Effective pedal forces throughout the entire crank cycle during cycling at various power outputs (a) and cadences (b). 0° crank angle refers to top dead centre. Figure reproduced by permission of the publisher Taylor & Francis Ltd , from Sanderson DJ, Hennig EM and Black AH. The influence of cadence and power output on force application and in-shoe pressure distribution during cycling by competitive and recreational cyclists. J of Sports Sci 2000. 61 .
Relationship between peak crank torque, crank velocity (i.e. cadence) and power output during short duration (<10s) maximal cycling in two separate subjects (solid and 51 dashed lines). Figure used with permission from J Appl Physiol. 
Muscular, non-muscular and total pedal forces while cycling at 120W and at 60, 75, 90, 105 and 120rpm. Reprinted from: J Biomech, Vol.32, Neptune RR and Hertzog W. The association between negative muscle work and pedaling rate, pp.1051-1026, 1999, with 54 permission from Elsevier. . 
Diagram demonstrating the direction and magnitude of pedal forces throughout a typical clockwise pedal cycle. Note counterproductive (negative) pedal forces during the upward phase of the pedal cycle. Reprinted, with permission, from J.P. Broker, 2003, Cycling Biomechanics: Road and Mountain. In: High-Tech Cycling: The Science of Riding Faster, edited by E.R. Burke, 2 nd ed. (Champaign, IL: Human Kinetics, 125, figure 5.4. 11 .
Changes in muscle blood flow (circle), muscle oxygenation (square), pedal forces (triangle), knee angle and rectified electromyography (EMG) throughout a pedal cycle. 0° crank angle refers to top dead centre. Figure reprinted with permission from Lippincott Williams & Wilkens for Takaishi T, Sugiura T, Katayama K, et al. Changes in blood volume 
Cadence or pedal rate is widely accepted as an important factor influencing economy of motion, power output, perceived exertion and the development of fatigue during cycling. As a result, the cadence selected by a cyclist's could have a significant influence on their performance. Despite this, the cadence that optimises performance during an individual cycling task is currently unclear. The purpose of this review therefore was to examine the relevant literature surrounding cycling cadence in order provide a greater understanding of how different cadences might optimise cycling performance. Based on research to date, it would appear that relatively high pedal rates (100-120rpm) improve sprint cycling performance, since muscle force and neuromuscular fatigue are reduced, and cycling power output maximised at such pedal rates. However, extremely high cadences increase the metabolic cost of cycling. Therefore prolonged cycling (i.e. road time trials) may benefit from a slightly reduced cadence (~90-100rpm). During ultra-endurance cycling (i.e. >4h), performance might be improved through the use of a relatively low cadence (70-90rpm), since lower cadences have been shown to improve cycling economy and lower energy demands. However, such low cadences are known to increase the pedal forces necessary to maintain a given power output. Future research is needed to examine the multitude of factors known to influence optimal cycling cadence (i.e. economy, power output and fatigue development) in order to confirm the range of cadences that are optimal during specific cycling tasks.
Biokinetic Swim Bench It provides acceleration settings from 1 (1.44 º/s 2 ) to 9 (3.07 º/s 2  
Calisthenics and resistance training
Percentage of change in peak-and mean-work in exercise (EG) and control group (* = p<0.05). (PPW=peak-prone work, PSW=peak-supine work, MW=mean work)
Background: The decrease in muscle mass and muscular strength and the increase in total body weight have significant implications for the health and functioning of postmenopausal women. Exercising in water has become increasingly popular as a means of delaying the physiological decline associated with age in middle-aged and older women. Research question: Is a 12-month aerobic and resistance water training program in a shallow pool effective in increasing muscle strength and decreasing total body weight in postmenopausal women? Type of study: Randomised controlled study. Methods: Thirty-eight subjects were randomly assigned to an exercise group (EG; n = 21) and a control group (CG; n = 17). The exercise group enrolled in a systematic aerobic and resistance training programme for 12 months performed at a frequency of 2 sessions per week, 45 minutes per session. Upper-extremity biokinetic strength and body mass index (BMI) were measured before and after the intervention. CG participants were physically active. Results: EG participants improved significantly (p ≤ 0.05) in mean force (MF: 7.92%), mean power (MP: 9.08%) and mean work (MW: 9.3%). Mean stroke length decreased significantly (p ≤ 0.05) in EG (-5.68%) and in CG (-11.5%). BMI was also significantly decreased (p ≤0.05) in EG participants (-2.75%). Conclusions: These results indicate that training in a shallow pool has significant implications for improving upper extremity muscular strength and total body weight in postmenopausal women.
Background: The identification of the variables that are able to predict swimming performance is one of the main purposes of the "swimming science" community. Research question: The aims of the study were: (i) to compare the anthropometric and physiological profiles of 100m and 200m front crawl swimmers and; (ii) to identify anthropometric and physiological variables that account for the prediction of the swimming performance at the 100m and 200m front crawl events. Methods: Twenty-six male swimmers were divided in two groups (12 for 100m group and 14 to 200m group). The swimmers' personal best performance for the 100m and the 200m front crawl was converted to FINA points. The subjects performed a graded swimming test and an all-out test (100 or 200m maximal swims) in different days, in which physiological measures were evaluated. Forward step-by-step linear regression models were computed to predict swimming performance. The subjects' performances (season best and all-out test) were taken as dependent variables. The age, physiological and anthropometric measures were selected as independent variables. Results: Anthropometric and physiological profiles of 100 and 200m swimmers are different and the mean oxygen uptake during exercise combined with training experience may explain 200m front crawl best season performance with a high precision (≈2% error). The models computed were able to predict from 44 % (i.e. 200m all-out bout) to 61 % (i.e. 200m season best) swimming performance. Predictive power of the models was less accurate in the 100m event (error > 10%). Conclusions: The authors conclude that the extent to which the physiological and anthropometric variables combine to predict performance probable is group-specific.
Highest heart rate (HR) per acclimation day No significant differences in T re were observed between groups (p = 0.321). T re significantly decreased across time (main effect) (p = 0.017) (Figure 2). However, post-hoc 
Background: The influence of age on heat acclimation responses among aerobically fit males across a 14 day high intensity running protocol was assessed. Research question: Will young and middle-aged males with similar VO2max, weekly running distance and body composition respond similarly to continuous, high intensity exercise-heat acclimation? Hypothesis: Young and middle-aged males would respond similarly and fully acclimate within 14 days. Study type: Non-randomised comparative. Methods: 9 young (20.4 +± 2.4 years; 57.1 ± 3.8 ml·kg -1·min -1), 7 middle-aged (44.6 ± 4.5 years; 55.2 ± 6.3 ml·kg -1·min -1 pre-acclimation) male runners participated. Protocol: 30 minute runs daily at 75% O2max in a hot, moderately humid (35°C, 35% RH) environment Outcome measures: resting plasma volume % change (PV), rectal temperature (Tre), heart rate (HR), sweat loss (SL), perceived exertion (RPE). Results: Tre, HR and RPE decreased, while PV (3.3 ± 5.6% young, 2.8 ± 3.3% middle-aged) increased within both groups (p <0.050). SL did not change within either group. Groups differed in HR, but demonstrated similar Tre, PV, RPE and SL. Pre- and post-acclimation VO2max did not differ within or between groups. Conclusions: Young and middle-aged, aerobically fit males responded similarly to high intensity exercise-heat acclimation. Both groups appeared to fully acclimate, although they may have experienced a latent HR response. The similar responses suggest that aging-related biological changes do not impair aerobically fit males' thermoregulation through their mid-40s during high intensity, hot weather exercise.
