Leeder J.,English Institute of Sport |
Glaister M.,St. Mary's College |
Pizzoferro K.,University of Surrey |
Dawson J.,University of Surrey |
Pedlar C.,St. Mary's College
Journal of Sports Sciences | Year: 2012
Sleep is known to be an important component of recovery from training, yet little is known about the quality and quantity of sleep achieved by elite athletes. The aim of the present study was to quantify sleep in elite athletes using wristwatch actigraphy. Individual nights of sleep from a cohort of Olympic athletes (n = 47) from various sports were analysed and compared to non-athletic controls (n = 20). There were significant differences between athletes and controls in all measures apart from 'time asleep' (p = 0.27), suggesting poorer characteristics of sleep in the athlete group. There was a significant effect of gender on 'time awake' (mean difference: 12 minutes higher in males; 95% likely range: 3 to 21 minutes) and 'sleep efficiency' (mean difference: 2.4 lower in males; 95% likely range: 0.1 to 4.8). Athletes showed poorer markers of sleep quality than an age and sex matched non-athletic control group (Sleep efficiency: 80.6 ± 6.4% and 88.7 ± 3.6%, respectively. Fragmentation Index: 36.0 ± 12.4 and 29.8 ± 9.0, respectively) but remained within the range for healthy sleep. This descriptive study provides novel data for the purpose of characterising sleep in elite athletes. © 2012 Copyright Taylor and Francis Group, LLC.
Mettler S.,University of Birmingham |
Mettler S.,ETH Zurich |
Mitchell N.,English Institute of Sport |
Tipton K.D.,University of Birmingham
Medicine and Science in Sports and Exercise | Year: 2010
Purpose: To examine the influence of dietary protein on lean body mass loss and performance during short-term hypoenergetic weight loss in athletes. Methods: In a parallel design, 20 young healthy resistance-trained athletes were examined for energy expenditure for 1 wk and fed a mixed diet (15% protein, 100% energy) in the second week followed by a hypoenergetic diet (60% of the habitual energy intake), containing either 15% (∼1.0 g•kg) protein (control group, n = 10; CP) or 35% (∼2.3 g•kg) protein (high-protein group, n = 10; HP) for 2 wk. Subjects continued their habitual training throughout the study. Total, lean body, and fat mass, performance (squat jump, maximal isometric leg extension, one-repetition maximum (1RM) bench press, muscle endurance bench press, and 30-s Wingate test) and fasting blood samples (glucose, nonesterified fatty acids (NEFA), glycerol, urea, cortisol, free testosterone, free Insulin-like growth factor-1 (IGF-1), and growth hormone), and psychologic measures were examined at the end of each of the 4 wk. Results: Total (-3.0 ± 0.4 and-1.5 ± 0.3 kg for the CP and HP, respectively, P = 0.036) and lean body mass loss (-1.6 ± 0.3 and-0.3 ± 0.3 kg, P = 0.006) were significantly larger in the CP compared with those in the HP. Fat loss, performance, and most blood parameters were not influenced by the diet. Urea was higher in HP, and NEFA and urea showed a group × time interaction. Fatigue ratings and "worse than normal" scores on the Daily Analysis of Life Demands for Athletes were higher in HP. Conclusions: These results indicate that ∼2.3 g•kg or ∼35% protein was significantly superior to ∼1.0 g•kg or ∼15% energy protein for maintenance of lean body mass in young healthy athletes during short-term hypoenergetic weight loss. Copyright © 2010 by the American College of Sports Medicine.
