Related Experiment Video
Updated: Aug 5, 2026
08:36
Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments
Published on: August 8, 2019
Delaying Early Morning Training Time in Swimmers: Effects on Sleep, Recovery and Performance-A Randomized Controlled
Maxime M E Brandts1, Sabrina Forster2, Anne Hecksteden3,4
1Institute of Sports and Preventive Medicine, Saarland University, Saarbrücken, Germany. maxime.brandts@uni-saarland.de.
Sports Medicine - Open
|July 28, 2026
Summary
Delaying elite swimmers' early morning training increased sleep duration but did not improve recovery or performance. This highlights persistent sleep challenges for adolescent swimmers despite schedule adjustments.
Area of Science:
- Sports Science
- Sleep Research
- Adolescent Health
Background:
- Swimmers frequently experience insufficient sleep due to early morning training schedules.
- Later wake-up times offer a potential strategy to extend sleep duration and mitigate negative impacts.
Purpose of the Study:
- To investigate the effects of delaying early morning swim training on sleep, recovery, and performance.
- To determine if sleep changes mediate the impact of training schedules on recovery and performance.
Main Methods:
- A crossover design study involving 27 national-level swimmers over two 8-day training camps.
- Sleep and recovery were monitored using actigraphy and questionnaires, while performance was assessed via time trials.
- Statistical analyses included linear mixed-effects models and mediation analysis to examine training time effects.
Main Results:
- Delaying training from 7 AM to 9 AM significantly increased sleep duration by approximately one hour.
- No significant improvements were observed in recovery measures or performance in 100m and 800m time trials.
- Mediation analysis revealed no indirect effects of sleep duration or mental capacity on performance.
Conclusions:
- While delaying training boosts sleep duration in swimmers, it does not enhance recovery or performance.
- Early morning training is linked to reduced sleep, underscoring ongoing sleep issues for adolescent swimmers.
- The study emphasizes the need for further research into optimizing training schedules for elite young athletes.
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