Australian Football is an intense team sport played over ~120 min on a weekly basis. To determine the effects of game and training load on muscle soreness and the time frame of soreness dissipation, 64 elite Australian Football players (age 23.8 ± 1.8 y, height 183.9 ± 3.8 cm, weight 83.2 ± 5.0 kg; mean ± SD) recorded perceptions of muscle soreness, game intensity, and training intensity on scales of 1–10 on most mornings for up to 3 competition seasons. Playing and training times were also recorded in minutes. Data were analyzed with a mixed linear model, and magnitudes of effects on soreness were evaluated by standardization. All effects had acceptably low uncertainty. Game and training-session loads were 790 ± 182 and 229 ± 98 intensity-minutes (mean ± SD), respectively. General muscle soreness was 4.6 ± 1.1 units on d 1 postgame and fell to 1.9 ± 1.0 by d 6. There was a small increase in general muscle soreness (0.22 ± 0.07–0.50 ± 0.13 units) in the 3 d after high-load games relative to low-load games. Other soreness responses showed similar timelines and magnitudes of change. Training sessions made only small contributions to soreness over the 3 d after each session. Practitioners should be aware of these responses when planning weekly training and recovery programs, as it appears that game-related soreness dissipates after 3 d regardless of game load and increased training loads in the following week produce only small increases in soreness.
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Paul G. Montgomery and Will G. Hopkins
David K. Liow and Will G. Hopkins
The training practices of athletes with disabilities were investigated by means of a validated self-administered questionnaire. Descriptive statistics were derived from the replies of 41 wheelchair racers, 20 swimmers, and 14 athletes specializing in throwing events. The majority of athletes competed at either international (77%) or national levels (15%). Almost all swimmers were coached frequently, but one third of the wheelchair racers and one half of the throwers were not coached. Median volumes of endurance, interval, strength, and skill training in each of four training phases (buildup, precompetition, taper, and postcompetition) only partially reflected the contribution of energy systems and skills to performance in the different sports; moreover, there were wide variations in the training programs of athletes within each sport, especially swimmers and throwers. It was concluded that there is need for improvement in the coaching and training of many top-class athletes with disabilities.
David S. Rowlands and Will G. Hopkins
The effect of pre-exercise meal composition on metabolism and performance in cycling were investigated in a crossover study. Twelve competitive cyclists ingested high-fat, high-carbohydrate, or high-protein meals 90 min before a weekly exercise test. The test consisted of a 1-hour pre-load at 55% peak power, five 10-min incremental loads from 55 to 82% peak power (to measure the peak fat-oxidation rate), and a 50-km time trial that included three 1-km and 4-km sprints. A carbohydrate supplement was ingested throughout the exercise. Relative to the high-protein and high-fat meals, the high-carbohydrate meal halved the peak fat-oxidation rate and reduced the fat oxidation across all workloads by a factor of 0.20 to 0.58 (p = .002–.0001). Reduced fat availability may have accounted for this reduction, as indicated by lower plasma fatty acid, lower glycerol, and higher pre-exercise insulin concentrations relative to the other meals (p = .04–.0001). In contrast, fat oxidation following the high-protein meal was similar to that following the high-fat meal. This similarity was linked to evidence suggesting greater lipolysis and plasma fat availability following high-protein relative to high-carbohydrate meals. Despite these substantial effects on metabolism, meal composition had no clear effect on sprint or 50-km performance.