Horsley I.G.,English Institute of Sport |
Fowler E.M.,University of Salford |
Rolf C.G.,Karolinska University Hospital
Journal of Orthopaedic Surgery and Research | Year: 2013
Background: In the literature, little is known about the level and pattern of rugby injuries. Of the shoulder injuries reported, 51% of these are caused during a tackle, and 65% of all match injuries affected the shoulder.Objective: The study aims to describe a sport-specific unique intra-articular shoulder pathology of professional rugby players, who presented with persistent pain and dysfunction despite physiotherapeutic treatment and rest.Method: This study is a retrospective analysis set at a university sports medicine clinic. Eighty-seven professional rugby players, referred by their professional medical team since they could no longer play, underwent shoulder arthroscopy between June 2001 and October 2007 due to persistent shoulder pain and dysfunction. All were full-time professional male rugby union and rugby league players. They all had failed conservative treatment for their complaint, and the diagnosis was unclear. Arthroscopic findings were used as a measure of main outcome.Results: The primary mechanism of injury was reported as direct tackling (56%; n = 49) followed in succession by falling onto the arm (10%; n = 8). However, in 30% of the cases, no definite injury could be recalled. The main operative finding was that most patients exhibited multiple shoulder pathologies, with 75% of cases presenting with two or more pathologies. A superior labrum anterior to posterior (SLAP) lesion was evident at arthroscopy in 72 of the 87 cases (83%), while rotator cuff tears were evident in 43% of cases (n = 37). One-third of all cases had a Bankart tear (n = 29), despite none of them reporting previous dislocations, while other labral tears, excluding SLAP tears, to the inferior or posterior labrum were present in 34% (n = 30) of the cohort.Conclusions: Repeated tackling, which is clearly rugby specific, is most likely to be responsible for most of these shoulder injuries, which upon arthroscopic examination, showed signs of mixed pathology. We suggest that an early arthroscopic investigation is valuable in this population in order to confirm treatable diagnosis on the painful shoulder and expedite a safe return to play. © 2013 Horsley et al.; licensee BioMed Central Ltd.
Osborne N.J.,University of Sheffield |
Gatt I.T.,English Institute of Sport
Acupuncture in Medicine | Year: 2010
These case reports describe the short-term benefits of dry needling in shoulder injuries in four international female volleyball athletes during a month-long intense competitive phase, using both replicable subjective and objective measures. Dry needling of scapulohumeral muscles was carried out. Range of movement, strength and pain were assessed before and after treatment, with a functional assessment of pain immediately after playing and overhead activity, using the short form McGill Pain Questionnaire. All scores were improved post-treatment and athletes were able to continue overhead activities. Previous studies have suggested that myofascial trigger points may cause significant functional weakness and reduced range of motion, with referred pain. Trigger point dry needling has been successful in treating athletes with myofascial pain and impingement symptoms but with only subjective improvement and not during a competitive phase. These cases support the use of dry needling in elite athletes during a competitive phase with short-term pain relief and improved function in shoulder injuries. It may help maintain rotator cuff balance and strength, reducing further pain and injury.
Faghy M.A.,University of Derby |
Brown P.I.,University of Derby |
Brown P.I.,English Institute of Sport
European Journal of Applied Physiology | Year: 2014
Purpose: We investigated the effect of carrying a 25 kg backpack upon exercise-induced respiratory muscle fatigue, pulmonary function and physiological and perceptual responses to exercise. Methods: Nineteen healthy males performed 60 min walking at 6.5 km h-1 and 0 % gradient with a 25 kg backpack (load carriage; LC). Following 15 min recovery participants then completed a 2.4 km time trial with the load (LCTT) and on a different day, repeated the trials without the load [control trial (CON) and control time trial (CONTT), respectively]. Respiratory muscle fatigue was determined by the transient change in maximal inspiratory (P Imax) and expiratory (P Emax) pressure prior to and immediately following exercise. Results: P Imax and P Emax were reduced from baseline by 11 and 13 % (P < 0.05), respectively, post-LC but remained unchanged post-CON. Following the time trial P Imax and P Emax were reduced 16 and 19 %, respectively, post-LCTT (P < 0.05) and by 6 and 10 %, respectively (P < 0.05), post-CONTT compared to baseline. Both forced vital capacity and forced expiratory volume in 1 s were reduced by 4 ± 13 and 1 ± 9 %, respectively, during LC when compared to CON. Relative to CON all physiological and perceptual responses were greater in LC, both post-LC and -LCTT (P < 0.01). Time trial performance was faster during CONTT (11.08 ± 1.62 min) relative to LCTT (15.93 ± 1.91 min; P < 0.05). Conclusion: This study provides novel evidence that constant speed walking and time trial exercise with 25 kg thoracic load carriage induces significant inspiratory and expiratory muscle fatigue and may have important performance implications in some recreational and occupational settings. © 2014 Springer-Verlag Berlin Heidelberg.
