| 1. |
- Cook, C. J., et al.
(författare)
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Morning based strength training improves afternoon physical performance in rugby union players
- 2014
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Ingår i: Journal of Science and Medicine in Sport. - : Elsevier BV. - 1878-1861 .- 1440-2440. ; 17:3, s. 317-321
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesTo determine if a morning training session could alter afternoon physical performance. Moreover, as testosterone (T) and cortisol (C) concentrations are significant predictors of physical performance, and both show circadian declines across the day, we examined the effects of morning training on diurnal T and C responses. DesignEighteen semi-professional rugby union players completed this randomised and counter-balanced study. MethodsFollowing morning saliva collection (0900. h), players completed a control (rested), Sprint (5 × 40 m) or Weights (3 repetition-maximum [RM] bench press and squat) trial. In the afternoon (15:00. h) of each trial, a further saliva sample was collected before players completed a performance test (3RM back squat and bench press, 40. m sprint, countermovement jump [CMJ]). ResultsSalivary T concentrations declined from am to pm under Control and Sprint, but not under Weights. Delta T, from am to pm, was greater under Control (-10.9±2.4pgml-1) compared to Sprints (-6.2±7.1pgml-1) and Weights (-1.2±5.5pgml-1) (p≤0.001). Delta C, from am to pm, was greater under Control compared to both Sprint and Weights (p<0.05). Players elicited better CMJ peak power, 40-m time, 3RM bench and squat performance under Weights compared with Control and Sprint (p<0.05). Faster 40-m times were seen under Sprint, when compared to Control (p<0.05). ConclusionsPerforming morning strength training is associated with improved physical performance in the afternoon. Additionally, the circadian decline in T concentrations appeared offset by morning training. However, it is unclear if T concentrations are, in part, causal of these improved responses or simply a reflective marker. © 2013 Sports Medicine Australia.
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| 2. |
- West, Daniel J., et al.
(författare)
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THE INFLUENCE OF THE TIME OF DAY ON CORE TEMPERATURE AND LOWER BODY POWER OUTPUT IN ELITE RUGBY UNION SEVENS PLAYERS
- 2014
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Ingår i: JOURNAL OF STRENGTH AND CONDITIONING RESEARCH. - 1533-4287. ; 28:6, s. 1524-1528
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Tidskriftsartikel (refereegranskat)abstract
- Core temperature typically displays a low circadian in the morning before peaking later in the day, and these changes occur within small physiological ranges. Body temperature plays an important role in physical performance, and some athletes may be required to train and compete in both the morning and evening. However, the influence of the circadian change in body temperature and its influence on physical performance in elite athletes are unclear. This study examined the effects of the time of day on core temperature and lower body power output in elite rugby union sevens players. Sixteen elite rugby union sevens players completed morning (in AM) countermovement jump and core temperature (T-core) measurement, which were then repeated later the same day (in PM). Countermovement jump was processed for peak power output (PPO). Data were analyzed using paired samples t-test and Pearson's product moment correlation and are presented in mean +/- SD. T-core significantly increased from AM to PM (AM, 36.92 +/- 0.23 vs. PM, 37.18 +/- 0.188 degrees C; P < 0.001) with PPO significantly increasing from AM to PM in all 16 players (AM, 5248 +/- 366 vs. PM, 5413 +/- 361 W; P < 0.001). The delta change in T-core (0.26 +/- 0.138 degrees C) and PPO (164 +/- 78 W) was significantly related (r = 0.781; P < 0.001). In conclusion, small circadian changes in core temperature can influence physical performance in elite athletes. Coaches should seek to use strategies, which may raise morning body temperature to offset the circadian low in the morning.
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| 3. |
- Cook, C. J., et al.
