Left ventricular speckle tracking-derived cardiac strain and cardiac twist mechanics in athletes : A systematic review and meta-analysis of controlled studies
- Authors: Beaumont, Alexander , Grace, Fergal , Richards, Joanna , Hough, John , Oxborough, David , Sculthorpe, Nicholas
- Date: 2017
- Type: Text , Journal article
- Relation: Sports Medicine Vol. 47, no. 6 (2017), p. 1145-1170
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Exercise-induced responses in salivary testosterone, cortisol, and their ratios in men : A meta-analysis
- Authors: Hayes, Lawrence , Grace, Fergal , Baker, Julien , Sculthorpe, Nicholas
- Date: 2015
- Type: Text , Journal article
- Relation: Sports Medicine Vol. 45, no. 5 (2015), p. 713-726
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- Description: BACKGROUND: Testosterone, cortisol and their ratios may be indicators of anabolic status, but technical issues surrounding blood sampling has limited wider application. The advent of salivary testosterone (sal-T) analysis simplified sample acquisition, resulting in a subsequent rapid increase in the number of published research articles. OBJECTIVE: The objective of this study was to undertake a meta-analysis to determine the effect of acute exercise bouts on post exercise sal-T and salivary cortisol (sal-C) concentrations and their ratio (sal-T:C). DATA SOURCES: Relevant databases such as PubMed, Web of Science, Science Direct and SPORTDiscus were searched up to and including 31 December 2013 for the term 'saliva AND testosterone AND exercise'. STUDY SELECTION: Studies (n = 21) selected from the 933 identified included randomised controlled trials (RCTs; n = 2), uncontrolled trials (UCTs; n = 18) and control trials (CTs; n = 1), all of which had an exercise component characterised as either aerobic, resistance or power training, each with acute sal-T and sal-C measurement obtained within 30 min of exercise bout completion. STUDY APPRAISAL AND SYNTHESIS METHODS: A meta-analysis was conducted on change in sal-T, sal-C and the sal-T:C ratio following exercise using standard difference in means (SDM) and a random effects model. RESULTS: For aerobic, resistance and power exercise, the overall SDMs for sal-T were 0.891, 1.061 and 0.509, respectively; for sal-C, the SDMs were 3.041, 0.773 and 1.200, respectively. For sal-T:C, the SDMs were -2.014, 0.027 and -0.968, respectively. RCTs, UCTs and CTs were separated by subgroup analysis. There were significant differences in overall weighted SDM values for sal-T between RCTs, UCTs and CTs within exercise modes. When examining aerobic exercise interventions, a quantitative interaction of study design was observed. RCTs resulted in a greater SDM than UCTs (1.337 vs. 0.446). Power interventions displayed a qualitative interaction with study design. UCTs where baseline measures were obtained 24 h before exercise had an SDM of -1.128, whereas UCTs where baseline was determined immediately prior to exercise had an SDM of 0.486. The single CT trial had an SDM of 2.260. Resistance exercise interventions were primarily UCTs; however, an observed influence of baseline sampling time whereby immediately pre- and 24 h pre-exercise resulted in differing SDMs. The sole resistance exercise RCTs resulted in the greatest SDM (2.500). CONCLUSION: The current body of evidence regarding acute responses of sal-T to exercise is weak. This meta-analysis identifies varying exercise-dependent effect sizes. Each appear to be greatly influenced by study design and sample timing. There is a need for more RCTs and a standardised methodology for the measurement of salivary hormones in order to better determine the effect of exercise modality.
Aerobic training protects cardiac function during advancing age : A meta-analysis of four decades of controlled studies
- Authors: Beaumont, Alexander , Grace, Fergal , Richards, Joanna , Campbell, Amy , Sculthorpe, Nicholas
- Date: 2019
- Type: Text , Journal article , Review
- Relation: Sports Medicine Vol. 49, no. 2 (2019), p. 199-219
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- Description: Background: In contrast to younger athletes, there is comparatively less literature examining cardiac structure and function in older athletes. However, a progressive accumulation of studies during the past four decades offers a body of literature worthy of systematic scrutiny. Objectives: We conducted a systematic review, meta-analysis and meta-regression of controlled echocardiography studies comparing left ventricular (LV) structure and function in aerobically trained older athletes (> 45 years) with age-matched untrained controls, in addition to investigating the influence of chronological age. Methods: Electronic databases were searched from inception to January 2018 before conducting a random-effects meta-analysis to calculate pooled differences in means, effect size and 95% confidence intervals (CIs). Study heterogeneity was reported using Cochran’s Q and I2 statistic. Results: Overall, 32 studies (644 athletes; 582 controls) were included. Athletes had greater LV end-diastolic diameter (3.65 mm, 95% CI 2.66–4.64), interventricular septal thickness (1.23 mm, 95% CI 0.85–1.60), posterior wall thickness (1.20 mm, 95% CI 0.83–1.56), LV mass (72 g, 95% CI 46–98), LV mass index (28.17 g·m2, 95% CI 19.84–36.49) and stroke volume (13.59 mL, 95% CI 7.20–19.98) (all p < 0.01). Athletes had superior global diastolic function [ratio of early (E) to late (A) mitral inflow velocity (E/A) 0.18, 95% CI 0.13–0.24, p < 0.01; ratio of early (e′) to late (a′) diastolic annular tissue velocity (e′/a′) 0.23, 95% CI 0.06–0.40, p = 0.01], lower A (−8.20 cm·s−1, 95% CI −11.90 to −4.51, p < 0.01) and a′ (−0.72 cm·s−1, 95% CI −1.31 to −0.12, p = 0.02), and more rapid e′ (0.96 cm·s−1, 95% CI 0.05–1.86, p = 0.04). Meta-regression for chronological age identified that athlete–control differences, in the main, are maintained during advancing age. Conclusions: Athletic older men have larger cardiac dimensions and enjoy more favourable cardiac function than healthy, non-athletic counterparts. Notably, the athlete groups maintain these effects during chronological ageing. © 2018, The Author(s).