Ford P.R.,Liverpool John Moores University |
Yates I.,English Institute of Sport |
Williams A.M.,Liverpool John Moores University |
Williams A.M.,University of Sydney
Journal of Sports Sciences | Year: 2010
We examined the practice activities and instructional behaviours employed by 25 youth soccer coaches during 70 different practice sessions. We evaluated the extent to which these activities and behaviours differ from those shown in contemporary research to best facilitate skill acquisition. Nine coaches worked with the under-9 years age group and eight coaches each with the under-13 and under-16 years age groups; nine of those coaches were employed at the elite level, nine at the sub-elite level, and seven at the non-elite level. Coaches had players spend more time in activities that were deemed less relevant to soccer match performance, termed "training form" (e.g. physical training, technique and skills practices), than activities deemed more relevant, termed "playing form" (e.g. small-sided/conditioned games and phase of play activities). Coaches provided high levels of instruction, feedback, and management, irrespective of the activity in which players engaged. Few differences in practice activities and instructional behaviours were reported across skill and age groups, implying the absence of any notable age- or skill-related progression. Findings are discussed with reference to recent research in the areas of skill acquisition, motor learning, and expert performance. © 2010 Taylor & Francis.
Nunan D.,Kingston University |
Howatson G.,Northumbria University |
Van Someren K.A.,English Institute of Sport
Journal of Strength and Conditioning Research | Year: 2010
The purpose of this study was to examine the effects of combined oral b-hydroxy-b-methylbutyrate (HMB) and a-ketoisocaproic acid (KIC) supplementation on indices of exercise-induced muscle damage (EIMD) after an acute bout of eccentric-biased exercise. Fourteen male subjects were allocated to 2 groups: a placebo group (3 g·d-1 corn flour, N = 7) or an HMB + KIC group (3 g·d-1 HMB and 0.3 g·d-1 KIC, N = 7). Supplementation commenced 11 days before a 40-minute bout of downhill running and continued for 3 days post-exercise. Delayed-onset muscle soreness, mid-thigh girth, knee extensor range of motion, serum creatine kinase (CK) activity, and isometric and concentric torque were assessed pre-exercise and at 24, 48, and 72 hours post-exercise. Delayed-onset muscle soreness, CK activity, and isometric and concentric torque all changed over the 72-hour period (p < 0.05); however, HMB + KIC had no significant effect on any of the indices of muscle damage. Although 14 days HMB and KIC supplementation did not attenuate indices of EIMD after an acute bout of unaccustomed eccentric-biased exercise, there was a trend for a more rapid rate of recovery in isometric and isokinetic muscle function. β-hydroxy-β-methylbutyrate and KIC may therefore provide limited benefit in the recovery of muscle function after EIMD in untrained subjects or after unaccustomed exercise. © 2010 National Strength and Conditioning Association.