(författare)
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Improving strength and power in trained athletes with 3 weeks of occlusion training
- 2014
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Ingår i: International Journal of Sports Physiology and Performance. - 1555-0265 .- 1555-0273. ; 9:1, s. 166-172
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To examine the effects of moderate-load exercise with and without blood-flow restriction (BFR) on strength, power, and repeated-sprint ability, along with acute and chronic salivary hormonal parameters. Methods: Twenty male semiprofessional rugby union athletes were randomized to a lower-body BFR intervention (an occlusion cuff inflated to 180 mmHg worn intermittently on the proximal thighs) or a control intervention that trained without occlusion in a crossover design. Experimental sessions were performed 3 times a week for 3 wk with 5 sets of 5 repetitions of bench press, leg squat, and pull-ups performed at 70% of 1-repetition maximum. Results: Greater improvements were observed (occlusion training vs control) in bench press (5.4 ± 2.6 vs 3.3 ± 1.4 kg), squat (7.8 ± 2.1 vs 4.3 ± 1.4 kg), maximum sprint time (-0.03 ± 0.03 vs -0.01 ± 0.02 s), and leg power (168 ± 105 vs 68 ± 50 W). Greater exercise-induced salivary testosterone (ES 0.84-0.61) and cortisol responses (ES 0.65-0.20) were observed after the occlusion intervention sessions compared with the nonoccluded controls; however, the acute cortisol increases were attenuated across the training block. Conclusions: Occlusion training can potentially improve the rate of strength-training gains and fatigue resistance in trained athletes, possibly allowing greater gains from lower loading that could be of benefit during high training loads, in competitive seasons, or in a rehabilitative setting. The clear improvement in bench-press strength resulting from lower-body occlusion suggests a systemic effect of BFR training. © 2014 Human Kinetics, Inc.
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| 4. |
- Cook, Christian J., et al.
(författare)
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Individual perception of recovery is related to subsequent sprint performance
- 2013
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Ingår i: British Journal of Sports Medicine. - : BMJ. - 0306-3674 .- 1473-0480. ; 47:11, s. 705-709
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Tidskriftsartikel (refereegranskat)abstract
- Background Training recovery is vital for adaptation and performance, and to avoid cumulative fatigue and symptoms associated with overtraining. The use of cold-water immersion (CWI) as a recovery strategy is common; however, the physiological and biochemical rationale behind its use remains unclear. This study aimed to assess the relationship between body temperature responses to water immersion and individual perception of recovery, with subsequent exercise performance. Methods Twelve male rugby players participated in a 3-week cross-over trial where an intense 60 min conditioning session was followed immediately by 15 min of either 14 degrees C CWI, 30 degrees C warm-water immersion (WWI) or passive control (CON) recovery intervention. Postexercise body temperatures and subjective ratings of the recovery intervention were recorded and subsequently related to performance in a 5x40 m repeated sprint protocol undertaken 24 h later. Results CWI induced large reductions in core body temperature postimmersion (effect size (ES) range 1.05-3.21) and improved subsequent sprint performance compared to WWI (ES 1.04 +/- 0.84) and CON (ES 1.44 +/- 0.84). Both the degree of temperature decrease at 60 min postimmersion (r=0.6948; p=0.0121) and the subjective rating of the recovery intervention (r=0.5886; p=0.0441) were related to subsequent sprint performance. A very strong linear correlation was observed when these two factors were integrated (r=0.7743; p=0.0031). Conclusion A combination of physiological and psychological indices provides an improved indication of subsequent performance and suggests an important role of individual perception in enhancing training recovery.
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| 5. |
- Cook, C. J., et al.
(författare)
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Salivary testosterone is related to self-selected training load in elite female athletes
- 2013
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Ingår i: Physiology and Behavior. - : Elsevier BV. - 0031-9384 .- 1873-507X. ; 116-117, s. 8-12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Testosterone has been related to improved acute neuromuscular performance in athletic populations. It is our contention that testosterone may also contribute to improved volitional motivation and, when monitored longitudinally, may provide one proxy marker for readiness to perform. Methods: Twelve female netball players provided saliva samples prior to five standardized training sessions in which they completed a maximal-distance medicine ball throw, and then 3 sets of bench press and then back squat using a self-selected load perceived to equal a 3-repetition maximum load. Additional repetitions were encouraged when possible and total voluntary workload was calculated from the product of the load lifted and repetitions performed. Results: Relative salivary testosterone levels as a group were correlated with bench press (r = 0.8399; p = 0.0007) and squat (r = 0.6703; p = 0.0171) self-selected workload, as well as maximal medicine ball throw performance (r = 0.7062; p = 0.0103). Conclusions: Individual salivary testosterone, when viewed relatively over time, demonstrated strong relationships with self-selected workloads during an in-season training period in female netball players. As such, daily variations in testosterone may provide information regarding voluntary training motivation and readiness to perform in elite athletic populations. Psychological and behavioral aspects of testosterone may have the potential to enhance training adaptation by complementing the known anabolic and permissive properties of testosterone.
