121 Telomere attrition is attenuated in ultra-marathon runners
- Denham, Joshua, Nankervis, Scott, Debiec, Radek, Harvey, Jack, Pascoe, Deborah, Marques, Francine, O’Brien, Brendan, Zukowska-Szczechowska, Ewa, Tomaszewski, Maciej, Charchar, Fadi
- Authors: Denham, Joshua , Nankervis, Scott , Debiec, Radek , Harvey, Jack , Pascoe, Deborah , Marques, Francine , O’Brien, Brendan , Zukowska-Szczechowska, Ewa , Tomaszewski, Maciej , Charchar, Fadi
- Date: 2012
- Type: Text , Journal article
- Relation: Journal of Hypertension Vol. 30, no. e-Supplement (September 2012), p. e37
- Full Text: false
- Reviewed:
- Description: Background: Leukocyte telomere length is a marker of biological ageing and its shortening is associated with cardiovascular disease. Engagement in regular moderate-intensity physical activity is a recognised method of cardiovascular disease prevention. However, it is not clear whether repeated exposure to ultra-strenuous physical exercise is beneficial long-term and whether it may attenuate biological ageing. Methods: We compared leukocyte telomere length in context of inflammation and endothelial dysfunction between 67 male ultra-marathon runners and 67 age-, sex- and BMI-matched apparently healthy controls. Genomic DNA was extracted from peripheral blood and leukocyte telomere length was measured by quantitative polymerase chain reaction assays. Adhesion molecules (sICAM-1, sE-selectin) and inflammatory markers (IL-6, C-reactive protein) concentrations were measured in 67 ultra-marathon runners by quantitative sandwich enzyme immunoassay technique, high-sensitive immunoassay and ultra-sensitive double antibody sandwich ELISA, respectively. Results: Adjusted (for age, BMI, blood pressure and lipids) leukocyte telomere length was approximately 13.8% greater in the ultra-marathon runners than in the controls (P<0.001). This translates into approximately 32.9 years difference in age-related telomere length attrition. There was a strong negative linear correlation between sICAM-1 and leukocyte telomere length in the ultra-marathon runners (r=-0.33; P=0.007) and this association retained its statistical significance after adjustment for age, BMI, blood pressure and lipids in multiple regression (P=0.026). Conclusion: Prolonged, intense physical exercise may attenuate cellular ageing possibly through a protective effect on endothelial function.
- Description: C1
Quantifying cricket fast-bowling skill
- Feros, Simon, Young, Warren, O’Brien, Brendan
- Authors: Feros, Simon , Young, Warren , O’Brien, Brendan
- Date: 2018
- Type: Text , Journal article , Review
- Relation: International Journal of Sports Physiology and Performance Vol. 13, no. 7 (2018), p. 830-838
- Full Text: false
- Reviewed:
- Description: Objectives: To evaluate the current evidence regarding the quantification of cricket fast-bowling skill. Methods: Studies that assessed fast-bowling skill (bowling speed and accuracy) were identified from searches in SPORTDiscus (EBSCO) in June 2017. The reference lists of identified papers were also examined for relevant investigations. Results: A total of 16 papers matched the inclusion criteria, and discrepancies in assessment procedures were evident. Differences in test environment, pitch, and cricket ball characteristics; the warm-up prior to test; test familiarization procedures; permitted run-up lengths; bowling spell length; delivery sequence; test instructions; collection of bowling speed data; and collection and reportage of bowling accuracy data were apparent throughout the literature. The reliability and sensitivity of fast-bowling skill measures have rarely been reported across the literature. Only 1 study has attempted to assess the construct validity of its skill measures. Conclusions: There are several discrepancies in how fast-bowling skill has been assessed and subsequently quantified in the literature to date. This is a problem, because comparisons between studies are often difficult. Therefore, a strong rationale exists for the creation of match-specific standardized fast-bowling assessments that offer greater ecological validity while maintaining acceptable reliability and sensitivity of the skill measures. If prospective research can act on the proposed recommendations from this review, then coaches will be able to make more informed decisions surrounding player selection, talent identification, return to skill following injury, and the efficacy of short- and long-term training interventions for fast bowlers.