Lundy B.,English Institute of Sport
International Journal of Sport Nutrition and Exercise Metabolism | Year: 2011
Synchronized swimming enjoys worldwide popularity and has been part of the formal Olympic program since 1984. Despite this, relatively little research has been conducted on participant nutrition practices and requirements, and there are significant gaps in the knowledge base despite the numerous areas in which nutrition could affect performance and safety. This review aimed to summarize current findings and identify areas requiring further research. Uniform physique in team or duet events may be more important than absolute values for muscularity or body fat, but a lean and athletic appearance remains key. Synchronized swimmers appear to have an increased risk of developing eating disorders, and there is evidence of delayed menarche, menstrual dysfunction, and lower bone density relative to population norms. Dietary practices remain relatively unknown, but micronutrient status for iron and magnesium may be compromised. More research is required across all aspects of nutrition status, anthropometry, and physiology, and both sports nutrition and sports medicine support may be required to reduce risks for participants. © 2011 Human Kinetics, Inc.
Hayes M.,University of Brighton |
Castle P.C.,Glaxosmithkline |
Ross E.Z.,English Institute of Sport |
Maxwell N.S.,University of Brighton
International Journal of Sports Physiology and Performance | Year: 2014
To examine the effect of a hot humid (HH) compared with a hot dry (HD) environment, matched for heat stress, on intermittent-sprint performance. In comparison with HD, HH environments compromise evaporative heat loss and decrease exercise tolerance. It was hypothesized that HH would produce greater physiological strain and reduce intermittent-sprint exercise performance compared with HD. Method: Eleven male team-sport players completed the cycling intermittent-sprint protocol (CISP) in 3 conditions, temperate (TEMP; 21.2°C ± 1.3°C, 48.6% ± 8.4% relative humidity [rh]), HH (33.7°C ± 0.5°C, 78.2% ± 2.3% rh), and HD (40.2°C ± 0.2°C, 33.1% ± 4.9% rh), with both heat conditions matched for heat stress. Results: All participants completed the CISP in TEMP, but 3 failed to completed the full protocol of 20 sprints in HH and HD. Peak power output declined in all conditions (P < .05) but was not different between any condition (sprints 1-14 [N = 11]: HH 1073 ± 150 W, HD 1104 ± 127 W, TEMP, 1074 ± 134; sprints 15-20 [N = 8]: HH 954 ± 114 W, HD 997 ± 115 W, TEMP 993 ± 94; P > .05). Physiological strain was not significantly different in HH compared with HD, but HH was higher than TEMP (P < .05). Conclusion: Intermittent-sprint exercise performance of 40 min duration is impaired, but it is not different in HH and HD environments matched for heat stress despite evidence of a trend toward greater physiological strain in an HH environment. © 2014 Human Kinetics, Inc.
Herrington L.,University of Salford |
Horsley I.,English Institute of Sport
Journal of Sport and Health Science | Year: 2014
Background: Shoulder flexion requires an optimal length of the latissimus dorsi muscle in order to allow full lateral rotation of the humerus and upward scapular rotation. If shoulder flexion (in an externally rotated position) is restricted, this may predispose the individual to shoulder pathology. Sports such as swimming and canoeing have increased shoulder injuries and require high levels of latissimus dorsi muscle activity, which may create muscle hypertrophy and increased stiffness, resulting in a loss of muscle length. The objective of this study was to investigate if differences are present in shoulder flexion in internally and externally rotated positions across different sports (swimming, canoeing, and rugby) and a non-sporting control group. Methods: One hundred subjects (40 physically active controls, 25 professional Rugby Union players, 20 elite, national-level canoeists (slalom), and 15 elite, national-level swimmers) participated in this study. Shoulder flexion range of motion was measured using a standard goniometer, with the arm elevated in either full external or internal rotation. Results: A significant difference in shoulder flexion range was observed between canoeists and swimmers, canoeists and controls, rugby players and canoeists, rugby players and swimmers, and controls and swimmers in the external rotation position ( p<0.017), but not between controls and rugby players ( p=0.12). For the internal rotation position, swimmers significantly differed from canoeists, rugby players, and controls ( p<0.017), but there were no significant differences between rugby players, canoeists, and controls ( p<0.07). Conclusion: This study found that the length of the latissimus dorsi differs between sports and controls in accordance with the specific physical demands of their sport. © 2013 Shanghai University of Sport.