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Dive into the research topics where Stuart Semple is active.

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Featured researches published by Stuart Semple.


British Journal of Sports Medicine | 2005

Influence of ultra-endurance exercise on immunoglobulin isotypes and subclasses.

Andrew J. McKune; Ll Smith; Stuart Semple; Ahmed A. Wadee

Background: Strenuous exercise is associated with tissue damage. This activates the innate immune system and local inflammation. Interaction between innate and adaptive immunity is essential for maintaining health, suggesting that the adaptive immune system may also be altered by exercise. Objectives: To determine exercise induced changes in the adaptive immune system by measuring the immunoglobulin isotype and subclass response to an ultra-marathon. Methods: Venepuncture was performed on 11 experienced volunteers (six men, five women; mean (SD) age 43 (9.8) years) 24 hours before the projected finishing time and immediately after and 3, 24, and 72 hours after an ultra-marathon (90 km). Serum was stored at −80°C. IgM, IgD, IgA, IgG, IgG1, 2, 3, and 4, and total IgE were measured. Results: The following immunoglobulins were significantly (p⩽0.05) altered after the race: IgD, immediately (−51%) and 24 hours (−41%) after; IgM 24 hours after (−23%); total IgG immediately after (+12%). There were no reports of symptoms of upper respiratory tract infections after the ultra-marathon. Conclusions: In experienced ultra-endurance runners, alterations in immunoglobulin concentrations after a race suggest an enhanced immune response, including isotype switching, interactions with the innate immune system, and a secondary antibody response. These alterations may have a role in the maintenance of subject health after an ultra-marathon.


British Journal of Sports Medicine | 2006

Serum concentrations of C reactive protein, α1 antitrypsin, and complement (C3, C4, C1 esterase inhibitor) before and during the Vuelta a Espańa

Stuart Semple; Ll Smith; Andrew J. McKune; J Hoyos; Barbara Mokgethwa; A. F. San Juan; Alejandro Lucia; Ahmed A. Wadee

Objectives: To determine serum concentrations of proinflammatory (C reactive protein, complement C3 and C4) and anti-inflammatory (α1 antitrypsin, C1 esterase inhibitor (C1-INH)) acute phase proteins in elite cyclists before and during a three week cycle tour. Methods: Seventeen professional cyclists participating in the Vuelta a Espańa volunteered for the study. Their mean (SD) physical characteristics were: age 28 (1) years; height 1.7 (0.06) m; weight 65 (7) kg; body fat 7.6 (0.8)%; Vo2max 75.3 (2.3) ml/kg/min. Venepuncture was performed on each subject 24 hours before the tour began (T0), on day 11 (the first rest day; T1) and day 21 (the second to last stage of the tour; T2). Samples at T1 and T2 were taken about 17 hours after the previous stage. Analysis of variance was used to determine changes over time. Where significance was found, a Tukey post hoc test was performed. Results: C reactive protein concentrations were consistently within the normal range, although there was a 228%, non-significant increase at T1. C3 concentrations fell within the normal range at all times assessed. C4 concentrations before the race were within the normal range and were significantly increased 10 days (T1) into the race. C1-INH concentrations did not change significantly throughout the race. α1 Antitrypsin concentration before the race was at the lower end of the normal range and was only significantly raised at T2. Conclusions: Although not as pronounced as those reported in marathon/ultramarathon runners, elite cyclists participating in a three week cycle tour experienced increases in selected proinflammatory and anti-inflammatory acute phase proteins, indicating an acute phase/inflammatory response. It is tenable that the increase in α1 antitrypsin and C1-INH (anti-inflammatory mediators) at T2 served to attenuate the acute phase/inflammatory response. The lower than normal resting concentrations of the acute phase proteins supports the notion that chronic aerobic exercise induces an anti-inflammatory state.


Biology of Sport | 2012

ACUTE EXERCISE-INDUCED MUSCLE INJURY

Andrew J. McKune; Stuart Semple; E.M. Peters-Futre

While much research has recently been focussing on the chronic effects of overtraining, the acute damaging effects of individual eccentric exercise bouts on muscle remain of interest and underlie long-term training effects. Systemic markers of muscle damage are limited in terms of sensitivity and reliability. A clearer insight into the extent of the damage and mechanisms involved are being obtained from ultrastructural, functional and molecular examination of the muscle. There are currently indications that while the initial muscle damage may appear to have negative consequences in the short term, intense eccentric exercise appears to initiate a remodelling process and promote favourable adaptation of muscle following training, which has applications for promoting health, rehabilitation and sports performance.


