SportScotland Institute of Sport

Stirling, United Kingdom

SportScotland Institute of Sport

Stirling, United Kingdom
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McGinley C.,Victoria University of Melbourne | McGinley C.,Sportscotland Institute of Sport | Bishop D.J.,Victoria University of Melbourne
American Journal of Physiology - Regulatory Integrative and Comparative Physiology | Year: 2017

The removal of protons (H+) pro duced during intense exercise is important for skeletal muscle function, yet it remains unclear how best to structure exercise training to improve muscle pH regulation. We investigated whether 4 wk of work-matched sprint-interval trining (SIT), performed 3 days/wk, with either 1 (Rest-1; n = 7) or 5 (Rest-5; n = 7) min of rest between sprints, influenced adaptations in acid/base transport protein content, nonbicarbonate muscle buffer capacity (βmin vitro), and exercise capacity in active women. Following 1 wk of posttesting, comprising a biopsy, a repeated-sprint ability (RSA) test, and a graded-exercise test, maintenance of adaptations was then studied by reducing SIT volume to 1 day/wk for a further 5 wk. After 4 wk of SIT, there was increased protein abundance of monocarboxylate transporter (MCT)-1, sodium/ hydrogen exchanger (NHE)-1, and carbonic anhydrase (CA) XIV for both groups, but rest interval duration did not influence the adaptive response. In contrast, greater improvements in total work performed during the RSA test after 4 wk of SIT were evident for Rest-5 compared with Rest-1 (effect size: 0.51; 90% confidence limits ±0.37), whereas both groups had similarly modest improvements VO2peak. When training volume was reduced to 1 day/wk, enhanced acid/base transport protein abundance was maintained, although NHE1 content increased further for Rest-5 only. Finally, our data support intracellular lactate as a signaling molecule for inducing MCT1 expression, but neither lactate nor H+ accumulation appears to be important signaling factors in MCT4 regulation. © 2017 the American Physiological Society.

Ditroilo M.,University of Hull | Smith I.J.,University of Stirling | Fairweather M.M.,Sportscotland Institute of Sport | Hunter A.M.,University of Stirling
Journal of Electromyography and Kinesiology | Year: 2013

Tensiomyography (TMG) is a technique utilised to measure mechanical and contractile properties of skeletal muscle. Aim of this study was to assess long-term stability of TMG across a variety of muscle conditions. Gastrocnemius Medialis of 21 healthy males was measured using TMG in rested conditions, after a warm-up, after a maximal voluntary contraction and after a fatigue protocol. Participants were re-tested on a second occasion 4. weeks apart. Among the parameters examined, Contraction Time, Sustain Time and Delay time exhibited a good level of absolute reliability (CV = 3.8-9.4%) and poor to excellent level of relative reliability (ICC = 0.56-0.92). On the other hand, relative reliability was good to excellent for muscle Displacement (ICC = 0.86-0.96), whereas its level of absolute reliability was questionable (CV = 8.0-14.8%). Minimum detectable change was less than 20% in most conditions for the aforementioned parameters. Half-relaxation Time yielded overall insufficient reliability. In general, the level of reliability tended to increase after the maximal voluntary contraction and the fatigue protocol were administered, probably because of more controlled conditions preceding the measurement. Information about the long-term stability of TMG across different muscle conditions is essential when intervention studies are undertaken with an exercising population, particularly athletes. © 2013 Elsevier Ltd.

Boyd D.A.,University of Edinburgh | Boyd D.A.,SportScotland Institute of Sport | Donald N.,SportScotland Institute of Sport | Balshaw T.G.,Loughborough University | Balshaw T.G.,University of Stirling
Journal of Strength and Conditioning Research | Year: 2014

The purpose of this study was to compare acute countermovement jump (CMJ) responses after functional isometric (FI) and dynamic half (DH) squats. Ten strength-trained males (relative full back squat 1 repetition maximum [1RM]: 1.9 ± 0.2) participated in a randomized crossover design study. On 2 separate days, participants performed baseline CMJs followed by either FI or DH squats loaded with 150% of full back squat 1RM. Further CMJs were performed between 2 and 11 minutes after FI or DH squats. Kinematic and kinetic CMJ variables were measured. There were no differences observed between conditions when peak CMJ variables after FI or DH squats were compared with baseline values (p > 0.05). Countermovement jump time effects (p ≤ 0.05) were observed after squats. Increases in peak force (p ≤ 0.05; FI: 3.9%, range: 20.9 to 9.1%; DH: 4.2%, range: 0.0-11.5%) and decreases in peak power (p ≤ 0.05; FI: -0.4%, range: 25.1 to 4.0%; DH: 21.1%, range: 26.6 to 2.9%) occurred for combined condition data. Positive correlations between lower-body strength and the extent or timing of acute CMJ responses were not detected (p > 0.05). Because of the apparent lack of additive acute CMJ responses, the use of conventional DH squat protocols should be considered rather than FI squats in precompetition and training situations. Furthermore, the establishment of individual FI and DH squat protocols also seems to be necessary, rather than relying on relative lowerbody strength to predict the nature of acute CMJ responses. © 2014 National Strength and Conditioning Association.