Anthropometric results obtained during pre and post testing of metabolic, hemodynamic and anthropometric variables (mean±SD) Control Group Experimental Group
The present study analysed the effects of 16 weeks of an exercise programme on blood lipids, blood pressure, anthropometry and functional autonomy of elderly women. Fifty-four elderly women were divided into two groups: experimental group (EG) (68.9 ± 6.8 years), who underwent a 16-week training programme, and a control group (CG) (66.6 ± 6.0 years). All metabolic parameters changed over the 16-week period for the EG: total cholesterol (228.0±34.8 to 190.5±22.5 mg/dl), HDL (48.4±4.9 to 53.4±6.0 mg/dl), LDL (162.4±16.6 to 115.2±11.9 mg/dl), VLDL, (31.5±4.0 to 29.7±4.4 mg/dl), triglycerides (127.5 ± 53.5 to 105.1 ± 30.2 mg/dl) and glucose (94.8±11.3 to 85.9±5.9 mg/dl). CG showed changes in total cholesterol (220.0±30.5 to 198.3±29.1 mg/dl) only. For blood pressure, EG improved after training with respect to systolic blood pressure (145.3±4.3 to 136.2±10.9 mmHg) and diastolic blood pressure (95.8±8.6 to 85.9±8.6 mmHg), while the CG showed improvement in systolic blood pressure (147.8±12.2 to 140.1±12.8 mmHg) only. Body mass index was lower after training for the EG (29.0±5.2 to 28.4±5.1 kg/m2). For functional autonomy, EG improved performance in the five tests evaluated: 10m walk test (C10m) (10.4±4.5 to 7.9±2.3 m), rising from a seated position (LPS) (12.4 ± 4.3 to 10.5 ± 3.0 s), rising from the prone position (LPDV) (7.9±4.3 to 6.2±3.6 s), rising from a chair and moving around the house (LCLC) (63.8±16.5 to 55.8±12.3 s) and testing to put on a shirt (VTC) (18.9±8.7 to 15.6±6.9 s). The authors conclude that a multiple-component physical activity training programme improves blood lipids, blood pressure, BMI and measures of functional autonomy in older women.
In this case report a dislocation of the hip received during a judo competition is described. This extremely uncommon condition requires special attention because a dislocated femoral head should be reduced within six hours to reduce the risk of avascular necrosis of the femoral head (AVNFH). Safe return to the pre-injury level of sports depends on the rehabilitation process, the athlete’s fear of movement, and development of AVNFH or osteoarthritis (OA) of the hip joint. © 2014, International Federation of Sports Medicine. All rights reserved.
For the achievement of peak sporting performance, many variables need to be optimized, including physical and mental training, rest, nutrition, team dynamics and tactics. Environmental factors on and around the competition venue may also have a significant impact on performance. This review highlights several important environmental conditions and their possible effect on exercise performance. The factors discussed include temperature, ultraviolet radiation, allergens, atmospheric pollution and altitude. The climatic, atmospheric and weather conditions likely to be prevalent in Beijing at the 2008 Olympic Games are presented and recommendations are provided for optimising performance under these conditions during August, the time at which the Games will be held.
A balanced intake of macro- and micro nutrients is crucially important for conditioning, recovery from fatigue after exercise, as well as for injury prevention. An increasing number of athletes have adopted vegetarian diets for one or more reasons and actually there is no available evidence to support either a beneficial or a detrimental effect of a vegetarian diet on sport performance. Therefore, it is widely accepted that appropriately planned vegetarian diets can provide sufficient nutrient energy with an appropriate range of carbohydrate, fat, and protein intake to support performance and health. On the other hand, questions have been raised by some investigators regarding unique risks of the vegetarian diet, including oligomenorrhea and amenorrhea, iron deficiency, vitamin B(12) deficiency, vitamin D deficiency, and impaired mineral status. In the present overview those items are described with the aim of identifying intervention warnings for vegetarian athletes.
In many sport disciplines the delivery of oxygen to muscles plays a critical role. Indeed, muscle performance declines during prolonged and intense activity as a consequence of the shift from the aerobic to the anaerobic metabolism with an increase of lactate. To enhance the aerobic capacity two alternatives may be used: increasing either the transport or the delivery of oxygen. In this setting, erythropoietin use is the practice of illicitly using a drug to improve athletic performances. In the present overview, old and newer erythropoietic stimulating molecules are described with a special emphasis on their potential side effects. Direct and indirect detection methods are briefly described with the aim of mentioning their roles and limits with regard to anti-doping strategies.
Background: Recently, there has been increasing interest in gathering epidemiological data through standardised assessment for the health of athletes. Research Question: This study prospectively examined the epidemiologic profile of acute and chronic sports injuries incurred by the national athletes of the Korean Olympic Committee (KOC) during the 16th Summer Asian Games. Type of study: Prospective epidemiologic surveillance Methods: All medical personnel of the KOC were instructed to complete and return a daily injury report form, and all physicians were asked to fill in the clinical diagnoses after a thorough examination. The frequency, characteristics, and clinical diagnoses of all sports injuries were examined, and the incidence and injury risk across different sports were compared. Chronic conditions prevalent in elite athletes were also assessed. Results: The number of sports injuries that were reported was 725 (430 athletes); of these 725, 288 were acute injuries (209 athletes), including 68 recurrent injuries (58 athletes), and 437 were chronic injuries (305 athletes). The largest number of acute and recurrent injuries was reported in athletics (37 acute injuries and 16 recurrent injuries). Acute injuries were incurred in competition (n=126; 43.8%) and during practice (n=162; 56.3%), and recurrent injuries in competition (n=18; 26.5%) and during practice (n=50; 73.5%). The incidence rate (IR) of acute injuries was 37.9 (95% Confidence Interval {left tortoise shell bracket}CI{right tortoise shell bracket}; 33.5-42.3) injuries/1,000 athlete-exposures (AEs), and the IR of recurrent injuries was 9.0 (95% CI; 6.8-11.1) injuries/1,000 AEs. Athletics also showed the highest IRs for both acute and recurrent injuries (245.0 injuries/1,000 AEs, 95% CI; 166.1-324.0, and 106.0 injuries/1,000 AEs, 95% CI; 54.0-157.9, respectively). 26.4% (95% CI; 23%-30%) of the registered athletes sustained acute injuries, and 7.3% (95% CI; 6%-9%) of them incurred recurrent injuries. Basketball (67%, 95% CI; 48%-86%) and field hockey (66%, 95% CI; 49%-82%) showed high IPs for acute injuries and the IP for recurrent injuries was high in athletics (27%, 95% CI; 14%-40%). Lateral ankle ligament sprain was the most frequent acute injury (n=28; 9.7%, 95% CI; 27-29), whereas calf muscle cramps was the most frequent recurrent injury (n=11; 16.2%, 95% CI; 10.3-11.7). The prevalence of chronic injuries was highest in wrestling (n=31; 7.1%, 95% CI; 26.7-35.3), and the most prevalent chronic injury was chronic ankle instability and lumbar myofascial pain (n=51; 11.7%, 95% CI; 49.6-52.4, respectively). Conclusions: The statistics of this epidemiologic study indicated the wide range of the incidence, prevalence and characteristics of injuries in different sports during the 16th Summer Asian Games, and the data from the sports might be compared using the statistical measures of the injurysurveillance in this study. Therefore injury prevention programmes should be tailored to the injury profile of the respective sport for the major international multi-sport events.
Diagnosis of ligament and musculotendinous unit injury and overuse represents an increasingly important clinical problem in the athletic population. A review of recent literature on diagnostic ultrasound in sports medicine is presented. There is limited, but increasing, objective proof to support the use of diagnostic ultrasound using in common sports disorders. The improvements in ultrasound allow visualisation of soft tissue injuries in exquisite detail. The ability to perform interventional procedures real-time with ultrasound is an additional benefit compared to MRI. An overview is given of ultrasound applications in sports medicine.
Non-surgical treatment is recommended as the initial strategy in tendinopathies at all locations. In general, the treatment approach is multifactorial and consists of both exercise and physical therapy. Different methods aim to stimulate collagen synthesis, reduce tissue adhesions and free nerve endings, as well as optimising the stress onto the tendon by improved load management. As a result of recent evidence, it can be stated that eccentric training regimens lead to favourable results with less pain and improvement in function within 12 weeks of application. Shock wave and laser therapy show promising results on pain reduction at some locations. Systemic or local usage of medication has to be considered as an additional, practically relevant therapeutic tool without significant evidence for use in athletes. Location-wise modification of treatment strategy has to be undertaken.