Aortic augmentation index in endurance athletes : A role for cardiorespiratory fitness
- Denham, Joshua, Brown, Nicholas, Tomaszewski, Maciej, Williams, Bryan, O’Brien, Brendan, Charchar, Fadi
- Authors: Denham, Joshua , Brown, Nicholas , Tomaszewski, Maciej , Williams, Bryan , O’Brien, Brendan , Charchar, Fadi
- Date: 2016
- Type: Text , Journal article
- Relation: European Journal of Applied Physiology Vol. 116, no. 8 (2016), p. 1537-1544
- Relation: http://purl.org/au-research/grants/nhmrc/1009490
- Full Text: false
- Reviewed:
- Description: Purpose: Endurance exercise improves cardiovascular health and reduces mortality risk. Augmentation index (AIx) reflects adverse loading exerted on the heart and large arteries and predicts future cardiovascular disease. The purpose of this study was to establish whether endurance athletes possess lower AIx and aortic blood pressure compared to healthy controls, and to determine the association between AIx and cardiorespiratory fitness. Methods: Forty-six endurance athletes and 43 healthy controls underwent central BP and AIx measurements by non-invasive applanation tonometry before a maximal exercise test. Peak oxygen uptake (V˙ O 2 peak) was assessed by pulmonary analysis. Results: Relative to controls, athletes had significantly lower brachial diastolic blood pressure (BP, −4.8 mmHg, p < 0.01), central systolic BP (−3.5 mmHg, p = 0.07), and AIx at a heart rate of 75 beats min−1 (AIx@75, −11.9 %, p < 0.001). No AIx@75 differences were observed between athletes and controls when adjusted for age and V˙ O 2 peak [athletes vs controls mean (%) ± SE: −6.9 ± 2.2 vs −5.7 ± 2.3, p = 0.76]. Relative to men with low V˙ O 2 peak, those with moderate and high V˙ O 2 peak had lower age-adjusted AIx@75 (p < 0.001). In women, those with high V˙ O 2 peak had lower AIx@75 than those with low and moderate V˙ O 2 peak (p < 0.01). Conclusions: The lower AIx@75 in endurance athletes is partly mediated by V˙ O 2 peak. While an inverse relationship between AIx@75 and V˙ O 2 peak was found in men, women with the highest V˙ O 2 peak possessed lowest AIx@75 compared to females with moderate or poor cardiorespiratory fitness. We recommend aerobic training aimed at achieving a minimum V˙ O 2 peak of 45 ml kg−1 min−1 to decrease the risk of future cardiovascular events and all-cause mortality.
- Description: Purpose: Endurance exercise improves cardiovascular health and reduces mortality risk. Augmentation index (AIx) reflects adverse loading exerted on the heart and large arteries and predicts future cardiovascular disease. The purpose of this study was to establish whether endurance athletes possess lower AIx and aortic blood pressure compared to healthy controls, and to determine the association between AIx and cardiorespiratory fitness. Methods: Forty-six endurance athletes and 43 healthy controls underwent central BP and AIx measurements by non-invasive applanation tonometry before a maximal exercise test. Peak oxygen uptake (V˙ O 2 peak) was assessed by pulmonary analysis. Results: Relative to controls, athletes had significantly lower brachial diastolic blood pressure (BP, −4.8 mmHg, p < 0.01), central systolic BP (−3.5 mmHg, p = 0.07), and AIx at a heart rate of 75 beats min−1 (AIx@75, −11.9 %, p < 0.001). No AIx@75 differences were observed between athletes and controls when adjusted for age and V˙ O 2 peak [athletes vs controls mean (%) ± SE: −6.9 ± 2.2 vs −5.7 ± 2.3, p = 0.76]. Relative to men with low V˙ O 2 peak, those with moderate and high V˙ O 2 peak had lower age-adjusted AIx@75 (p < 0.001). In women, those with high V˙ O 2 peak had lower AIx@75 than those with low and moderate V˙ O 2 peak (p < 0.01). Conclusions: The lower AIx@75 in endurance athletes is partly mediated by V˙ O 2 peak. While an inverse relationship between AIx@75 and V˙ O 2 peak was found in men, women with the highest V˙ O 2 peak possessed lowest AIx@75 compared to females with moderate or poor cardiorespiratory fitness. We recommend aerobic training aimed at achieving a minimum V˙ O 2 peak of 45 ml kg−1 min−1 to decrease the risk of future cardiovascular events and all-cause mortality. © 2016, Springer-Verlag Berlin Heidelberg.