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| 6. |
- Cook, Christian J., et al.
(författare)
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THREE WEEKS OF ECCENTRIC TRAINING COMBINED WITH OVERSPEED EXERCISES ENHANCES POWER AND RUNNING SPEED PERFORMANCE GAINS IN TRAINED ATHLETES
- 2013
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Ingår i: Journal of Strength and Conditioning Research. - 1064-8011 .- 1533-4287. ; 27:5, s. 1280-1286
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Tidskriftsartikel (refereegranskat)abstract
- Eccentric and overspeed training modalities are effective in improving components of muscular power. Eccentric training induces specific training adaptations relating to muscular force, whereas overspeed stimuli target the velocity component of power expression. We aimed to compare the effects of traditional or eccentric training with volume-matched training that incorporated overspeed exercises. Twenty team-sport athletes performed 4 counterbalanced 3-week training blocks consecutively as part of a preseason training period: (1) traditional resistance training; (2) eccentric-only resistance training; (3) traditional resistance training with overspeed exercises; and (4) eccentric resistance training with overspeed exercises. The overspeed exercises performed were assisted countermovement jumps and downhill running. Improvements in bench press (15.0 +/- 5.1 kg; effect size [ES]: 1.52), squat (19.5 +/- 9.1 kg; ES: 1.12), and peak power in the countermovement jump (447 +/- 248 W; ES: 0.94) were observed following the 12-week training period. Greater strength increases were observed as a result of the eccentric training modalities (ES: 0.72-1.09) with no effect of the overspeed stimuli on these measures (p > 0.05). Eccentric training with overspeed stimuli was more effective than traditional resistance training in increasing peak power in the countermovement jump (94 +/- 55 W; ES: 0.95). Eccentric training induced no beneficial training response in maximal running speed (p > 0.05); how-ever, the addition of overspeed exercises salvaged this relatively negative effect when compared with eccentric training alone (0.03 +/- 0.01 seconds; ES: 1.33). These training results achieved in 3-week training blocks suggest that it is important to target-specific aspects of both force and movement velocity to enhance functional measures of power expression.
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| 7. |
- Gaviglio, Christopher M, et al.
(författare)
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Salivary testosterone and cortisol responses to four different rugby training exercise protocols
- 2015
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Ingår i: European Journal of Sport Science. - : Informa UK Limited. - 1746-1391 .- 1536-7290. ; 15:6, s. 497-504
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Tidskriftsartikel (refereegranskat)abstract
- This study assessed the acute response of salivary testosterone and cortisol concentrations to four exercise protocols in 27 elite male rugby players. Each athlete completed four protocols in random order on separate in-season weeks. Two protocols were resistance training based consisting of four exercises (high pull, bench press, squat and chin-ups/prone row): Protocol 1 consisted of 5 sets of 15 repetitions at 55% of 1 repetition maximum (1 RM) with 1-minute rest (5 x 15-55%). Protocol 2 consisted of three sets of five repetitions at 85% 1 RM with 2-minute rest (3 x 5-85%). Protocol 3 was a strongman (STRNG) session consisting of three stations within a circuit of exercises that included exercises such as battling ropes, prowler push, farmer's walk and tyre flips. Protocol 4 was based on boxing and wrestling inspired exercises (combative - COMB). Salivary testosterone and cortisol concentrations were measured before (PRE) and immediately after exercise (POST). Testosterone did not significantly change as a result of any intervention, whereas cortisol declined and the testosterone to cortisol (T/C) ratio increased significantly in both the 5 x 15-55% and 3 x 5-85% protocol. When results were retrospectively grouped and analysed according to the protocol that demonstrated the greatest absolute testosterone response, significant (P < 0.01) increases for the 5 x 15-55%, STRNG and COMB protocols were observed. The individualised hormone response to exercise observed in this study highlights the importance of recognising a protocol-dependent approach to training athletes. Furthermore this study also highlights a potential usefulness of employing STRNG and COMB training protocols as an alternative stimulus to resistance training.
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| 8. |
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