Bone is a remarkable, very strong and flexible structure. Running and jumping, together with muscle work, and lever arms generate ground reaction forces helping to model developing bone. Peak bone mass, strongly determined by genetic factors and exercise, is one of the most important factors in bone health. The amount of bone accrued, especially before the end of the third decade of life, is a major determinant of the risk of fractures in later life. Bones are a living tissue and constantly changing throughout one's lifetime, thus manifold osteopathies are known. The bone itself does not need to be the primary cause of diseases, but rather be affected in combination with other diseases. Besides osteopathies, such as fractures, achondroplasy, Morbus Paget, etc., osteoporosis which is defined as a systematic skeletal disease characterised by low bone mass and micro-architectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture, according to the World Health Organization (WHO), is ranked among the ten prime widespread diseases. Bone mineral density (BMD) is used in diagnosing osteoporosis. Anamnesis and clinical findings, bone densitometry, medical imaging and the basic laboratory are basic diagnostics for osteoporosis. Physical inactivity, medication, sex, age, low body mass index, need to be regarded as risk factors for osteoporosis. Acute and chronic pain caused by osteoporosis restricts activities of daily living and diminishes quality of life. FRAX (a diagnostic tool), disregarding all advantages and disadvantages of the computer based algorithm, calculates the country-specific 10-year-probability of a major hip fracture. Several different bone disorders, especially osteoporosis, are among other reasons linked to a sedentary lifestyle and poor nutrition habits. Preventing osteoporosis is a lifelong task, involving aspects such as nutrition and body weight, physical activity, as well as the abuse of dependence-causing substances. Thus lifestyle modification, calcium, vitamin D3, physical activity, exercise and prevention of falls establish the basic therapy for osteoporosis. Building on this, secondary and tertiary prevention addresses the risk of fracture and repeated fracture prevention via medication. Physical medicine represents not merely an alternative, but rather a complementary and inevitable therapy option in treating bone disorders, especially osteoporosis. Consequently, physical exercise plays a key role in reducing fractures and repeated fractures. The study situation concerning physical activity and osteoporosis is so far not easy to evaluate, because interventions disagree on duration, intensity, specificity, and subject groups. Although there is a vast amount of literature on physical activity (described as one of the best medications against diseases of lifestyle), there is a lack of consensus according to the best dose-response correlation for bone health. In the context of bone health, particular attention is paid to whole body vibration. Whole body vibration may improve muscle strength and power and consequently bones and balance as well. However, the mechanism is not well understood and the exact role is still debated and cannot be uniformly prescribed. As society grows older and lifestyle becomes more and more sedentary, the occurrence of osteoporosis should be held as low as possible and therefore the diagnostic methods need to take action to recognise indications of osteoporosis as soon as possible and be able to determine the most effective treatment options.
Background: Exercise-induced changes in muscle force depend on metabolic fatigue, muscle damage, and low-frequency fatigue. As far as is known, no study has investigated how these types of fatigue manifest during a repeated bout of exercise shortly after the first bout. Research objective: To examine changes in muscle performance after two bouts of maximal jumping or cycling exercise with a short interval between bouts. Type of study: Experimental laboratory study. Methods: Men (n=10) performed two bouts of jumping (50 continuous jumps) or cycling (30s Wingate test) with a 60min rest between bouts and a one-month interval between jumping and cycling. The peak quadriceps muscle force evoked by electrical stimulation at 15Hz (P15) or 50Hz (P50) was measured before exercise and 2-, 30-, and 60min after exercise. Muscle soreness and creatine kinase activity were determined 48h after bout 2. Results: P15 and P50 decreased after the first bouts of jumping and cycling and did not recover to the pre-exercise level within 60min (P<0.05). Consequently, the second bout was performed with a still-depressed stimulation force. However, P15, P50, and the P15/P50 ratio did not decline more strongly after bout 2 than after bout 1. Conclusions: Two different types of exercise caused similar reductions in electrically evoked muscle performance within 60min of exercising. A second bout of jumping or cycling shortly (60min) after the first bout and before full muscle recovery did not exacerbate the impairment of muscle function.
Background: In taekwondo (TKD), the incidence of concussion is four times greater than in American gridiron football. Biomechanical studies of concussion in taekwondo are scarce. Research question: To assess the effect of head impact biomechanics as a result of taekwondo kicks. Type of study: Between-groups design. Methods: Two male (22.0±0.0 years, 184±0.0cm, 81.3±1.8 kg) and two female (0.0±2.8 years, 171.0±1.4 cm, 63.0±5.2 kg) elite taekwondo athletes participated in this study. Head linear acceleration (RLA) and head injury criterion (HIC) data were collected from five different head kicks randomly performed five times. A Hybrid II Crash Dummy head (H2D) was instrumented with a tri-axial accelerometer. Results: Significant differences were found between kicks in RLA (eta2=3.8) and HIC (eta2=4.6) in the men and women (RLA, eta2=4.5 and HIC, eta2=4.7). Post-hoc analyses showed differences in RLA between the jump back kick (61.6±31.0 g) and clench axe kick (33.3±11.1 11.1 11.1 g) in males (ES=0.9). HIC analysis revealed differences between the jump back kick (556.8±679.2) and jump hook kick (191.0±37.2) (ES=0.7) and in head velocity between the turning kick (5.0±0.5 5.0±0.55.0±0.5 and jump hook kick (3.2±1.3 m.s 3.2±1.3 m.s3.2±1.3 m.s 3.2±1.3 m.s 3.2±1.3 m.s -1, ES=1.1) in the males. In the females, there was a difference between the jump back (HIC: 236.8±104.3 236.8±104.3 236.8±104.3236.8±104.3236.8±104.3 236.8±104.3) and clench axe kicks (22.2±11.2) (ES=1.2) and in foot velocity between the turning (15.7±1.2 15.7±1.2 15.7±1.2 -1) and clench axe kicks (9.1±2.3 9.1±2.39.1±2.3 -1) (ES=1.2). Conclusions: Previous research reported RLA values of 67.0 g (HIC=167) in boxing compared to 72.8 g (HIC=667) in TKD. These high magnitudes of injury-related measures highlight the need for the implementation of more safety precautions.
Background: In the present study localisation and pattern of spinal fractures due to horse riding-related accidents were analysed. Research question: What is the most common mechanism of accidents of equine-related spinal fractures? Type of study: A retrospective review of patients who underwent spinal surgery due to horse riding-related accidents over a time-span of 10 years. Methods: In consideration of ethics commissions, as well as data protection officers' requirements, data of equine-related spinal injuries were collected from the medical information and imaging systems. Results: Forty-seven spine fractures were found in 45 patients. 40 patients (88.9%) were female and 5 (11.1%) were male. The median age at the time of injury was 38 years (range 15 - 74 years). Over 80% of the fractures (n=38) were localised between level Th11-L2. Type AO A fractures were found in 40 (85.1%), type B in 4 (8.5%), and type C in one (2.1%) of the cases. In one case (2.1%) a fracture on level C1 was classified as Jefferson III and in another case (2.1%) a fracture on level C2 (odontoid fracture) was classified as Anderson II. Conclusions: Falling from the horse on the rump is a common mechanism of accident during riding activities. Then, axial forces exerted through the rump and transmitted through the lumbar spine are leading to fractures between Th11 and L2. Therefore the development of new safety vests which protect the thoracolumbar junction is important if the number and severity of spine injuries during riding activities in the future are to be reduced.
The diagnosis of acetabular labral tears in the athlete with disabling hip pain can be challenging to the sports medicine practitioner. Recent advancement in our clinical skills, imaging techniques and the development of hip arthroscopy has played a significant role in managing these sports-related hip injuries back to their sport. This article will highlight evaluating and managing athletes with hip labral tears and femoroacetabular impingement syndrome and the use of advanced arthroscopic techniques to treat these disorders.
Risk factors for Achilles tendon injury
Objective: This review examines the relationship between symptoms/signs of Achilles tendon injury and changes in morphology and blood flow in the tendon and also the effects of an acute exercise bout on morphology and blood flow in the Achilles tendon. Data sources: PubMed and ISI Web of Science were searched from 1983 to 2007 using the terms Achilles tendon, blood flow and vascular, disease, imaging and ultrasound, and exercise. Additionally, the references of papers identified through this search were examined for relevant studies. Study section: One hundred and fourteen studies were identified that examined Achilles tendon disorders, risk factors for disease, and imaging of the Achilles tendon. A further twenty-four studies were identified that looked at the vascularity of the Achilles tendon, the association of the vascularity with symptoms and pathology, and the effect of exercise on tendon vascularity. Data extraction: Studies were critically evaluated and summarised in this review. No meta-analytic procedures were performed. Data synthesis: There is not always a clear relationship between morphological changes and the presence of symptoms and signs. The majority of studies show that there is a relationship between neovacularisation and chronic painful tendinosis. However, more recent studies show no association between tendon symptoms and the presence on neovascularisation. Studies show an increase in the blood flow in the Achilles tendon in response to exercise. Conclusions: Some, but not all, studies show an association between neovascularisation and chronic painful tendons. Studies show that blood flow in a tendon increases in response to an acute bout of exercise, and that this returns back to normal post-exercise and that this response may not always be pathological. Future studies should examine the long-term consequences of this repeated transient increase in tendon blood flow in response to an acute exercise bout. The precise mechanism for these changes in blood flow will also require further investigation.