Fabio R. Serpiello and Will G. Hopkins
Purpose: To assess the convergent validity of internal load measured with the CR100 scale in youth football players of 3 age groups. Methods: A total of 59 players, age 12–17 years, from the youth academy of a professional football club were involved in this study. Convergent validity was examined by calculating the correlation between session ratings of perceived exertion (sRPE) and Edwards load, a commonly used load index derived from the heart rate, with the data originating from 1 competitive season. The magnitude of the relationship between sRPE and Edwards load was obtained with weighted mean correlations and by assessing the effect of the change of the Edwards load on sRPE. Differences between the individuals’ intercepts and slopes were assessed by interpreting the SD representing the random effects (player identity and the interaction of player identity and scaled Edwards load). Probabilistic decisions about true (infinite sample) magnitudes accounting for sampling uncertainty were based on 1-sided hypothesis tests of substantial magnitudes, followed by reference Bayesian analysis. Results: Very high relationships exist between the sRPE and Edwards load across all age groups, with no meaningful differences in the magnitudes of the relationships between groups. Moderate to large differences between training sessions and games were found in the slopes of the relationships between the sRPE and Edwards load in all age groups. Finally, mostly small to moderate differences were observed between individuals for the intercepts and slopes of the relationships between the sRPE and Edwards load. Conclusion: Practitioners working in youth team sports can safely use the CR100 scale to track internal load.
Kathryn E. Phillips and Will G. Hopkins
Purpose: To further the understanding of elite athlete performance in complex race environments by examining the changes in cyclists’ performance between solo time trials and head-to-head racing in match-sprint tournaments. Methods: Analyses were derived from official results of cyclists in 61 elite international sprint tournaments (2000–2016), incorporating the results of 2060 male and 1969 female head-to-head match races. Linear mixed modeling of log-transformed qualification and finish ranks was used to determine estimates of performance predictability as intraclass correlation coefficients. Correlations between qualifying performance and final tournament rank were also calculated. Chances of winning head-to-head races were estimated adjusting for the difference in the cyclists’ qualifying times. All effects were evaluated using magnitude-based inference. Results: Minor differences in predictability between qualification time trial and final tournament rank were suggestive of more competitiveness among men in the overall tournament. Performance in the qualification time trial was strongly correlated with, but not fully indicative of, performance in the overall tournament. Correspondingly, being the faster qualifier had a large positive effect on the chances of winning a head-to-head race, but small substantial differences between riders remained after adjustment for time-trial differentials. Conclusions: The present study provides further insight into how real-world competition data can be used to investigate elite athlete performance in sports where athletes must directly interact with their opponents. For elite match-sprint cyclists, qualifying time-trial performance largely determines success in the overall tournament, but there is evidence of a consistent match-race ability that modifies the chances of winning head-to-head races.
Darrell L. Bonetti and Will G. Hopkins
To estimate variability in performance time and smallest worthwhile changes for elite fat-water canoeists competing in 200-, 500- or 1000-m events at international regattas.
The data came from A and B finals held at 7 to 13 regattas in 2003 to 2007. A linear mixed-model analysis of log-transformed official race times provided estimates of variability as coefficients of variation and included terms to account for changes in performance between years, venues, and A and B finals.
For men, the within-athlete variation in A finals was similar in canoeing and kayaking events, with the 200-m men’s events demonstrating probably less variability than the longer events (by an overall factor of 0.75, ×/÷1.33) that may reflect differences in pacing strategies. In contrast, the within-athlete variation for women kayakers in A finals of the 500-m event was only half that of the other distances (ratio 0.54, ×/÷1.29), possibly because of differences in competitive experience or depth of competition. Predictability of performance in A finals was moderate to very high (interclass correlations 0.40 to 0.89). Within-athlete variation in the B finals was generally greater than in the A finals for the three distances for men, but there was no clear pattern for women.
The smallest worthwhile changes in performance time (0.3× within-athlete variability) in canoeing and kayaking are approx. 0.3% to 0.6%. Effects of 1% to 2% in power output would be required to achieve such changes in this generally highly predictable sport.
Will G. Hopkins and Alan M. Batterham
Kathryn E. Phillips and Will G. Hopkins
To explore the extent to which factors that determine performance transfer within and between time-trial and mass-start events in the track-cycling Omnium.
Official finish rank in the 3 time-trial events, in the 3 mass-start events, and in the competition overall were collated in 20 international Omnium competitions between 2010 and 2014 for 196 male and 140 female cyclists. Linear mixed modeling of the log-transformed finish time for the time-trial events and of log-transformed finish rank for all events and final rank provided estimates of within-athlete race-to-race changes in performance and average betweenathletes differences across a season. These estimates were converted to various correlations representing relationships within and between the various events and final rank.