The reliability and sensitivity of performance measures in a novel pace-bowling test
- Feros, Simon, Young, Warren, O’Brien, Brendan
- Authors: Feros, Simon , Young, Warren , O’Brien, Brendan
- Date: 2018
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 13, no. 2 (2018), p. 151-155
- Full Text:
- Reviewed:
- Description: Objectives: To evaluate the reliability and sensitivity of performance measures in a novel pace-bowling test. Methods: Thirteen male amateur-club fast bowlers completed a novel pace-bowling test on 2 separate occasions, 4–7 d apart. Participants delivered 48 balls (8 overs) at 5 targets on a suspended sheet situated behind a live batter, who stood in a right-handed and left-handed stance for an equal number of deliveries. Delivery instruction was frequently changed, with all deliveries executed in a preplanned sequence. Data on ball-release speed were captured by radar gun. A high-speed camera captured the moment of ball impact on the target sheet for assessment of radial error and bivariate variable error. Delivery rating of perceived exertion (0–100%) was collected as a measure of intensity. Results: Intraclass correlation coefficients and coefficients of variation revealed excellent reliability for peak and mean ball-release speed, acceptable reliability for delivery rating of perceived exertion, and poor reliability for mean radial error, bivariate variable error, and variability of ball-release speed. The smallest worthwhile change indicated high sensitivity with peak and mean ball-release speed and lower sensitivity with mean radial error and bivariate variable error. Conclusions: The novel pace-bowling test incorporates improvements in ecological validity compared with its predecessors and can be used to provide a more comprehensive evaluation of pace-bowling performance. Data on the smallest worthwhile change can improve interpretation of pace-bowling research findings and may therefore influence recommendations for applied practice. © 2018 Human Kinetics, Inc.
- Authors: Feros, Simon , Young, Warren , O’Brien, Brendan
- Date: 2018
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 13, no. 2 (2018), p. 151-155
- Full Text:
- Reviewed:
- Description: Objectives: To evaluate the reliability and sensitivity of performance measures in a novel pace-bowling test. Methods: Thirteen male amateur-club fast bowlers completed a novel pace-bowling test on 2 separate occasions, 4–7 d apart. Participants delivered 48 balls (8 overs) at 5 targets on a suspended sheet situated behind a live batter, who stood in a right-handed and left-handed stance for an equal number of deliveries. Delivery instruction was frequently changed, with all deliveries executed in a preplanned sequence. Data on ball-release speed were captured by radar gun. A high-speed camera captured the moment of ball impact on the target sheet for assessment of radial error and bivariate variable error. Delivery rating of perceived exertion (0–100%) was collected as a measure of intensity. Results: Intraclass correlation coefficients and coefficients of variation revealed excellent reliability for peak and mean ball-release speed, acceptable reliability for delivery rating of perceived exertion, and poor reliability for mean radial error, bivariate variable error, and variability of ball-release speed. The smallest worthwhile change indicated high sensitivity with peak and mean ball-release speed and lower sensitivity with mean radial error and bivariate variable error. Conclusions: The novel pace-bowling test incorporates improvements in ecological validity compared with its predecessors and can be used to provide a more comprehensive evaluation of pace-bowling performance. Data on the smallest worthwhile change can improve interpretation of pace-bowling research findings and may therefore influence recommendations for applied practice. © 2018 Human Kinetics, Inc.
Success in national level junior tennis : Tactical perspectives
- Klaus, Anne, Bradshaw, Ryan, Young, Warren, O’Brien, Brendan, Zois, James
- Authors: Klaus, Anne , Bradshaw, Ryan , Young, Warren , O’Brien, Brendan , Zois, James
- Date: 2017
- Type: Text , Journal article
- Relation: International Journal of Sports Science and Coaching Vol. 12, no. 5 (2017), p. 618-622
- Full Text:
- Reviewed:
- Description: Purpose: Point duration in competitive tennis is becoming shorter, highlighting a greater emphasis on performance of the first strokes of each point, in particular, the performance of the server. Methods: Descriptive measures of the video-based analysis included stroke type, point outcome and stroke position of the first two strokes of the server (service and first shot) during 10 randomly selected sets of competition on hard court. All participants (male; n=8) were of the age group 14 years and below and competed in national level events. Results: The performance of the first serve is characterized by an “in-percentage” of 54.6% and an improved chance of winning the point (for the server) following a first serve (55.9%; P<0.001) compared to a second serve (42.9%). The majority of stroke positions for first-shot winners were located in the central zone of the court (52.1%; P<0.01). In comparison to the error rate of all examined strokes, we observed an increased error rate of the first shot (16.5% vs. 22.4%; P<0.01). Conclusion: Contrasting to professionals, juniors produce more first-serve errors and win fewer points directly via the serve. Success in junior tennis relies in minimizing errors within short rallies specifically on the first shot of the server. Coaches of national level junior tennis players should focus on strategies to optimize court position following the serve and service percentage to increase competitive success rate. To achieve this, the server should utilize the serve as a “set-up” tool, dictating the direction of the returner’s return of serve within the central zones of the court. © The Author(s) 2017.