Regular participation in physical activities is associated with the risk of developing musculoskeletal injuries, including soft tissue injuries to tendons. Although there is a high incidence of soft tissue injuries, the aetiology of these tendon and other musculoskeletal injuries are not fully understood. Both intrinsic and extrinsic factors have been shown to be associated with tendon injuries. More recently, studies have suggested that there is also, at least in part, a genetic component to sports injuries such as Achilles tendon, rotator cuff and anterior cruciate ligament injuries. Recent research has shown that specific variants of the COL5A1 and TNC genes are associated with Achilles tendon injuries in physically active individuals. Both genes encode for important structural components of tendons. The COL5A1 gene encodes for a component of type V collagen which forms heterotypic fibres with type I collagen. The protein is believed to play an important role in regulating fibre diameter and strength. The TNC gene, on the other hand, encodes for the extracellular matrix protein tenascin C, which is believed to regulate the tissues response to mechanical load. To date, only variants in two genes have been shown to be associated with Achilles tendon injuries. In future, specific genotypes that are associated with increased risk of tendon and other musculoskeletal injuries may result in prevention and treatment of injuries by identifying higher risk individuals.
Effect of strength training intensity on the post exercise blood pressure response 
Effect of strength training in circuit format on the post exercise blood pressure response 
Objective: Magnitude and duration of the hypotensive response after a strength training (ST) session may in part depend on the manipulation of ST variables. This review examines the effect of the ST variables on the hypotensive response after a ST session. Data sources: Thirty-two studies were included in this review. Studies concerning the post-exercise hypotensive response of ST session were searched on MEDLINE, Science Citation Index, National Library of Medicine, Scopus, Sports Discus, Scielo, and CINAHL utilising the following keywords and respective abbreviations: circulation, hypotensive effect, hypotensive response, hypotension, hypertension, high blood pressure, combined with resistance training, resistive exercises, resistance exercises, resistive exercise, strength training, weight training and weight lifting. Names of authors cited in some studies were also utilised in the search. Hand searches of relevant journals and reference lists obtained from articles were also conducted at the Federal University of Rio de Janeiro libraries, Brazil. The last search was performed in July 2012. Conclusions: The majority of acute studies support that ST produces a post-exercise hypotensive response after a single session. Larger hypotensive responses to ST are observed using higher loads (6RM, 80% 1RM) with trained subjects, moderate loads (40% 1RM) with untrained subjects, higher volumes (number of exercises), multiple sets (3 sets or more), large muscle groups (total body), circuit training programs, longer rest intervals with a traditional training format and shorter rest intervals with a circuit training format, and alternated exercise orders (upper body x lower body). The effect of age on the hypotensive response indicates that older compared to younger subjects show a greater hypotensive response after ST. In addition, some studies indicate that young trained subjects have a greater and longer hypotensive response after ST compared to young untrained subjects, while this latter population may show a momentary blood pressure elevation after ST, especially with higher training intensities (80% 1RM). © 2014, International Federation of Sports Medicine. All rights reserved.
Diseases of the liver may have a significant impact on exercise capacity and physicians' recommendations for the athlete. Acute viral hepatitis is a systemic infection affecting the liver predominantly. Knowledge about the impaired hepatic function as well as hazards for other athletes especially in contact sports is mandatory for professional support. Differential diagnosis includes metabolic diseases, hereditary and autoimmune diseases as well as toxic and drug-induced alterations. The clinical spectrum of chronic hepatitis ranges from asymptomatic illness at one end to fatal hepatic failure. A close workup is recommended and the expertise of a liver centre often is essential. New drug developments allow the therapy of viral hepatitis with only minor or even without deterioration of athlete's performance. According to the severity of liver damage recommendations regarding physical exercise should be made.
Compartment syndrome is a condition where high pressure within a muscle compartment reduces capillary blood perfusion below the level necessary for tissue viability. A variety of injuries and medical conditions may initiate acute compartment syndrome, including fractures, contusions, burns, bleeding disorders, post-ischemic swelling, and gunshot wounds. Exertional compartment syndrome is a well-recognised clinical entity, which can have an acute or chronic presentation, and is associated most often with unaccustomed exercise. This case report discusses a 15-year-old girl who for two years felt transitory pain in the right peroneal compartment when she played sport. After many days of horseback riding, she sustained a sudden increase of the antero-lateral leg pain. The pressure of her lateral leg compartment rose to 100mmHg. Emergent fasciotomy of the lateral compartment of the right leg was performed, and showed partially necrotic peroneal muscles. The reported case is unusual because the pathology was localised to the peroneal compartment only and left the 3 other loges unaffected. Only two other reported cases of exertional compartment syndrome from prolonged horseback riding has been found in the medical literature. The particular mechanism of the peroneal compartment as a result of horseback riding in children is also discussed.
During extended heat exposure, humans can experience three phases of heat adaptation. These start with the cardiovascular, sudomotor and neuroendocrine reactions induced by an acute heat exposure, progressing to an amplification of these responses (Phase two: positive adaptation), and possibly ending with the more efficient negative adaptation (Phase three) seen in indigenes from hot climates, where skin blood flow and sweating are reduced. This review briefly describes these physiological changes and provides a theoretical background underpinning adaptation strategies. Gender differences in the acute and adaptation responses are not discussed. Using simple modelling, there is a development of the key principles that are essential to evaluating the need for heat adaptation in various sports, and there is discussion of the disadvantages of heat adaptation. Several adaptation practices are described and evaluated relative to the needs of the athlete. From these, it is concluded that living and training under hot conditions may best improve performance in the heat. However, since high-intensity training is invariably hard to sustain in the heat, it is recommended that athletes live in the heat, experience heat under the pressure of competition, acclimate for a specific climate and then undertake high-quality training in the cool. Athletes must not ignore the psychological aspects of preparing for competition in the heat, since inappropriate choices can undo years of physiological preparation.
Chronic endurance training increases an athlete's aerobic capacity and results in improved cardiocirculatory work economy, maximum performance, and enhanced oxygen uptake. The extent of the adaptation depends on individual factors such as frequency, intensity, and duration of training, muscle fibre type, and genetics. The functional range of heart rate, cardiac contractility, diastolic function, and blood pressure increases, while cardiocirculatory work is more economical, and maximum oxygen uptake (VO2max) is improved. Symmetric enlargement of the heart begins when endurance training exceeds individual functional limits, resulting in both left and right ventricular and atrial hypertrophy in response to the increased workload placed on the heart. Routinely examined by echocardiography, the myocardial hypertrophy is related to the increase in the interior end-diastolic volume. In contrast to pathological forms of cardiac wall hypertrophy, the mass/volume ratio, and therefore the maximum systolic wall stress remains constant. In addition, functional and structural changes occur in the vascular system. Cardiac adaptations to exercise, including function and size of the heart, regress in healthy people who become inactive and have no structural heart disease.
As adolescent athletes place increasing demands on their bodies, injuries in this population are frequent and becoming more common. Overuse injuries, rather than acute traumatic events, comprise the majority of injuries in adolescents. These injuries, as in adults, are a result of poor form, poor habits, and poor training patterns. In addition, anatomic variations in the hind-foot, mid-foot, and forefoot may predispose an athlete to specific injuries. Prevention of these injuries and early intervention by an orthopaedist can decrease the athlete's time lost to injuries and potential long-term adverse effects. The objective in this paper is to review common sports-related injuries of the foot and ankle in the adolescent athlete, with particular attention paid to overuse injuries in terms of contributing factors, prevention and treatment.