Strength adaptation to squat exercise is different between Caucasian and South Asian novice exercisers
- Authors: Knox, Allan , Sculthorpe, Nicholas , Baker, Julien , Grace, Fergal
- Date: 2017
- Type: Text , Journal article
- Relation: Research in Sports Medicine Vol. 25, no. 3 (2017), p. 373-383
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- Description: This study compared the progression of muscular strength (MS) adaptation between age-matched Caucasian (CAUC) and South Asian (SOU) men during 6 weeks (3x week-1) of resistance training. MS was determined pre and post intervention by 3-repetition maximum (3RM) strength tests, and data were analysed using repeated measures ANOVA. Pre-intervention upper and lower body 3RM were similar between groups and both upper and lower body 3RM increased in CAUCs (P < .001) and SOUs (P < .001) following resistance training. However, lower body strength adaptation (3RM) was higher in CAUCs compared with SOUs (P = .002). There was a significant group x time interaction in strength progression of the squat exercise (P = 0.03) from session 7 through to 18 (completion). The present study offers novel but provisional data that lower body strength adaptation is slower in SOU than CAUC men despite comparable adaptation to upper body strength.
Validation of a six second cycle test for the determination of peak power output
- Authors: Herbert, Peter , Sculthorpe, Nicholas , Baker, Julien , Grace, Fergal
- Date: 2015
- Type: Text , Journal article
- Relation: Research in Sports Medicine Vol. 23, no. 2 (2015), p. 115-125
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- Description: The present study examined the agreement between peak power output during a standard Wingate anaerobic test (WAnT) and a six second 'all-out' test on a Wattbike Pro. Nine males (40.7 +/- 19.4 yrs, 1.76 +/- 0.03 cm, 82.11 +/- 8.9 kg) underwent three testing protocols on separate days. The protocols consisted 30 second WAnT (WAnT30), a modified WAnT over 6 seconds (WAnT6) and a 6 second peak power test (PPT6). PPT6 was correlated with WAnT30 (r = 0.9; p < 0.001) with a mean bias of 105 W. PPT6 correlated with WAnT6 (r = 0.95; p < 0.001) with a mean bias of 74 W. WAnT6 correlated with WAnT30 (r = 0.99; p < 0.001) with a mean bias of 31 W. There was no difference in time to peak power between any trial. PPT6 resulted in significantly greater power outputs than in WAnT30 and WAnT6 (p < 0.001). We conclude that PPT6 and WAnT6 are valid measures of peak power output compared with WAnT30. This identifies that PPT6 and WAnT6 as short duration 'all-out' tests that have practical applications for researchers and coaches who wish to assess peak power output without the fatiguing effects associated with a standard WAnT.
Salivary testosterone and cortisol measurement in sports medicine : A narrative review and user's guide for researchers and practitioners
- Authors: Hayes, Lawrence , Sculthorpe, Nicholas , Cunniffe, B. , Grace, Fergal
- Date: 2016
- Type: Text , Journal article , Review
- Relation: International Journal of Sports Medicine Vol. 37, no. 13 (2016), p. 1007-1018
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- Description: Since the initial reporting of salivary hormone measurements in marathon runners in the early 1980s, the practice of utilizing salivary testosterone (T) and cortisol (C) to reflect acute and rhythmic changes to their systemic counterparts has gained considerable momentum. However, substantial variability exists between studies with respect to methodological protocols, laboratory techniques, and interpretation of study findings. These differences can directly influence the salivary hormone values, thus hampering interpretation, limiting cross-study comparison, and constraining the generalizability of individual study findings. This article examines the current body of literature before proposing a sequence of practical guidelines to minimize sample variability in salivary hormone research. The guidelines are grouped into 3 major categories that limit comparison between studies; A) study design, B) sample acquisition and biological variation, and C) technical and analytical error. To achieve this, the present article critically appraises research employing salivary T and C measurements, identifies potential sources of error before proposing appropriate methodological considerations for researchers and practitioners wishing to obtain T and C measurement from saliva. BASI AA, 1980, JOURNAL OF LABORATORY AND CLINICAL MEDICINE, V96, P544
Does chronic exercise attenuate age-related physiological decline in males?
- Authors: Hayes, Lawrence , Grace, Fergal , Sculthorpe, Nicholas , Herbert, Peter , Kilduff, Liam , Baker, Julien
- Date: 2013
- Type: Text , Journal article
- Relation: Research in Sports Medicine Vol. 21, no. 4 (2013), p. 343-354
- Full Text: false
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- Description: Alteration in body composition, physical function, and substrate metabolism occur with advancing age. These changes can be attenuated by exercise. This study evaluated whether master athletes (MA [n = 20]) would have improved exercise capabilities, anthropometry, and hormone profiles when compared with age-matched sedentary counterparts (S [n = 28]). The MA group was predominantly aerobically trained with some resistance exercise incorporated in their routine. The VO(2max), peak power output, and salivary testosterone was significantly higher (p < 0.05) in the MA group, while diastolic blood pressure, systolic blood pressure, and body fat percentage were lower (p < 0.05). Cortisol, fat free mass, (FFM) and total body mass were not significantly different between groups. Salivary testosterone correlated positively with VO(2max) (r(2) = .320), suggesting that increased aerobic capacity is linked with higher concentrations of testosterone. These results suggest that life-long exercise is associated with favorable body composition and attenuation of the age related decline in testosterone.