, cognitive appraisal models, and attribution theory. Therefore, the purpose of this review is to critically evaluate these contemporary theoretical approaches that have been utilised within the sport injury rehabilitation adherence literature. Alongside this, practical implications emerging from this research base are outlined and future recommendations are suggested that may be of benefit to sports medicine practitioners and researchers alike.

Our objective is to examine the role of planning skills for translating intentions into physical activity via planning cognitions. A study with 534 adolescents was conducted. Over 4 weeks, intention, planning cognitions (prospective anticipation of when, where, and how to perform activities), planning skills (successful past planning experiences), and physical activity were assessed. The results were that skills correlated with intention, planning cognitions, and subsequent physical activity. Planning cognitions were found to mediate the intention–behavior relation, whereas skills moderated the mediating role of planning cognitions: If students reported high skills, they were more likely to translate their intentions into plans and behavior. We conclude that having more skills makes it more likely that adolescents successfully translate their intentions into plans. Promotion of physical activity should improve planning cognitions but also planning skills. Only with planning cognitions and skills might adolescents better be able to act in accordance with their intentions and perform physical activity.