- Authors: Klaus, Anne , Bradshaw, Ryan , Young, Warren , O’Brien, Brendan , Zois, James
- Date: 2017
- Type: Text , Journal article
- Relation: International Journal of Sports Science and Coaching Vol. 12, no. 5 (2017), p. 618-622
- Full Text:
- Reviewed:
- Description: Purpose: Point duration in competitive tennis is becoming shorter, highlighting a greater emphasis on performance of the first strokes of each point, in particular, the performance of the server. Methods: Descriptive measures of the video-based analysis included stroke type, point outcome and stroke position of the first two strokes of the server (service and first shot) during 10 randomly selected sets of competition on hard court. All participants (male; n=8) were of the age group 14 years and below and competed in national level events. Results: The performance of the first serve is characterized by an “in-percentage” of 54.6% and an improved chance of winning the point (for the server) following a first serve (55.9%; P<0.001) compared to a second serve (42.9%). The majority of stroke positions for first-shot winners were located in the central zone of the court (52.1%; P<0.01). In comparison to the error rate of all examined strokes, we observed an increased error rate of the first shot (16.5% vs. 22.4%; P<0.01). Conclusion: Contrasting to professionals, juniors produce more first-serve errors and win fewer points directly via the serve. Success in junior tennis relies in minimizing errors within short rallies specifically on the first shot of the server. Coaches of national level junior tennis players should focus on strategies to optimize court position following the serve and service percentage to increase competitive success rate. To achieve this, the server should utilize the serve as a “set-up” tool, dictating the direction of the returner’s return of serve within the central zones of the court. © The Author(s) 2017.
Telomeres, aging and exercise : Guilty by association?
- Chilton, Warrick, O’Brien, Brendan, Charchar, Fadi
- Authors: Chilton, Warrick , O’Brien, Brendan , Charchar, Fadi
- Date: 2017
- Type: Text , Journal article , Review
- Relation: International Journal of Molecular Sciences Vol. 18, no. 12 (2017), p. 1-32
- Full Text:
- Reviewed:
- Description: Telomeres are repetitive tandem DNA sequences that cap chromosomal ends protecting genomic DNA from enzymatic degradation. Telomeres progressively shorten with cellular replication and are therefore assumed to correlate with biological and chronological age. An expanding body of evidence suggests (i) a predictable inverse association between telomere length, aging and age-related diseases and (ii) a positive association between physical activity and telomere length. Both hypotheses have garnered tremendous research attention and broad consensus; however, the evidence for each proposition is inconsistent and equivocal at best. Telomere length does not meet the basic criteria for an aging biomarker and at least 50% of key studies fail to find associations with physical activity. In this review, we address the evidence in support and refutation of the putative associations between telomere length, aging and physical activity. We finish with a brief review of plausible mechanisms and potential future research directions. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.
- Authors: Chilton, Warrick , O’Brien, Brendan , Charchar, Fadi
- Date: 2017
- Type: Text , Journal article , Review
- Relation: International Journal of Molecular Sciences Vol. 18, no. 12 (2017), p. 1-32
- Full Text:
- Reviewed:
- Description: Telomeres are repetitive tandem DNA sequences that cap chromosomal ends protecting genomic DNA from enzymatic degradation. Telomeres progressively shorten with cellular replication and are therefore assumed to correlate with biological and chronological age. An expanding body of evidence suggests (i) a predictable inverse association between telomere length, aging and age-related diseases and (ii) a positive association between physical activity and telomere length. Both hypotheses have garnered tremendous research attention and broad consensus; however, the evidence for each proposition is inconsistent and equivocal at best. Telomere length does not meet the basic criteria for an aging biomarker and at least 50% of key studies fail to find associations with physical activity. In this review, we address the evidence in support and refutation of the putative associations between telomere length, aging and physical activity. We finish with a brief review of plausible mechanisms and potential future research directions. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.
