The Influence of Muscle Fiber Typology on the Pacing Strategy of 200-m Freestyle Swimmers

Pacing Strategies in Elite Individual-Medley Swimmers: A Decision-Tree Approach

PURPOSE

This study aimed to examine pacing strategies and identify the stroke that has the most significant impact on overall performance in men's and women's 200-m and 400-m individual-medley events from 2000 to 2021.

METHODS

The time in each lap and overall race was retrieved from the World Aquatics website. The standardized time for each stroke in individual medley was calculated by dividing the actual time by a reference time specific to each stroke. The reference time was derived from the respective laps in single-stroke finals in the 2017 World Swimming Championships. The decision-tree method was used for analysis. The dependent variables were qualified or nonqualified in heats and semifinals, and winning medals in finals. The independent variables were the ratio of standardized time in each stroke to the sum of standardized time in all 4 strokes.

RESULTS

Swimmers who spent a higher ratio of standardized time in the butterfly stroke (>0.236-0.245) are associated with a higher likelihood of winning medals or qualifying for the next stage in most men's and women's 200-m and 400-m individual medley. Butterfly exhibited the highest normalized importance that distinguished medalists from nonmedalists in the finals. The front-crawl stroke is the second most important determinant in medalists in men's and women's 200-m individual medley, whereas backstroke and breaststroke were the second most important in men's and women's 400-m individual medley, respectively.

CONCLUSION

Individual-medley swimmers who were excellent in butterfly and conserved energy in butterfly had a higher likelihood of success.

Pacing Behavior Development in Adolescent Swimmers: A Large-Scale Longitudinal Data Analysis

PURPOSE

This study aimed to use a large-scale longitudinal design to investigate the development of the distribution of effort (e.g., pacing) in adolescent swimmers, specifically disentangling the effects of age and experience and differentiating between performance levels in adulthood.

METHODS

Season best times and 50-m split times of 100- and 200-m freestyle swimmers from five continents were gathered between 2000 and 2021. Included swimmers competed in a minimum of three seasons between 12 and 24 yr old (5.3 ± 1.9 seasons) and were categorized by performance level in adulthood (elite, sub-elite, high-competitive; 100-m: n = 3498 (47% female); 200-m: n = 2230 (56% female)). Multilevel models in which repeated measures (level 1) were nested within individual swimmers (level 2) were estimated to test the effects of age, race experience, and adult performance level on the percentage of total race time spent in each 50-m section ( P < 0.05).

RESULTS

In the 100-m, male swimmers develop a relatively faster first 50-m when becoming older. This behavior also distinguishes elite from high-competitive swimmers. No such effects were found for female swimmers. Conversely, more experienced male and female swimmers exhibit a slower initial 50-m. With age and race experience, swimmers develop a more even velocity distribution in the 200-m. Adolescent swimmers reaching the elite level adopt a more even behavior compared with high-competitive. This differentiation occurs at a younger age in female (>13 yr) compared with male (>16 yr) swimmers.

CONCLUSIONS

Pacing behavior development throughout adolescence is driven by age-related factors besides race experience. Swimmers attaining a higher performance level during adulthood exhibit a pacing behavior that better fits the task demands during adolescence. Monitoring and individually optimizing the pacing behavior of young swimmers is an important step toward elite performance.

The Relevance of Muscle Fiber Type to Physical Characteristics and Performance in Team-Sport Athletes

PURPOSE

The aim of this systematic review was to (1) determine the muscle fiber-type composition (or muscle fiber typology [MFT]) of team-sport athletes and (2) examine associations between MFT and the physical characteristics and performance tasks in team-sport athletes.

METHODS

Searches were conducted across numerous databases-PubMed, SPORTDiscus, MEDLINE, and Google Scholar-using consistent search terms. Studies were included if they examined the MFT of team-sport athletes. Included studies underwent critical appraisal using the McMasters University critical appraisal tool for quantitative research.

RESULTS

A total of 10 studies were included in the present review, wherein the MFT of athletes was measured from 5 different team sports (soccer, rugby union, rugby league, handball, and volleyball). There was large variability in the MFT of team-sport athletes both within (up to 27.5%) and between sports (24.0% relative difference). Male football players with a higher proportion of type II fibers had faster 10- and 30-m sprint times, achieved a greater total distance sprinting (distance at >6.67 m·s-1), and a greater peak 1-minute sprint distance.

CONCLUSIONS

MFT varies considerably between athletes both within and between different team sports. The results from some studies suggest that variation in MFT is associated with high-intensity running performance in a football match, as well as 10- and 30-m sprint times. Further experimental studies should focus on how determination of the MFT of team-sport athletes could be utilized to influence talent identification, team selection, and the individualization of training.