Background: Taekwondo (TKD) is a popular combat sport renowned for its kicking techniques. With repeated practice, it may enhance the sensorimotor performance and balance of its practitioners. Research question: This study aimed (1) to compare the effects of short-term and long-term TKD training on the lower limb joint proprioception, muscle strength and balance performance of adolescents, and (2) to explore the relationships among these three outcome measures. Type of study: Observational study. Methods: Thirty-one adolescents including long-term (n=11), short-term (n=10), and non-practitioners (n=10) of TKD participated in the study. The knee joint position sense, isokinetic strength of the quadriceps and hamstrings, and sway in prolonged single-leg standing were measured. Results: Long-term TKD practitioners made significantly smaller errors in the knee joint repositioning test than the control group (p<0.01). No significant difference was found in the body-weight-adjusted isokinetic peak torque of the quadriceps (p>0.01) or hamstrings (p>0.01) among the three groups. Both short and long-term TKD practitioners swayed significantly slower than control participants while standing on one leg (p<0.01). The accuracy of knee joint angle repositioning was significantly correlated with sway velocity (r = 0.499, p<0.01). Conclusions: More than one year of TKD training can improve single-leg standing balance. The better postural stability demonstrated by long-term TKD practitioners may be associated with better knee joint position sense rather than knee muscle strength. Physiotherapists may therefore suggest long-term TKD exercise for adolescents to improve balance.
Percentage of injuries according to injury location and severity (based on missed training)
Time of interviews during the two-year data collection
Distribution of injury type according to severity
Background: Injury registrations of competitive young athletes are crucial for injury prevention. Particularly in alpine skiing, limited published data exist. Research question: Aimed to profile the rate of injuries affecting skiers admitted to a ski boarding school. Of particular interest was the comparison of overuse and traumatic injuries during the winter and summer seasons. Type of study: 2-year retrospective survey. Methods: Multiple interviews were conducted with 104 elite alpine skiers, ages 15-18 years, from a ski boarding school in Austria. The injury risk and characteristics of ski specific injuries were evaluated. Results: Overall, 89 skiers reported a total of 235 injuries (88 among females, 147 among males). Of the 61 male skiers, 40 sustained at least one traumatic injury (injury risk = 0.67) and 34 reported an overuse injury (injury risk = 0.56). Of the 43 females, 29 suffered at least one traumatic injury (injury risk = 0.67), and 26 reported an overuse injury (injury risk= 0.60). The risk of sustaining a traumatic injury was higher during the winter season (RR 1.39, 95% CI 1.02-3.42, P<0.05), and these injuries mainly affected the lower extremities. During the summer season, there was a higher risk for overuse injuries (RR 1.46, 95% CI 0.96-2.20, P<0.05), and most of these injuries were localised to the trunk and back. Conclusion: The occurrence of traumatic injuries during the competitive season is high. Overuse injuries accounted for a relatively high proportion of time-loss injuries during summer training, suggesting that we should focus not only on traumatic injuries but also on overuse problems.
Demographic information of the sport participants 
Background: It is well known that successful sport participants differ from less successful sport participants regarding their sport psychological skills. Despite the differences regarding the sport psychological skills, gender is also an important interpersonal factor in competitive sport that needs to be taken into account when dealing with male and female sport participants Objective: The aim of the study is to determine the difference in sport psychological skills between male and female adolescents sport participants. Method: A quantitative cross-sectional research design with a convenient sample was used in which the data was obtained by means of the ACSI-28 questionnaire. One hundred and sixty-two Grade 8 learners (77 boys and 85 girls) participated in the study. Gender differences were analysed using an independent t-test, while effect sizes (d) were calculated to determine practical significance. Results: Male and female groups did not differ significantly or practically in any of the 7 subscales for sport psychological skills. Conclusions: From the results of this study one can assume that 13-year-old males and females exhibit the same sport psychological skills and can therefore be treated as a homogeneous group and be subjected to the same mental skills training programme. © 2014, International Federation of Sports Medicine. All rights reserved.
Background: The continuous growth of the elderly population is forcing developed nations to invest effort in the search for interventions and physical exercise programmes, with the aim of increasing the well-being and quality of life of this adult population. Research question: The purpose of this study was to determine the efficacy of physical exercise in the elderly using different intervention methodologies (recommendation, home prescription, and monitoring). Type of study: Experimental study. Methods: One hundred subjects who were 55-70 years of age were recruited and randomized into four groups of 25: CON=control, REC=recommendation, PRE=prescription, and MON=monitoring. The participants followed a structured physical exercise programme for 12 weeks. Each participant’s physical condition was evaluated before and after the intervention using a battery of tests that included the scoring of strength, flexibility, balance, and aerobic resistance. Results: The MON group showed significant improvements in all variables (p<0.001). However, the PRE group did not exhibit increased performance in resistance or balance. The MON and PRE groups were significantly different in all variables studied (p<0.01) except for equilibrium with eyes open. Nonetheless, significant improvements in the strength variables were observed in the PRE group compared to the CON and REC groups (p<0.01 and p<0.05). The improvements in resistance, flexibility, and balance were not significant. Conclusions: A WREP programme is useful for improving physical conditions in both a prescribed home form and a monitored form. However, a simple recommendation does not seem to be sufficient. Nevertheless, the exercise with instructor has greater impact on the physical health of the elderly. © 2014, International Federation of Sports Medicine. All rights reserved.
Background: This study compared walking frequency and associated variables between older males and females living in Spain. Type of study: Cross-sectional analysis. Methods: Logistic regression was used to determine differences in various intensities and durations of walking. The sample consisted of 1,504 people over 60 years of both genders. Results: For low frequency of walking, there were no significant differences between males (68.2%) and females (68.4%). When the frequency increased to five days per week, the differences were significant: males (51.5%), females (43.5%). Level of education was found to be associated with the likelihood of walking: males (OR=1.9), females (OR=1.4) and perceived physical condition males (OR=3.0), females (OR=4.6). Conclusion: Overall, the probability of walking, at a faster pace with the purpose of maintaining or improving fitness, was the same for males and females. However, the males walked more frequently than the females. Moreover, females with low self-rated physical fitness levels were most unlikely to walk on a daily basis. Physical inactivity was associated with low levels of education, particularly among males. These data suggest that the older adult Spanish population is insufficiently active and that females and those with low levels of education were the least likely to walk on a daily basis.
Introduction: Reduced VO2peak, muscle mass, increased fat mass and immunosenescence have been associated with aging. This study examined the effects of exercise on selected cytokines in younger and older individuals, and after 12 weeks of aerobic exercise training in older individuals. Methods: Serum levels of interleukin-6 (IL-6), interleukin-1 beta (IL-1 β) and interleukin-10 (IL-10) were measured before and after maximal and sustained submaximal (70% VO2peak) tests in sedentary young (22 ± 3 years, BMI = 24.9 ± 3.7 kg/m2) and older subjects (75 ± 7 years, BMI = 25.1 ± 3.5 kg/m2) prior to and after training. Results: There were no significant differences in baseline levels of IL-1β, IL-6 or IL-10 between younger and older subjects. In younger subjects, IL-6 (33%) and IL-1 β (25%) were increased after the maximal exercise test, whereas IL-6 was increased (112%) after the submaximal test (P< 0.05). In older subjects pre-training, levels of IL-6, IL-1 β and IL-10 were not affected by acute exercise. In older subjects after training, IL-6 increased in response to acute maximal and submaximal exercise, 17% and 44%, respectively. Conclusion: Older subjects did not demonstrate a significant inflammatory response (IL-1 β) to acute exercise; however their anti-inflammatory (IL-6) response was blunted, and was only partially restored by 12 weeks of exercise training. Further studies are needed to examine the effects of longer-term chronic exercise on immune parameters.
Background: Wii Fit™ is an exergame that purports to improve balance through a variety of balance training exercises. Despite relatively little research documenting the effects of Wii Fit™ on balance this technology has been implemented in educational and clinical settings, often with the direct goal of balance enhancement. Research question: The current study examined the effects of three weeks of Wii Fit™ balance activities on balance in a group of healthy, young adults. Type of study: quasi-experimental design with pre/post testing of effects of intervention. Methods: A total of 19 individuals underwent an initial balance assessment using the star excursion balance test (SEBT) followed by a total of 8 balance training sessions using Wii Fit™ balance activities. At the end of the three-week training period the SEBT was re-administered both immediately following the final Wii training session and again 24 hours later on a subset of 11 participants. Results: Significant post-training improvements were observed for all SEBT reach directions expect posterolateral and anteromedial. This was interpreted as indicating that dynamic balance had improved in this group of young adults. Conclusions: Following Wii Fit™ balance training participants SEBT performance improved in 6 of the 8 directions. These results suggest that Wii Fit™ balance activities can positively impact dynamic balance as measured by the SEBT. Although replication of this study with other populations is needed, these initial findings suggest that Wii Fit™ may provide an alternative to more traditional balance training activities.