Plasma lipocalin-2/NGAL is stable over 12 weeks and is not modulated by exercise or dieting
- Nakai, Michael, Prestes, Priscilla, O’Brien, Brendan, Charchar, Fadi, Marques, Francine
- Authors: Nakai, Michael , Prestes, Priscilla , O’Brien, Brendan , Charchar, Fadi , Marques, Francine
- Date: 2021
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 11, no. 1 (2021), p.
- Full Text:
- Reviewed:
- Description: Amongst other immune cells, neutrophils play a key role in systemic inflammation leading to cardiovascular disease and can release inflammatory factors, including lipocalin-2 (LCN2). LCN2 drives cardiac hypertrophy and plays a role in maladaptive remodelling of the heart and has been associated with renal injury. While lifestyle factors such as diet and exercise are known to attenuate low-grade inflammation, their ability to modulate plasma LCN2 levels is unknown. Forty-eight endurance athletes and 52 controls (18–55 years) underwent measurement for various cardiovascular health indicators, along with plasma LCN2 concentration. No significant difference in LCN2 concentration was seen between the two groups. LCN2 was a very weak predictor or absent from models describing blood pressures or predicting athlete status. In another cohort, 57 non-diabetic overweight or obese men and post-menopausal women who fulfilled Adult Treatment Panel III metabolic syndrome criteria were randomly allocated into either a control, modified Dietary Approaches to Stop Hypertension (DASH) diet, or DASH and exercise group. Pre- and post-intervention demographic, cardiovascular health indicators, and plasma LCN2 expression were measured in each individual. While BMI fell in intervention groups, LCN2 levels remained unchanged within and between all groups, as illustrated by strong correlations between LCN2 concentrations pre- and 12 weeks post-intervention (r = 0.743, P < 0.0001). This suggests that circulating LCN2 expression are stable over a period of at least 12 weeks and is not modifiable by diet and exercise. © 2021, The Author(s). *Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Priscilla Prestes, Brendan O'Brien, Fadi Charchar and Francine Marques” is provided in this record** .
- Authors: Nakai, Michael , Prestes, Priscilla , O’Brien, Brendan , Charchar, Fadi , Marques, Francine
- Date: 2021
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 11, no. 1 (2021), p.
- Full Text:
- Reviewed:
- Description: Amongst other immune cells, neutrophils play a key role in systemic inflammation leading to cardiovascular disease and can release inflammatory factors, including lipocalin-2 (LCN2). LCN2 drives cardiac hypertrophy and plays a role in maladaptive remodelling of the heart and has been associated with renal injury. While lifestyle factors such as diet and exercise are known to attenuate low-grade inflammation, their ability to modulate plasma LCN2 levels is unknown. Forty-eight endurance athletes and 52 controls (18–55 years) underwent measurement for various cardiovascular health indicators, along with plasma LCN2 concentration. No significant difference in LCN2 concentration was seen between the two groups. LCN2 was a very weak predictor or absent from models describing blood pressures or predicting athlete status. In another cohort, 57 non-diabetic overweight or obese men and post-menopausal women who fulfilled Adult Treatment Panel III metabolic syndrome criteria were randomly allocated into either a control, modified Dietary Approaches to Stop Hypertension (DASH) diet, or DASH and exercise group. Pre- and post-intervention demographic, cardiovascular health indicators, and plasma LCN2 expression were measured in each individual. While BMI fell in intervention groups, LCN2 levels remained unchanged within and between all groups, as illustrated by strong correlations between LCN2 concentrations pre- and 12 weeks post-intervention (r = 0.743, P < 0.0001). This suggests that circulating LCN2 expression are stable over a period of at least 12 weeks and is not modifiable by diet and exercise. © 2021, The Author(s). *Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Priscilla Prestes, Brendan O'Brien, Fadi Charchar and Francine Marques” is provided in this record** .
- «
- ‹
- 1
- ›
- »