Park J.L.,University of Stirling | Fairweather M.M.,Sportscotland Institute of Sport | Donaldson D.I.,University of Stirling
Neuroscience and Biobehavioral Reviews | Year: 2015

In the high stakes world of International sport even the smallest change in performance can make the difference between success and failure, leading sports professionals to become increasingly interested in the potential benefits of neuroimaging. Here we describe evidence from EEG studies that either identify neural signals associated with expertise in sport, or employ neurofeedback to improve performance. Evidence for the validity of neurofeedback as a technique for enhancing sports performance remains limited. By contrast, progress in characterizing the neural correlates of sporting behavior is clear: frequency domain studies link expert performance to changes in alpha rhythms, whilst time-domain studies link expertise in response evaluation and motor output with modulations of P300 effects and readiness potentials. Despite early promise, however, findings have had relatively little impact for sports professionals, at least in part because there has been a mismatch between lab tasks and real sporting activity. After selectively reviewing existing findings and outlining limitations, we highlight developments in mobile EEG technology that offer new opportunities for sports neuroscience. © 2015 The Authors.

Hunter A.M.,University of Stirling | Galloway S.D.R.,University of Stirling | Smith I.J.,University of Stirling | Tallent J.,Northumbria University | And 4 more authors.
Journal of Electromyography and Kinesiology | Year: 2012

Exercise induced muscle damage (EIMD) impairs maximal torque production which can cause a decline in athletic performance and/or mobility. EIMD is commonly assessed by using maximal voluntary contraction (MVC), creatine kinase (CK) and muscle soreness. We propose as an additional technique, tensiomyography (TMG), recently introduced to measure mechanical and muscle contractile characteristics. The purpose of this study was to determine the validity of TMG in detecting changes in maximal torque following EIMD. Nineteen participants performed eccentric elbow flexions to achieve EIMD on the non- dominant arm and used the dominant elbow flexor as a control. TMG parameters, MVC and rate of torque development (RTD) were measured prior to EIMD and repeated for another six consecutive days. Creatine kinase, muscle soreness and limb girth were also measured during this period. Twenty four hours after inducing EIMD, MVC torque, RTD and TMG maximal displacement had significantly (p< 0.01) declined by 37%, 44% and 31%, respectively. By day 6 MVC, RTD and TMG recovered to 12%, 24% and 17% of respective pre-EIMD values. In conclusion, as hypothesised TMG maximal displacement significantly followed other standard EIMD responses. This could therefore be useful in detecting muscle damage from impaired muscle function and its recovery following EIMD. © 2012 Elsevier Ltd.

Ditroilo M.,University College Dublin | Hunter A.M.,University of Stirling | Haslam S.,University of Stirling | Haslam S.,Sportscotland Institute of Sport | De Vito G.,University College Dublin
Physiological Measurement | Year: 2011

Portable tensiomyography (TMG) and myotonometry (MMT) devices have been developed to measure mechanical and contractile properties of skeletal muscle. The aim of this study was to explore the sensitivity of the aforementioned techniques in detecting a change in passive mechanical properties of the biceps femoris (BF) muscle as a result of change in knee joint angle (i.e. muscle length). BF responses were assessed in 16 young participants (23.4 ± 4.9 years), at three knee joint angles (0°, 45° and 90°), for maximal isometric torque (MIT) along with myo-electrical activity. Contractile and mechanical properties were measured in a relaxed state. Inter-day reliability of the TMG and MMT was also assessed. MIT changed significantly (p < 0.01) across the three angles, so did stiffness and other parameters measured with MMT (p < 0.01). Conversely, TMG could detect changes only at two knee angles (0° and 45°, p < 0.01), when there is enough tension in the muscle. Reliability was overall insufficient for TMG whilst absolute reliability was excellent (coefficient of variation < 5%) for MMT. The ability of MMT more than TMG to detect an inherent change in stiffness can be conceivably exploited in a number of clinical/therapeutic applications that have to do with unnatural changes in passive muscle stiffness. © 2011 Institute of Physics and Engineering in Medicine.

Dempster S.,Coventry University | Britton R.,Coventry University | Murray A.,SportScotland Institute of Sport | Costa R.J.S.,Monash University
International Journal of Sport Nutrition and Exercise Metabolism | Year: 2013