Objective: To assess the acute effects of concurrent training (CT) on plasma leptin levels in overweight adults. Material and methods: Quasi-experimental research methods were used. A sample of twenty individuals (27.7 ± 5.1 years-old, BMI 27.08±1.42) was randomly divided between the experimental group (EG: n=10) and the control group (CG: n=10). After subjects had fasted for 12 hours, blood samples were collected from both groups, and plasma leptin levels were assessed. Forty minutes after breakfast, the EG performed CT which included an indoor cycling class (40min, OMNI 5-7) followed by resistance training (3 series performed until exhaustion in the supported row machine, leg press, straight bench press, knee extensor, elbow flexor, knee flexor and elbow extensor, 85% 1RM, 2-3min interval). The CG did not perform the physical exercises. At the end of the CT, blood samples were collected from the EG. Descriptive statistics were used and for the inferential analysis a two-way ANOVA was undertaken. The Shapiro-Wilk test was used to check homogeneity and Tukey's Post-Hoc test was used for normality analysis. The significance level adopted was p<0.05. Results: The EG (Δ% = 2.92; p = 0.01; 15.05±3.32ng/mL for 12.13±3.01ng/mL) and CG (Δ% = 5.32; p = 0.00; 26.04±9.13ng/mL for 20.72±8.51ng/mL) had significant reductions in plasma leptin levels. Conclusion: In its acute phase, CT causes a reduction in the plasma leptin levels of overweight individuals.
Background: Head trauma may result in many kinds of otoneurologic disorders. However, there are very few studies associated with the evaluation of the disorder. Research question: The aim of the study is to clarify the effects of long-term impact to the head in advanced boxers regarding vestibular evoked myogenic potentials (VEMP). Type of study: Prospective study. Material and methods: VEMPs were collected from 14 advanced boxers (13 M, 1 F, aged 16-28 years). The otoscopic findings, audiograms and caloric test were recorded. The VEMP responses of strong side (right for right-handed) and weak side were compared to each other and to the healthy volunteers. Results: The 14 enrolled subjects had been engaged in the sport of boxing for 4 to 15 years (median: 8.9 years). In comparison with the control group, the results of the caloric test of the subjects were not significantly different (p>0.05). The VEMP responses in boxers showed significant delay of p13 and n23 latencies in both strong side and weak sides in comparison with healthy volunteers (p<0.05). Moreover, the p13 and n23 latencies of VEMP responses showed significant delay over strong side as compared with the weak side (p<0.05). Conclusion: VEMP responses were significantly affected by chronic head trauma in the boxers. Furthermore, p13 and n23 latencies of VEMP responses of strong side showed significant delay compared with those of the weak side.
Objective: Scientific studies of specific training interventions to evoke adaptive biomechanical, aerobic and oxygen-independent cellular responses for improving cycling performance in already well-trained cyclists are limited. Consequently, related research of metabolic markers and underlying mechanisms found to be potential determinants of best competitive cycling performance are reviewed. Applicable specific training strategies which may have an impact on performance are discussed. Data sources: For this review, scientific texts, peer-reviewed journals, electronic (Web) publications and published abstracts of papers presented at conferences were identified through Highwire Press and PubMed. Study section and data extraction: The selected papers examined were from peer review established sports science and physiology journals specifically related to exercise physiology. Conclusions: Achieving the best competitive cycling performance requires the understanding and implementation of sound research in support of successful training paradigms. Knowledge of the physiological mechanisms following a training regime will allow valid training practices to be implemented. The inclusion of a combination of strategies focusing on pedalling dynamics, post-exercise recovery, hypoxia training, and sprint interval training may prove responsible for observed increases in exercise performance at sea level and at altitude.
Cardiovascular behaviour at rest, before and after caffeine or placebo ingestion Pre-ingestion Post-ingestion
Cardiovascular behaviour before and after an aerobic exercise Pre-exercise Post-exercise
Components of heart rate variability at baseline and average of 60min post-ingestion and post-exercise PLACEBO CAFFEINE
Background: The consumption of a dose of caffeine (CAF) may attenuate post-exercise hypotension. Research question: The purpose was to verify the effect of a dose of CAF on systolic (SBP) and diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR) and heart rate variability (HRV) after a session of aerobic exercise in normotensive individuals. Type of study: Randomized controlled study. Methods: Ten healthy, physically active men (24.4 ± 4.5yrs; 74.3 ± 11.8kg; 172.8 ± 8.6m; 36.8 ± -1.min -1) were randomly submitted to two experimental protocols in distinct days, in a cross-over double-blind design, with the ingestion of -1 of CAF or placebo and performance of an aerobic exercise in a cycle ergometer at 60% VO 2peak. SBP, DBP, MAP, HR and HRV components were assessed at the pre-exercise rest period, 60 min after substance ingestion and during 60min post-exercise. Results: At the post-ingestion period, there were reductions on basal HR on both sessions and mean rises of 5mmHg on SBP, of 7-8mmHg on DBP and of 6-7mmHg on MAP on the caffeine session. After exercise, there were reductions of 5-7mmHg on SBP, significant on the 30 th and 40 thmin, on the placebo session. During the caffeine session, maintenance of raised HR levels, no difference in relation to the pre-exercise period for SBP and MAP, and higher blood pressure compared to the placebo session. HRV was altered in each session; however there were no differences between the experimental sessions. Conclusion: The ingestion of a -1 dose of CAF apparently does not significantly interfere on the cardiovascular behaviour after a session of aerobic exercise.
Background: Few studies have investigated the effect of exercise order on post-exercise hypotension and heart rate variability (HRV). Research question: The purpose of this study was to investigate the behaviour of blood pressure (BP), heart rate (HR) and HRV after an aerobic training session (ATS), strength training session (STS), combined aerobic and strength training session (ASTS) and in the opposite order (SATS). Type of study: Acute effect study. Methods: Ten men (age 24.5 ± 1.1 years, weight 77.0 ± 3.7 kg, height 1.76 ± 0.8 cm) with previous experience in aerobic and strength training volunteered for this study. STS was performed using eight exercises (with 60% 1RM) and each ATS was performed on a cycle ergometer (60% VO2 peak, 50 min). BP, HR and HRV were measured at rest and for one hour following exercise. Results: The results demonstrated reductions in systolic BP after ASTS and SATS when compared to the control group (CON) (p <0.05), ATS (p <0.01) and STS (p <0.05). On the other hand, HR was elevated after STS (p <0.01), ASTS (p <0.01) and SATS (p <0.05) when compared to the CON group. The HR increase was accompanied by changes in HRV after sessions of STS (p <0.01), ASTS (p <0.01) and SATS (p <0.01) compared to the CON group. Conclusions: Combined sessions of aerobic and strength training with moderate intensity can elicit a hypotensive response in normotensive men independent of session order. Therefore strength and conditioning professionals can prescribe these exercises using different orders if the objective of the training session is to control blood pressure.
Background: Regular physical activity leads to significant changes in terms of the reduction of health-related risks. Research question:The purpose of this study was to investigate the effects of an eight-week step-aerobic dance exercise programme on weight loss and body composition parameters in middle-aged sedentary obese women. Type of study: This study comprised an eight-week randomised controlled trial. Methods: A total of 49 healthy sedentary obese women participated in this study voluntarily. They were randomly divided into two groups: those undertaking a step-aerobic dance exercise programme (n=29) and a control group (n=20). The subjects too part in a step-aerobic dance exercise programme for one hour per day, three days a week for eight weeks. The subjects' Body Mass Index (BMI), weight, waist circumference, waist-hip ratio, four-site skinfold thickness, fat percentage, basal metabolic rate and lean body mass were assessed before and after the completion of the step-aerobic dance exercise programme. Results: After the eight weeks of the step-aerobic dance exercise programme, significant differences were found in the subjects' weight, BMI, body composition parameters, waist-hip ratio (WHR), waist circumference (WC), fat percentage, lean body mass (LBM) and basal metabolic rate (BMR) in the experimental group (p<0.05). There were no significant differences in the control group after the experiment in terms of the same measures (P>0.05). Conclusion: The step aerobic dance programme proved to be a useful exercise modality for weight loss and in terms of body composition. There was a clear response to the eight-week step aerobic dance programme in terms of central obesity in sedentary obese Turkish women.