Intraclass correlation coefficients, representing race-to-race reproducibility of performance, were similar whether derived from finish rank or finish time for the time-trial events. Log-transformed finish ranks are therefore a suitable measure to assess and compare performance in time-trial and mass-start events. Omnium cyclists were more predictable in their performances from race to race in the timed events, whereas reduced predictability was observed in mass-start events. Interevent correlations indicated stronger links in performance between the timed disciplines, whereas performance in any of the mass-start events had only a slight positive relationship with performance in the other massstart events and little or no relationship with the timed events.
Further investigation is warranted to determine whether factors related to performance in mass-start events can be identified to improve reproducibility or whether variability in performance results from random chance.
David B. Pyne, Megan E. Anderson, and Will G. Hopkins
To characterize within-subject changes in anthropometric characteristics of elite swimmers within and between seasons.
The subjects were 77 elite swimmers (31 females, 46 males, age 15 to 30 years) monitored over 0.4 to 9.2 years. One anthropometrist recorded their body mass (M) and sum of 7 skin-fold thicknesses (S) on 2042 occasions over 14 years from phase to phase within a season and over consecutive seasons. We estimated change in lean mass using a newly derived index (LMI) that tracked changes in M controlled for changes in S.
The LMI is M/Sx, where x = 0.16 ± 0.04 for females and 0.15 ± 0.05 for males (mean ± SD). The LMI of males increased 1.1% (95% confidence limits ± 0.2%) between preseason and taper phases, almost twice as much as that of females (0.6% ± 0.3%). During the same period, M and S fell by ~1% and ~11%, respectively. From season to season LMI increased by 0.9% (0.8% to 1.0%) for males and 0.5% (0.3% to 0.7%) for females. All these within-subject effects on LMI were well defined (±~0.3%). The typical variation (SD) of an individual’s LMI was 1.2% for assessments within a season and 1.9% between seasons, with a short-term technical error of measurement of ~0.5%.
Coaches and conditioners should typically expect a twofold greater increase in lean mass in male swimmers within and between seasons than in females. An LMI of the form M/Sx should be useful for monitoring individual swimmers and athletes in other sports in which body composition affects performance.
Darrell L. Bonetti, Will G. Hopkins, and Andrew E. Kilding
Live-high train-low altitude training produces worthwhile gains in performance for endurance athletes, but the benefits of adaptation to various forms of artificial altitude are less clear.
To quantify the effects of intermittent hypoxic exposure on kayak performance.
In a crossover design with a 6-week washout, we randomized 10 subelite male sprint kayak paddlers to hypoxia or control groups for 3 weeks (5 days/week) of intermittent hypoxic exposure using a nitrogen-filtration device. Each day's exposure consisted of alternately breathing hypoxic and ambient air for 5 minutes each over 1 hour. Performance tests were an incremental step test to estimate peak power, maximal oxygen uptake, exercise economy, and lactate threshold; a 500-m time trial; and 5 × 100-m sprints. All tests were performed on a wind-braked kayak ergometer 7 and 3 days pretreatment and 3 and 10 days post treatment. Hemoglobin concentration was measured at 1 day pretreatment, 5 and 10 days during treatment, and 3 days after treatment.
Relative to control, at 3 days post treatment the hypoxia group showed the following increases: peak power 6.8% (90% confidence limits, ± 5.2%), mean repeat sprint power 8.3% (± 6.7%), and hemoglobin concentration 3.6% (± 3.2%). Changes in lactate threshold, mean 500-m power, maximal oxygen uptake, and exercise economy were unclear. Large effects for peak power and mean sprint speed were still present 10 days posthypoxia.
These effects of intermittent hypoxic exposure should enhance performance in kayak racing. The effects might be mediated via changes in oxygen transport.