Common high-speed running thresholds likely do not correspond to high-speed running in field sports
- Authors: Freeman, Brock , Talpey, Scott , James, Lachlan , Opar, David , Young, Warren
- Date: 2023
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 37, no. 7 (2023), p. 1411-1418
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- Description: The purpose of this study was to clarify what percentage of maximum speed is associated with various running gaits. Fifteen amateur field sport athletes (age = 23 ± 3.6 years) participated in a series of 55-meter running trials. The speed of each trial was determined by instructions relating to 5 previously identified gait patterns (jog, run, stride, near maximum sprint, and sprint). Each trial was filmed in slow motion (240 fps), whereas running speed was obtained using Global Positioning Systems. Contact time, stride angle, and midstance free-leg knee angle were determined from video footage. Running gaits corresponded with the following running speeds, jogging = 4.51 m·s-1, 56%Vmax, running = 5.41 m·s-1, 66%Vmax,striding = 6.37 m·s-1, 78%Vmax, near maximum sprinting = 7.08 m·s-1, 87%Vmax, and sprinting = 8.15 m·s-1, 100%Vmax. Significant (p < 0.05) increases in stride angle were observed as running speed increased. Significant (p < 0.05) decreases were observed in contact time and midstance free-leg knee angle as running speed increased. These findings suggest currently used thresholds for high-speed running (HSR) and sprinting most likely correspond with jogging and striding, which likely underestimates the true HSR demands. Therefore, a higher relative speed could be used to describe HSR and sprinting more accurately in field sports. © 2023 NSCA National Strength and Conditioning Association. All rights reserved.
From the field- program outline : development of a speed program for elite junior Australian Rules Football Players
- Authors: Young, Warren , Carr, Sam , Freeman, Brock
- Date: 2021
- Type: Text , Journal article
- Relation: The Journal Of Australian Strength And Conditioning, JASC Vol. 29, no. 4 (2021), p.
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- Description: A speed program was developed for two male sixteen-year-old Australian Rules footballers who play state level competition. The program targeted acceleration, repeat sprint ability (RSA), and agility, and was performed two days per week on a natural grass oval. Examples of activities are provided for each speed quality. A key activity for acceleration was resisted sprinting involving towing a sled, which encouraged the desired body positions and technique. Repeat sprint ability was developed by prescribing activities containing short sprints with minimal recovery periods. Agility techniques were initially introduced, and then training activities included evasive changes of direction in an attacking role, and also defensive manoeuvres in one-on-one scenarios. A central principle in the creation of training activities was to contextualise them to Australian Rules football, with the intention of maximising transfer to on-field performance. This involved stressing maximum efforts with sound sprint technique under various imposed perturbations, such as the execution of football skills, pressure from an opponent, and fatigue.
Sprinting and hamstring strain injury : beliefs and practices of professional physical performance coaches in Australian football
- Authors: Freeman, Brock , Talpey, Scott , James, Lachlan , Young, Warren
- Date: 2021
- Type: Text , Journal article
- Relation: Physical Therapy in Sport Vol. 48, no. (2021), p. 12-19
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- Description: Objectives: The purpose of this study was to establish beliefs and practices of physical performance coaches regarding sprinting and Hamstring Strain Injury (HSI) in Australian Rules football. Designs: Delphi-validated questionnaire. Setting: Online. Participants: Eighteen high-performance managers of the Australian Football League. Main outcome measures: Descriptive statistics were collected to establish experience; central themes were established for the analyses of the beliefs and practices. Results: Nine (50%) physical performance coaches responded to an invitation to complete the questionnaire. Participants held an undergraduate degree and had 9.2 ± 4.3 years of experience. Accelerations (n = 9), maximum speed sprints (n = 9) and running with hip flexion (n = 7) were the most common activities associated with HSI. Coaches believed sprinting, eccentric strength training and proper periodisation were effective strategies to reduce HSI risk. There's a disparity between beliefs and practices when using GPS to monitor sprinting, however, all coaches reported regular exposure to sprint training across both pre and in-season. Overstriding (n = 9) and pelvic instability (n = 6) were identified as key flaws in running mechanics. Conclusions: This information can be used to improve training strategies, whilst these findings indicate further investigations into sprint training and running mechanics for HSI risk reduction. © 2020 Elsevier Ltd
The effects of sprint training and the Nordic hamstring exercise on eccentric hamstring strength and sprint performance in adolescent athletes
- Authors: Freeman, Brock , Young, Warren , Talpey, Scott , Smyth, Andrew , Pane, Calvin , Carlon, Todd
- Date: 2019
- Type: Text , Journal article
- Relation: Journal of Sports Medicine and Physical Fitness Vol. 59, no. 7 (2019), p. 1119-1125
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- Description: BACKGROUND. Hamstring strain injuries (HSI) are among the most common injuries in field-based team sports with a high-speed running component. The implementation of the Nordic hamstring exercise (NHE) is a well-documented method of improving eccentric hamstring strength to mitigate the risk of HSI occurrence. Sprint training is specific to the injury mechanism and is thought to activate the hamstrings through maximal eccentric contractions. The purpose of this study was to compare the effects of sprint training and the NHE on eccentric hamstring strength and sprint performance. METHODS. Twenty-eight participants (mean +/- SD age=16.21 +/- 1.34 years; height=1.75m +/- 0.10m; body mass=68.5kg +/- 12.1kg) completed an eccentric hamstring strength assessment and 40m sprint to assess acceleration and maximum speed. Participants were randomly allocated to either a NHE training or sprint training group. Two sessions per week for four-weeks of training was performed with baseline testing procedures repeated in the week following the intervention. Perceptions of soreness were recorded following the warm-up in each training session. RESULTS. Both the NHE (effect size=0.39, P<0.05) and sprint training (effect size=0.29, P<0.05) groups displayed significant gains in eccentric hamstring strength. The NHE group reported trivial improvements in sprint performance, whilst the sprint training group experienced a moderate improvement, specifically in maximum speed (ES=0.83 Moderate). Sprint training also produced greater perceptions of soreness than the NHE following a four-week training intervention, specifically before the start of the last session (P<0.05). CONCLUSIONS. These findings indicate that sprint training had a beneficial effect for both eccentric hamstring strength and sprint performance, whilst also producing greater soreness than the NHE following the final training session. It was concluded that a four-week block of maximum speed training may have both an injury prevention and performance enhancement benefit.