Background: Nitric oxide (NO) plays a critical role in the recovery stage, in maintaining a large blood flow in skeletal muscle and in promoting recovery after exercise. Research question: This study observed the NO level, NOS activity and the expression of NOS in rat skeletal muscle under normoxic and hypoxic training conditions. Type of study: Randomised controlled study. Methods: Sixty-four male Sprague-Dawley rats were randomly divided into normoxic control group, two-week training, four-week training, six-week training groups; hypoxic control group, two-week hypoxic training, four-week hypoxic training, six-week hypoxic training groups. The classic Griess method was used to test nitric oxide in the homogenate of skeletal muscle. Moreover, methods such as RT-PCR, western blot, etc. were utilised to test the change of the all types of nitric oxide synthase expression. Results: The results showed that the NO content of rat skeletal muscle was significantly increased in two, four, and six-week training subgroups compared with the control group under normoxic conditions; NO content increased in the four-weeks and six-weeks hypoxic training group compared with the hypoxic control group (p <0.05, p <0.01). Under hypoxic conditions, with increasing exercise time, the cNOS activity and the expression cNOS protein was significant different between the training group and the control group, while there was no change in iNOS expression. Conclusions: The data in this study suggested that the hypoxic exercise may promote increases in the NOS and NO levels, counteract the blood vessel contractile effect of hypoxia, and improve the relaxed tone of blood vessels.
A look at the medal podium in almost any international sporting competition reveals that some athletes and certain countries enjoy regular success in particular events. One of the most compelling examples is that of East African runners and their domination of international distance running competition. This phenomenon has led to the suggestion that East Africans possess some inherent genetic advantage predisposing them to superior athletic performances. The concurrent success of athletes of West African ancestry in sprint events appears to have augmented this belief given their similar skin colour. Despite the speculation that African athletes have a genetic advantage, there is no genetic evidence to date to suggest that this is the case, although research is at an early stage. The only available genetic studies of African athletes do not find that these athletes possess a unique genetic makeup; rather they serve to highlight the high degree of genetic diversity in East Africa and also among elite East African athletes. Although genetic contributions to the phenomenal success of East Africans in distance running cannot be excluded, results to date predominantly implicate environmental factors.
Background: The assessment of chronic responses represents a major trend of research in the aquatic environment. Aquatic programmes have gained in popularity due to perceived health benefits. Research question: The aim of this study was to assess chronic adaptations in middle-aged women participants in a head-out aquatic exercise programme. Type of study: experimental, prospective. Methods: Twenty-three middle-aged female subjects participated in a head-out aquatic exercise programme (26 weeks, two sessions per week, 40 minutes per session). Data was collected before starting the programme (pre-test), at the 13th week (post-test 1) and at the 26th week (post-test 2). Body composition was assessed measuring several body skinfolds. Anthropometrical data included measurements of weight, body mass index and several anatomical perimeters. Cardiovascular measures included the resting heart rate, systolic, diastolic and mean blood pressures. Results: Subjects improved their body composition by decreasing their fat mass. While most anatomical perimeters significantly decreased, weight and the body mass index remained unchanged. The systolic and mean blood pressures decreased while the resting heart rate and the diastolic blood pressure remained stable. The main improvements occurred in the first 13 weeks of the programme, since most variables did not show significant variation from that point forward. Conclusions: It can be concluded that: (i) a head-out aquatic exercise programme over 26 weeks promotes a significant improvement in body composition, anthropometrics and cardiovascular response of middle-aged women (ii) major adaptations occur in the first 13 weeks of the programme.
The effects of carbohydrate ingestion on prolonged exercise performance have been extensively studied. Particularly, many studies have paid specific attention to the effect of carbohydrate ingestion on time to fatigue, the effect on the respiratory exchange ratio (RER), the effect that the time at which the carbohydrate is ingested may have on performance, and the optimal amount of carbohydrate to be ingested. In addition, the effect of different types of carbohydrate and the influence of exercise intensity has been studied, including the influence on hepatic glycogenolysis and on ratings of perceived exertion (RPE). The most important findings have been that there is a beneficial effect from ingestion of carbohydrate during prolonged exercise due to prevention of hypoglycaemia, the provision of blood glucose for oxidation late in exercise, and that there is a hepatic glycogen sparing effect as a result ingesting carbohydrate. Importantly, the majority of carbohydrate types are oxidised at similar rates when ingested singularly. However, a mixture of specific carbohydrates ingested together are oxidised at a much higher rate. Despite the volume of research in this area, some questions remain unclear, specifically information pertaining to feedforward control mechanisms in the brain that integrate exercise performance on the basis of feedback from different body organs, and the role that carbohydrate ingestion may have on this control, including the effect of body carbohydrate reserves.
Background: There is emerging evidence that the prevalence of exercise-induced bronchospasm (EIB) is significantly under-reported in many sports. There is little known about the potential performance improvement that may exist when sports players are detected and treated for EIB. Methods: Professional rugby union players with no previous history of asthma volunteered to participate in the study. Each player performed the rugby football union (RFU) fitness test and completed a eucapnic voluntary hyperpnoea (EVH) challenge at baseline and 12 weeks later. A player with a positive EVH result was prescribed beclomethasone inhaler (200 µg; two puffs per day) for 12 weeks. Players with a negative EVH test were randomly allocated to either a placebo inhaler group or acted as controls. Results: Twenty-nine rugby union players (mean ± SD; age 22.1± 4.2 years; body mass 100.1± 6.9 kg; height 1.84± 0.07 m) were recruited. Seven players (24% of total) had a positive EVH challenge with a mean decrease in FEV1 of -13.6 ±3.5% from baseline. There was no significant group difference (P=0.359) in performance improvement of the RFU fitness test between the EVH positive group (mean Δ: -22.3 seconds; 8.0 ± 2.8% improvement), placebo group (mean Δ: -16.5 seconds; 6.7 ± 1.6% improvement), and controls (mean Δ: -12.2 seconds; 5.7 ± 3.5% improvement). Conclusion: Prevalence of EIB in professional rugby union players was 24%. A 12- week prescription of beclomethasone (200 µg) showed similar improvements in RFU fitness test performance in players diagnosed with EIB compared to players with healthy airway responsiveness. © 2014, International Federation of Sports Medicine. All rights reserved.
Background: Currently, a large spectrum of running shoes is available to a runner. Running shoes are manufactured and marketed in various categories ranging from "motion control", "neutral", or "soft shockabsorbing" shoes. Runners, and health professionals advising them, are informed that the use of inappropriate footwear, not based on matching the appropriate shoe category to the lower limb alignment in runners, is linked to an increased risk developing a running injury. Objective: The objective of this retrospective cohort study was to investigate whether runners, who had been advised on running shoes following a clinical lower limb biomechanical assessment prior to purchasing new running shoes, have a reduced risk of developing a running injury when compared to runners who have not been advised in this manner. Methods: The Experimental Group consisted of 177 out of 400 randomly selected runners (44% response rate) from a potential hit of 900 runners who had previously undergone a clinical lower limb biomechanical assessment followed by a running shoe prescription (EXP group = 94). A group of runners matched for age, height, weight and gender, who purchased running shoes through normal means were recruited as controls (CON group = 83). All the subjects completed a previously validated questionnaire that was designed to mainly document training history and running injury incidence (injuries per 100 running sessions) and injury type in the 12-month period following running shoe purchase. Results: An analysis of training and racing history showed that the CON group did significantly more training sessions in the 12 months following shoe purchase. There was no significant difference in the groups with respect to weekly stretch sessions, use of orthotics, and frequency of training on different running surfaces. There was no significant difference in injury incidence between the groups (CON=6.71, EXP=6.04 injuries/100 sessions) or subgroups of runners in each group with either a past history of running injury or no past history. The incidence of specific common running injuries was not different between the groups. Conclusion: A clinical lower limb biomechanical assessment, followed by running shoe purchase, does not reduce the risk of developing a running injury any more than following general advice on running shoe purchase.