The aims of this study were to assess the dietary intake and monitor self-reported recovery quality and clinical symptomology of a male ultra-endurance runner who completed a multiday ultra-endurance running challenge covering 4,254 km from North Scotland to the Moroccan Sahara desert over 78 consecutive days. Food and fluid intakes were recorded and analyzed through dietary analysis software. Body mass (BM) was determined before and after running each day, and before sleep. Clinical symptomology and perceived recovery quality were recorded each day. Whole blood hemoglobin and serum ferritin were determined before and after the challenge. Total daily energy (mean ± SD: 23.2 ± 3.2MJ·day-1) and macronutrient intake (182 ± 31g·day-1 protein, 842 ± 115g·day-1 carbohydrate, 159 ± 55 g·day-1 fat) met consensus nutritional guidelines for endurance performance. Total daily water intake through foods and fluids was 4.8 ± 2.0L·day-1. Water and carbohydrate intake rates during running were 239 ± 143ml·h-1 and 56 ± 19g·h-1, respectively. Immediately after running, carbohydrate and protein intakes were 1.3 ± 1.0g·kg BM-1 and 0.4 ± 0.2g·kg BM-1, respectively. Daily micronutrient intakes ranged from 109 to 662% of UK RNIs. Prerunning BM was generally maintained throughout. Overall exercise-induced BM loss averaged 0.8 ± 1.0%; although BM losses of ≥ 2% occurred in the latter stages, a reflection of the warmer climate. Varying degrees of self-reported perceived recovery quality and clinical symptomology occurred throughout the challenge. This case study highlights oscillations in dietary habits along 78 consecutive days of ultra-endurance running, dependent on changes in ambient conditions and course topography. Nevertheless, nutrition and hydration status were maintained throughout the challenge. Despite dietary iron intake above RNI and iron supplementation, this alone did not prevent deficiency symptoms. © 2013 Human Kinetics, Inc.

Gibson N.,Heriot - Watt University | White J.,Heriot - Watt University | Neish M.,University of Edinburgh | Murray A.,Sportscotland Institute of Sport
International Journal of Sports Physiology and Performance | Year: 2013

Purpose: The study aimed to assess whether exposure to ischemic preconditioning (IPC) in a trained population would affect land-based maximal sprinting performance over 30 m. Methods: Twenty-five well-trained participants regularly involved in invasion-type team-sport events were recruited to take part in a randomized crossover study design. Participants underwent both an IPC and a placebo treatment involving 3 periods of 5-min occlusion applied unilaterally (3 × 5-min occlusion to each leg) at either 220 mmHg or 50 mmHg, respectively. Each period of occlusion was followed by 5 min of reperfusion. After treatment, 3 maximal sprints over a distance of 30 m were undertaken from a standing start interspersed with 1-min recovery. Split times were recorded at 10, 20, and 30 m. Results: No significant effects of the IPC treatment were observed on sprint speed (P < .05) at any of the split timings; however, a small and negative effect was observed in female participants. Calculated effect sizes of the treatment were found to be trivial (<0.2). Conclusions: Results from the current study suggest there to be no benefit to team-sport players in using IPC as a means of enhancing sprint performance over a distance of 30 m. While IPC has been shown to be beneficial to sprint activities in other sports such as swimming, further research is required to elucidate whether this is the case over distances associated with land-based events in track and field or in events reliant on repeated-sprint ability. © 2013 Human Kinetics, Inc.

Gibson N.,Heriot - Watt University | Mahony B.,University of Edinburgh | Tracey C.,University of Edinburgh | Fawkner S.,University of Edinburgh | Murray A.,sportscotland institute of sport
Journal of Sports Sciences | Year: 2015

Abstract: This study investigated whether ischemic preconditioning (IPC) in a trained population affected repeated sprint performance. A secondary aim was to assess responses according to gender. Sixteen (nine females and seven males) well trained team sport athletes took part in a randomised crossover study design. Participants underwent an IPC and placebo treatment involving three periods of 5 min occlusion applied unilaterally (3 × 5 min occlusion to each leg) at either 220 mmHg or 50 mmHg. Each period of occlusion was followed by 5 min reperfusion. Following treatment 5 × 6 s maximal effort sprints were undertaken on a cycle ergometer against 7.5% body mass, each interspersed by 24 s recovery. Measured parameters included peak power, total power, percentage decrement, post-exercise blood lactate and ratings of perceived exertion. Nor within subject main effect for IPC was observed, neither was there an interaction effect with gender. Effect sizes were trivial (ES < 0.2) with the exception of a moderate (ES < 1.2) change in post-exercise blood lactate in the female cohort (1.6 ± 0.4 mmol−1 lower following IPC). Results suggest no benefit to team sport players in utilising IPC as a means of enhancing repeated sprint performance. A lower blood lactate response in female participants following IPC may suggest improved blood flow through vasodilation. © 2014, © 2014 Taylor & Francis.

Murray A.,SportScotland Institute of Sport | Costa R.J.S.,Coventry University
BMC Medicine | Year: 2012

It is recognised that regular physical activity and a high level of fitness are powerful predictors of positive health outcomes. There is a long and rich history of significant feats of human endurance with some, for example, the death of the first marathon runner, Pheidippides, associated with negative health outcomes.Early studies on endurance running used X-ray and interview techniques to evaluate competitors and comment on performance. Since then, comparatively few studies have looked at runners competing in distances longer than a marathon. Those that have, tend to show significant musculoskeletal injuries and a remarkable level of adaptation to this endurance load.The TransEurope Footrace Project followed ultra-endurance runners aiming to complete 4,500 Km of running in 64 days across Europe. This pioneering study will assess the impact of extreme endurance on human physiology; analysing musculoskeletal and other tissue/organ injuries, and the body's potential ability to adapt to extreme physiological stress. The results will be of interest not only to endurance runners, but to anyone interested in the limits of human performance.Please see related article: © 2012 Murray and Costa; licensee BioMed Central Ltd.

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