Lipids in Health and Disease | 2012

Statin therapy, myopathy and exercise--a case report

Stuart Semple

In a bid to reduce the morbidity and mortality associated with coronary artery disease, statin therapy has become a cornerstone treatment for patients with dyslipideamia. Statins, or HMG-CoA reductase inhibitors, are effective in blocking hepatic synthesis of cholesterol and are generally regarded as safe. Although rare, severe adverse side effects such as rhabdomyolysis have been reported, however, the more common complaint from patients is that related to myopathy. There is also mounting evidence that exercise may exacerbate these side effects, however the mechanisms are yet to be fully defined and there is controversy regarding the role that inflammation may play in the myopathy. This paper reports a patients experience during 6 months of simvastatin therapy and provides some insight into the white cell count (inflammation) following two bouts of moderate intensity exercise before and during statin therapy. It also highlights the need for rehabilitation practitioners to be aware of the adverse effects of statins in exercising patients.


British Journal of Sports Medicine | 2006

Immunoglobulin responses to a repeated bout of downhill running

Andrew J. McKune; Ll Smith; Stuart Semple; Barbara Mokethwa; Ahmed A. Wadee

Objective: To examine the effect of downhill running on immunoglobulin responses. Method: Eleven untrained men performed 2 × 60 minute bouts of downhill running (−13.5% gradient), at a speed eliciting 75% of their V̇o2peak on a level grade. Two runs were spaced 14 days apart. Serum samples were collected before, after, and every hour for 12 hours and every 24 hours for six days. Serum total creatine kinase and immunoglobulin isotypes and subclasses were measured, and results were analysed using a repeated measures analysis of variance (12 hour period, 2 × 14; 24 hour intervals, 2 × 6, p⩽0.05). Results: There was a significant interaction effect for creatine kinase (activity lower after run 2 than after run 1, 6–24 h) and exercise effect, with the serum concentrations of IgG1, IgG2, IgG4, and IgE lower, and IgM higher, after run 2. Conclusion: Lower concentrations of IgG1, IgG2, and IgE after run 2 may reflect a dampened autoimmune inflammatory response to autoantigens and enhanced autoantigen clearance mediated by the upregulation of IgM.


Journal of Exercise Science & Fitness | 2015

Exercise therapy for human immunodeficiency virus/AIDS patients: Guidelines for clinical exercise therapists

Jeanne Grace; Stuart Semple; Susan Combrink

Human immunodeficiency virus (HIV) has infected > 60 million people since its discovery and 30 million people have died since the pandemic began. Antiretroviral therapy has transformed HIV infection from an acute to a chronic disease, increasing life expectancy but also adding to the potential side effects associated with drug therapy and the comorbidity accompanying longevity. Exercise can play a valuable role in the management of HIV/AIDS patients by addressing various symptoms and improving their quality of life, but the optimum mode, intensity, frequency, and duration of exercise that take the different clinical stages of the disease into consideration are inadequately known. Searches of Medline, Embase, Science Citation Index, CINAHL database, HealthSTAR, PsycINFO, Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews, Physiotherapy Evidence Database (PEDro), and SPORTDiscus were conducted between 2000 and January 2014. Searches of published and unpublished abstracts were conducted, as well as a hand search of reference lists and tables of contents of relevant journals and books. Identified studies were reviewed for methodological quality. A total of 33 studies met the inclusion criteria. Most studies failed to indicate the optimum type (mode), intensity, frequency, and duration of aerobic and progressive resistive exercise prescribed to HIV-infected individuals in relation to the different clinical stages of the disease. The purpose of this review is to provide evidence-based recommendations after revision of exercise guidelines for HIV patients, by highlighting practical guidelines that clinical exercise therapists should consider when prescribing exercise for patients in different stages of the disease.


PeerJ | 2016

A pilot study examining the effects of low-volume high-intensity interval training and continuous low to moderate intensity training on quality of life, functional capacity and cardiovascular risk factors in cancer survivors

Kellie Toohey; Kate L. Pumpa; Leonard F Arnolda; Julie Cooke; Desmond Yip; Paul Craft; Stuart Semple