With increasing altitudes, athletes will experience marked decreases in endurance performance; occasionally they will develop high-altitude illness, and in rare cases, even life-threatening forms. Thus, the understanding of the physiological basis of performance diminution and the development of high-altitude illnesses is important for the implementation of appropriate preventive and therapeutic measures. Aerobic exercise performance decreases upon ascent to altitude, whereas anaerobic performance remains unchanged. Typically, sub-maximal but not maximal exercise performance improves following 1-3 wk of acclimatization due to an increase in arterial oxygen saturation and haemoglobin concentration from increasing ventilation and decreasing plasma volume, respectively. The falling PiO(2) and the related decrease in PAO(2) and SaO(2) with increasing altitude not only affect exercise performance but are also mainly responsible for the development of high-altitude illnesses. Whereas acute mountain sickness (AMS) represents the most common illness, which is benign and self-limiting in nature, high-altitude cerebral edema (HACE) and high-altitude pulmonary edema ( HAPE) are rare but severe life-threatening illnesses. Beside the most important general preventive measures like pre-acclimatization, slow ascent to altitude, sufficient intake of fluid and carbohydrates, and avoidance of alcohol and nicotine, some drugs such as acetazolamide, COX inhibitors, dexamethasone, nifedipine or salmeterol have proved efficacious in the prevention of altitude illnesses in subjects susceptible to them. The same drugs, oxygen, hyperbaric chamber, and evacuation to low altitude are effective for treatment of high-altitude illnesses.
Anthropometric measurements
Statistically significant time coefficients occurring in the regression model and their symmetrical homologues
Background: Optimal nutrition, especially in terms of protein ingestion, is a tool to enhance the hypertrophic response to resistance training. The ingestion of high amounts of dietary protein in conjunction with resistance training reduces the rate of muscle protein breakdown when muscular hypertrophy of optimal restitution is the goal. Research question: The purpose of this study was to determine if and how protein intake increases muscular mass and volume after a six-month resistance training period in amateurs. Type of study: Longitudinal 'one-within, one-between' study. Methods: The sample group consisted of 13 amateur bodybuilders. The control group consisted of 36 amateur bodybuilders of the same age. Participants followed a controlled specific exercise protocol 3 times/week, using 3 sets of 8-6-4 Maximal Repetitions (MR). Subjects were interviewed about their usual diet to determine their daily protein intake, i.e. 2.03 ± 0.62 and 1.04 ± 0.05g/kg BW, in the experimental and control groups respectively. Anthropometric characteristics (body weight, body girth and skin-folds) were measured. A statistical analysis for longitudinal data was carried out using a random intercept model. Results: No statistical evidence of dietary regimen influence in muscle increase or statistically significant interaction between time and diet were found. The statistically significant changes detected in some muscles (i.e. chest girth p<0.05) come down from time trends, supporting the authors' hypothesis that they had only a training effect on the solicited body segments. Conclusions: This study's data analysis does not justify the excessive protein intake in amateur bodybuilders' diets aimed at increasing muscular mass and volume.
This study was designed to examine the changes of immunological markers in elite (n=7) and club amateur (n=8) triathletes, who completed the 2006 TONG YUNG international triathlon race, by investigating changes of total amounts of leukocytes, neutrophils, lymphocytes, monocytes, immunoglobulins (Igs), IL-6, CK and CRP. Three days prior to the race, all participants had a blood sample drawn from an antecubital vein. Blood samples were also taken immediately after finishing the race, and during recovery periods (2-hours after and 7-days after). The total number of leukocytes immediately after triathlon race was significantly increased in both groups and in the recovery times (p<.05). The number of neutrophils immediately after triathlon race was also significantly increased in both groups and significantly increased in the recovery times (p<.05). The elite triathletes (EG) recovered after 7 days.
Background: Little is known about the effects of anthropometry on race performance in ultra-endurance athletes. Research question: The investigation of the influence of anthropometric parameters on race performance in ultra-endurance triathletes in the longest triathlon in North America. Type of study: Descriptive field study. Methods: Body mass, body height, length of lower limbs, skinfold thicknesses, circumferences of extremities (as well as calculation of BMI), percent skeletal muscle mass (%SM) and percent body fat (%BF) were determined in the 8 male starters of the Virginia Triple Iron Triathlon 2006 in the USA. This race is the longest triathlon in North America, where athletes have to perform a 11.4 krn swim, 540 km cycle ride and 126.6 km run within 68 hours. The measured and calculated anthropometric parameters were correlated with race performance in order to find factors that influence race performance in ultra-endurance triathletes. Results: In the 5 successful finishers of the race, race time was not significantly influenced by the directly measured anthropometric properties of body height, length of limbs, body mass, average skinfold thickness, and the limb perimeters of thigh, calf and upper arm (p>0.05). Furthermore, no significant influence was observed between race time and the calculated parameters BMI, %BF and %SM (p>0.05). Conclusions: In the Virginia Triple Iron Triathlon 2006, no influence was observed from body mass, body height, length of limbs, skinfold thickness, perimeters of extremities, BMI, %SM and %BF on race performance in the only 5 successful finishers.
Objective: To perform a literature review of the current available data on protein and amino acid supplementation in sports, their efficacy and safety. Data sources: The search was limited to English language citations published in the years 1980- 2007. MEDLINE and PubMed searches were performed in March 2007 on all studies using the Mesh terms: proteins, amino acids, supplement, the desired supplement name and sports/ exercise. Study section: Initially, only randomised controlled clinical trials were included in the analysis. In addition, several recent reviews and relevant meta- analyses were used. Data extraction: A title scan was performed to exclude references that did not include protein supplementation, exercise, or the population's health status was abnormal. Relevant literature was identified, sourced, and reviewed and the selected manuscripts are cited. Data synthesis: Although protein supplementation has been widely discussed in the literature for many years, it was surprising to find the relatively low number of randomised controlled trials that met the inclusion criteria for this review. When the general terms "protein/ amino acids" were used, 43 citations met the criteria; "creatine" yielded 53 citations; "glutamine" 2 citations, and "beta-hydroxy-beta-methylbutyric acid ( HMB)" 9 citations. The bulk of the data suggests that protein requirements are usually met by an iso-caloric, balanced diet, for both endurance and resistance training. Supplementing the athlete's diet with protein or amino acids has not proven beneficial and may even sometimes be harmful. Creatine is currently the only product that has clear scientific support to enhance sporting performance. The timing of protein supplementation may be an important factor in trying to achieve anabolic effects. Conclusions: The use of protein supplements for the healthy, noncompetitive adult engaged in recreational sports is usually not warranted. There are only limited data to support protein supplementation in competitive sports. There is some evidence supporting the use of creatine and possibly HMB as ergogenic aids in specific situations. Further research is needed before definitive recommendations can be made on the type, timing and effectiveness of protein supplements.
Percent of Smoking, Protein Use and Creatine Supplementation among AS non-users and Users
Percent of Alcohol Use among AS non-users and Users
Background: Non- medical anabolic steroid (AS) use in non-professional athletes is an increasingly recognized public health problem in Europe and the United States but poorly studied in the Middle East. Research question: The aim of this study is to assess the prevalence and determinants of anabolic steroid use amongst adult fitness centre attendees in the Greater Beirut area, Lebanon. Type of study: A cross-sectional study design was adopted. Methods: Subjects: The targeted population included all gym attendees in Greater Beirut aged 18 or above. Professional or career athletes competing in organized sports were excluded. Questionnaire: A questionnaire was used to survey participants on demographic information, history of anabolic steroid usage and possible determinants of use. Sampling: A list of 53 fitness centres in the Greater Beirut area was identified. Thirty-three gyms agreed to permit access to their centres. Trained research assistants distributed the questionnaire to all gym attendees on arrival, during equally selected day and evening intervals. A total of 523 gym attendees completed the survey. Results: The prevalence of any history of anabolic steroid use was 10.7%. The majority of users (78.2%) were aware of the adverse health effects. The main reason for usage reported was body image enhancement (82.0%). Demographic factors associated with anabolic steroid use were: male gender, separated/divorced status and full-time employment. Conclusion: Non-medical anabolic steroid use is a public health concern in Lebanon that should be addressed by monitoring AS use in health clubs and with educational programs aimed at high-risk groups, health practitioners and health clubs that not only focus on risk awareness but also on media literacy and body image attitudes. © 2014, International Federation of Sports Medicine. All rights reserved.
Top-cited authors
Del P. Wong
  • Hong Kong Metropolitan University
Karim Chamari
  • Aspetar - Qatar Orthopaedic and Sports Medicine Hospital
Dellal A
  • FIFA centre of excellence, Santy clinic, Lyon, France
Wassim Moalla
  • High Institute of Sport and Physical Education, University of Sfax, Tunisia
Mike Ian Lambert
  • University of Cape Town