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
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- 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** .
Coconut water : a sports drink alternative?
- O’Brien, Brendan, Bell, Leo, Hennessy, Declan, Denham, Joshua, Paton, Carl
- Authors: O’Brien, Brendan , Bell, Leo , Hennessy, Declan , Denham, Joshua , Paton, Carl
- Date: 2023
- Type: Text , Journal article
- Relation: Sports Vol. 11, no. 9 (2023), p.
- Full Text:
- Reviewed:
- Description: Coconut water is used as an alternative to conventional sports drinks for hydration during endurance cycling; however, evidence supporting its use is limited. This study determined if drinking coconut water compared to a sports drink altered cycling performance and physiology. In a randomized crossover trial, 19 experienced male (n = 15) and female (n = 4) cyclists (age 30 ± 9 years, body mass 79 ± 11 kg, (Formula presented.) O2 peak 55 ± 8 mL·kg
- Authors: O’Brien, Brendan , Bell, Leo , Hennessy, Declan , Denham, Joshua , Paton, Carl
- Date: 2023
- Type: Text , Journal article
- Relation: Sports Vol. 11, no. 9 (2023), p.
- Full Text:
- Reviewed:
- Description: Coconut water is used as an alternative to conventional sports drinks for hydration during endurance cycling; however, evidence supporting its use is limited. This study determined if drinking coconut water compared to a sports drink altered cycling performance and physiology. In a randomized crossover trial, 19 experienced male (n = 15) and female (n = 4) cyclists (age 30 ± 9 years, body mass 79 ± 11 kg, (Formula presented.) O2 peak 55 ± 8 mL·kg
Stubborn exercise responders–where to next?
- Bell, Leo, Gabbett, Tim, Davis, Gregory, Wallen, Matthew, O’Brien, Brendan
- Authors: Bell, Leo , Gabbett, Tim , Davis, Gregory , Wallen, Matthew , O’Brien, Brendan
- Date: 2022
- Type: Text , Journal article , Review
- Relation: Sports Vol. 10, no. 6 (2022), p.
- Full Text:
- Reviewed:
- Description: There is a wide variance in the magnitude of physiological adaptations after resistance or endurance training. The incidence of “non” or “poor” responders to training has been reported to represent as high as 40% of the project’s sample. However, the incidence of poor responders to training can be ameliorated with manipulation of either the training frequency, intensity, type and duration. Additionally, global non‐response to cardio‐respiratory fitness training is eliminated when evaluating several health measures beyond just the target variables as at least one or more measure improves. More research is required to determine if altering resistance training variables results in a more favourable response in individuals with an initial poor response to resistance training. Moreover, we recommend abandoning the term “poor” responders, as ultimately the magnitude of change in cardiorespiratory fitness in response to endurance training is similar in “poor” and “high” responders if the training frequency is subsequently increased. Therefore, we propose “stubborn” responders as a more appropriate term. Future research should focus on developing viable physiological and lifestyle screening tests that identify likely stubborn responders to conventional exercise training guidelines before the individual engages with training. Exerkines, DNA damage, metabolomic responses in blood, saliva and breath, gene sequence, gene expression and epigenetics are candidate biomarkers that warrant investigation into their relationship with traina-bility. Crucially, viable biomarker screening tests should show good construct validity to distinguish between different exercise loads, and possess excellent sensitivity and reliability. Furthermore “red flag” tests of likely poor responders to training should be practical to assess in clinical settings and be affordable and non‐invasive. Early identification of stubborn responders would enable op-timization of training programs from the onset of training to maintain exercise motivation and optimize the impact on training adaptations and health. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
- Authors: Bell, Leo , Gabbett, Tim , Davis, Gregory , Wallen, Matthew , O’Brien, Brendan
- Date: 2022
- Type: Text , Journal article , Review
- Relation: Sports Vol. 10, no. 6 (2022), p.
- Full Text:
- Reviewed:
- Description: There is a wide variance in the magnitude of physiological adaptations after resistance or endurance training. The incidence of “non” or “poor” responders to training has been reported to represent as high as 40% of the project’s sample. However, the incidence of poor responders to training can be ameliorated with manipulation of either the training frequency, intensity, type and duration. Additionally, global non‐response to cardio‐respiratory fitness training is eliminated when evaluating several health measures beyond just the target variables as at least one or more measure improves. More research is required to determine if altering resistance training variables results in a more favourable response in individuals with an initial poor response to resistance training. Moreover, we recommend abandoning the term “poor” responders, as ultimately the magnitude of change in cardiorespiratory fitness in response to endurance training is similar in “poor” and “high” responders if the training frequency is subsequently increased. Therefore, we propose “stubborn” responders as a more appropriate term. Future research should focus on developing viable physiological and lifestyle screening tests that identify likely stubborn responders to conventional exercise training guidelines before the individual engages with training. Exerkines, DNA damage, metabolomic responses in blood, saliva and breath, gene sequence, gene expression and epigenetics are candidate biomarkers that warrant investigation into their relationship with traina-bility. Crucially, viable biomarker screening tests should show good construct validity to distinguish between different exercise loads, and possess excellent sensitivity and reliability. Furthermore “red flag” tests of likely poor responders to training should be practical to assess in clinical settings and be affordable and non‐invasive. Early identification of stubborn responders would enable op-timization of training programs from the onset of training to maintain exercise motivation and optimize the impact on training adaptations and health. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
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