Purpose The aim of this study was to evaluate the effects of low-volume high-intensity interval training and continuous low to moderate intensity training on quality of life, functional capacity and cardiovascular disease risk factors in cancer survivors. Methods Cancer survivors within 24 months post-diagnosis were randomly assigned into the low-volume high-intensity interval training group (n = 8) or the continuous low to moderate intensity training group (n = 8) group for 36 sessions (12 weeks) of supervised exercise. The low-volume high-intensity interval training (LVHIIT) group performed 7 × 30 s intervals (≥85% maximal heart rate) and the continuous low to moderate intensity training (CLMIT) group performed continuous aerobic training for 20 min (≤55% maximal heart rate) on a stationary bike or treadmill. Results Significant improvements (time) were observed for 13 of the 23 dependent variables (ES 0.05–0.61, p ≤ 0.05). An interaction effect was observed for six minute walk test (18.53% [32.43–4.63] ES 0.50, p ≤ 0.01) with the LVHIIT group demonstrating greater improvements. Conclusion These preliminary findings suggest that both interventions can induce improvements in quality of life, functional capacity and selected cardiovascular disease risk factors. The LVHIIT program was well tolerated by the participants and our results suggest that LVHIIT is the preferred modality to improve fitness (6MWT); it remains to be seen which intervention elicits the most clinically relevant outcomes for patients. A larger sample size with a control group is required to confirm the significance of these findings.


American Journal of Human Biology | 2014

Salivary cortisol and α-amylase responses to repeated bouts of downhill running

Andrew J. McKune; Christopher W. Bach; Stuart Semple; Barry J. Dyer

To determine the hypothalamic‐pituitary‐adrenal (HPA) axis and sympathoadrenal (SA) system response to repeated bouts of downhill running.


Strength and Conditioning Journal | 2013

Core muscle activation and activity throughout the different phases of the golf swing: A literature review

Henriëtte V. Loock; Jeanne Grace; Stuart Semple

ABSTRACT THE GOLF SWING REQUIRES SPECIFIC MUSCLE CONTRACTION. THE PURPOSE OF THIS STUDY IS TO COMPILE A STRUCTURED LITERATURE REVIEW OF CORE MUSCLE ACTIVITY WITHIN DIFFERENT PHASES OF THE GOLF SWING. A LITERATURE SEARCH WAS CONDUCTED TO CAPTURE ALL ARTICLES APPLICABLE. A DESCRIPTIVE ANALYSIS WAS UNDERTAKEN. THE SEARCH RESULTED IN 150 ARTICLES, 59 OF WHICH MET INCLUSION CRITERIA; 16 WERE CONCERNED WITH CORE MUSCLES WITHIN DIFFERENT PHASES OF THE GOLF SWING. AVAILABLE RESEARCH IS LIMITED TO SPECIFIC MUSCLE GROUPS AND ONLY ADDRESSES CERTAIN PHASES OF THE GOLF SWING. NO DATA PORTRAYS THE ACTIVITY OF CORE MUSCLES DURING DIFFERENT PHASES OF THE GOLF SWING.


Biology of Sport | 2014

Repeated bouts of eccentrically biased endurance exercise stimulate salivary IgA secretion rate

Andrew J. McKune; Dorota E. Starzak; Stuart Semple

To determine the salivary secretory immunoglobulin A (sIgA) response to repeated bouts of unaccustomed, downhill running (eccentrically biased) and examine potential protective immunological adaption from a repeated bout effect. Eleven active but untrained males (age: 19.7±0.4 years; VO2peak: 47.8± 3.6 ml · kg−1 · min −1) performed two 60 min bouts (Run 1 and Run 2) of downhill running (−13.5% gradient), separated by 14 days, at a speed eliciting 75% of their VO2peak on a level grade. Saliva samples were collected before (baseline), immediately post exercise (IPE), and every hour for 12 h and every 24 h for 6 days after each run. Salivary sIgA concentration was measured and sIgA secretion rate was calculated. Results were analysed using repeated measures ANOVA (12 h period: 2x14; 24 h intervals: 2x7; p ≤ 0.05) with Tukey post-hoc tests where appropriate. Results are reported as means ± SE. There was a significant (p < 0.0001) interaction effect for sIgA secretion rate, IPE, with higher values after Run 2, as well as a significant (p < 0.01) time effect with elevated levels IPE and between 24 h and 144 h. There was a run effect (p < 0.0001), with the sIgA secretion rate significantly higher after Run 2. Repeated bouts of unaccustomed, eccentrically biased exercise induced alterations in the salivary sIgA secretion rate. This may serve as a protective mucosal adaptation to exercise-induced tissue damage.

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Ll Smith

Tshwane University of Technology

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Ahmed A. Wadee

University of the Witwatersrand

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N Neveling

Tshwane University of Technology

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Julie Cooke

University of Canberra

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