Genome-wide sperm DNA methylation changes after 3 months of exercise training in humans
- Authors: Denham, Joshua , O'Brien, Brendan , Harvey, Jack , Charchar, Fadi
- Date: 2015
- Type: Text , Journal article
- Relation: Epigenomics Vol. 7, no. 5 (2015), p. 717-731
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- Description: Aim: DNA methylation programs gene expression and is involved in numerous biological processes. Accumulating evidence supports transgenerational inheritance of DNA methylation changes in mammals via germ cells. Our aim was to determine the effect of exercise on sperm DNA methylation. Materials & methods: Twenty-four men were recruited and assigned to an exercise intervention or control group. Clinical parameters were measured and sperm samples were donated by subjects before and after the 3-month time-period. Mature sperm global and genome-wide DNA methylation was assessed using an ELISA assay and the 450K BeadChip (Illumina). Results: Global and genome-wide sperm DNA methylation was altered after 3 months of exercise training. DNA methylation changes occurred in genes related to numerous diseases such as schizophrenia and Parkinson's disease. Conclusions: Our study provides the first evidence showing exercise training reprograms the sperm methylome. Whether these DNA methylation changes are inherited to future generations warrants attention.
Assessment of decision-making performance and in-game physical exertion of Australian football umpires
- Authors: Larkin, Paul , O'Brien, Brendan , Mesagno, Christopher , Berry, Jason , Harvey, Jack , Spittle, Michael
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Sports Sciences Vol. 32, no. 15 (2014), p. 1446-1453
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- Description: The aim of this study is to investigate the effects of in-game physical exertion on decision-making performance of Australian football umpires. Fifteen Australian football umpires (Mage = 36, s = 13.5 years; Mgames umpired = 235.2, s = 151.3) volunteered to participate in the study. During five competitive Australian football pre-season games, measures of in-game physical exertion (blood lactate levels, global positioning system [GPS]) and decision-making performance (video-based test) were obtained. There were no significant correlations between physical exertion in a particular quarter and decision-making performance in either the same quarter or any other quarter. Video-based decision-making performance was effected by time in game χ2(3) = 24.24, P = 0.001, with Quarter 4 performance significantly better than both Quarter 2 and Quarter 3. In-game physical exertion (blood lactate) significantly decreased over the course of the game χ2(3) = 11.58, P = 0.009. Results indicate no definable link between in-game physical exertion and decision-making performance. It is, however, presumed that decision-making performance may be affected by the time or context of the game. Future research is warranted to explore the relationship between physical exertion and decision-making performance to potentially inform Australian football umpire training programmes that replicate in-game physical and decision-making demands.
Longer leukocyte telomeres are associated with ultra-endurance exercise independent of cardiovascular risk factors
- Authors: Denham, Joshua , Nelson, Christopher , O'Brien, Brendan , Nankervis, Scott , Denniff, Matthew , Harvey, Jack , Marques, Francine , Codd, Veryan , Zukowska-Szczechowska, Ewa , Samani, Nilesh , Tomaszewski, Maciej , Charchar, Fadi
- Date: 2013
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 8, no. 7 (2013), p.
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- Description: Telomere length is recognized as a marker of biological age, and shorter mean leukocyte telomere length is associated with increased risk of cardiovascular disease. It is unclear whether repeated exposure to ultra-endurance aerobic exercise is beneficial or detrimental in the long-term and whether it attenuates biological aging. We quantified 67 ultra-marathon runners' and 56 apparently healthy males' leukocyte telomere length (T/S ratio) using real-time quantitative PCR. The ultra-marathon runners had 11% longer telomeres (T/S ratio) than controls (ultra-marathon runners: T/S ratio = 3.5±0.68, controls: T/S ratio = 3.1±0.41;
- Description: 2003011219
Acute effect of exercise on kicking accuracy in elite Australian football players
- Authors: Young, Warren , Gulli, Rachael , Rath, David , Russell, Andrew , O'Brien, Brendan , Harvey, Jack
- Date: 2010
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 13, no. 1 (2010), p. 85-89
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- Description: Kicking accuracy (KA) is an important skill in Australian football but the potential influence of exercise on this skill has not been previously investigated. The purpose of this study was to determine if a 2× 2 min time trial running protocol influenced short KA in elite Australian football. Another aim was to identify if endurance, playing experience and position were related to any exercise-induced KA changes. Twenty-seven professional footballers performed a KA test by kicking at a bullseye on a target projected onto a screen. The mean error from the centre of the target was the KA score. The players were assessed on the KA test, and then performed a 2× 2 min time trial with a 3-min recovery between runs. The total distance covered was used as a measure of endurance fitness, and the test also served as an exercise bout designed to impose some physiological stress. Immediately following this test, the players walked into the laboratory and performed the KA test again. A paired t-test revealed that the whole group achieved a non-significant 2.7% improvement in KA. Players were divided into two distinct groups based on endurance (2× 2 min results), playing experience and position (midfielders and forwards/backs). Analysis of covariance showed that after the exercise bout, the fitter group had significantly better KA (p = 0.010) than the less fit group, and the more experienced players were 16% more accurate than the less experienced group (p = 0.055). The midfielders were 8.2% better than the forwards/backs in KA (p = 0.32). It was suggested that greater endurance and playing experience may facilitate KA under moderate physiological stress. © 2008 Sports Medicine Australia.
- Description: 2003008125
Treadmill velocity best predicts 5000-m run performance
- Authors: Stratton, E. , O'Brien, Brendan , Harvey, Jack , Blitvich, Jennifer , McNicol, Ashleigh , Janissen, D. , Paton, Carl , Knez, Wade
- Date: 2009
- Type: Text , Journal article
- Relation: International Journal of Sports Medicine Vol. 30, no. 1 (2009), p. 40-45
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- Description: In this study, we aimed to investigate physiological determinants of endurance performance that best predict 5000-m average run velocity before and after endurance training. Thirty-nine previously untrained participants completed a 5000-m run; a constant velocity test (measuring running economy); and an incremental treadmill test to determine maximal oxygen uptake, final treadmill velocity, and velocity and oxygen uptake at lactate threshold, before and after six weeks of endurance training. Maximal oxygen uptake, final treadmill velocity, and velocity and oxygen uptake at threshold all increased significantly after training (p < 0.05). Average velocity for 5000m increased significantly (p < 0.05). Running economy was not significantly altered. Correlation analysis revealed final treadmill velocity was most strongly related to 5000-m performance, in both untrained and trained states (r = 0.89, 0.83). Lactate threshold velocity (r = 0.73, 0.76), maximal oxygen uptake (r = 0.55, 0.51) and oxygen uptake at threshold (r = 0.45, 0.45) also showed significant correlations. In contrast, running economy was not significantly related to performance. These results demonstrate that final treadmill velocity in an V̇O2max test is the single best predictor of 5000-m performance in untrained and trained states. Furthermore, stepwise regression analysis showed that only velocity at lactate threshold significantly improved the accuracy of prediction provided by final treadmill velocity alone. © Georg Thieme Verlag KG Stuttgart.
- Description: 2003008110
The effects of interval-exercise duration and intensity on oxygen consumption during treadmill running
- Authors: O'Brien, Brendan , Wibskov, Jim , Knez, Wade , Paton, Carl , Harvey, Jack
- Date: 2008
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 11, no. 3 (2008), p. 287-290
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- Description: The magnitude of improvement in peak oxygen uptake (over(V, ̇)
- Description: C1