# Sleep Quality Impacts Training Responses and Performance in Elite Swimmers

## TL;DR

This study shows that better sleep quality in elite swimmers leads to improved training responses and faster swimming performance.

## Contribution

The study demonstrates a novel link between sleep quality and swimming performance in elite athletes.

## Key findings

- Higher sleep quality is associated with lower average workout strain and heart rates in swimmers.
- Greater sleep duration and slow-wave sleep percentage predict faster swimming performance.
- Sleep quality measures are linked to training adaptations and performance outcomes.

## Abstract

High‐quality sleep is necessary for optimal health and promoting recovery from training, contributing to sport performance. Research suggests a high prevalence of poor sleep duration and quality in athletes. Reduced sleep duration has been shown to be deleterious to performance, but less is known about sleep quality and its relationship to training responses and performance. In 26 elite male (n = 10) and female (n = 16) collegiate swimmers, we assessed sleep quality (sleep duration (hrs), sleep debt (hrs), slow‐wave sleep (SWShrs and SWS%), rapid‐eye movement (REMhrs and REM%)), training measures (strain (AU), average heart rate (HR) (ExHRavg) and maximum exercising HR (ExHRmax)), and swimming performance (200yd time trial swim) during heavy training, preceding championship competition. Collection of sleep data was matched to days of training data collection, and also to the day preceding the performance swim. Pearson correlations were utilized to determine relationships between variables unless sex effects existed in which case linear regression analyses were utilized to control for sex differences in variables. In all swimmers, sleep duration is related to strain (R = −0.78; p = 0.01), and sleep debt is related to ExHRavg (R = 0.53; p = 0.005). SWShrs negatively is related to ExHRavg (R = −0.42; p = 0.032). Controlling for sex, sleep duration predicted swimming performance (R
2 = 0.881; p < 0.001), swimmers with greater sleep durations exhibited faster swim race times. Similarly, when controlling for sex, SWS% predicted swimming performance (R
2 = 0.883; p < 0.001), swimmers with greater SWS% exhibited faster times. Sleep quality measures were related to training adaptations and swimming performance was predicted by sleep quantity and quality. Athletes should obtain adequate sleep to support recovery and optimize training and performance.

Sleep quality was related to both training responses and swimming performance in all swimmersSwimmers with higher sleep quality exhibited lower average workout strain and heart rates during trainingSwimmers with higher sleep quality exhibited faster swimming performance during the time trial swim.

Sleep quality was related to both training responses and swimming performance in all swimmers

Swimmers with higher sleep quality exhibited lower average workout strain and heart rates during training

Swimmers with higher sleep quality exhibited faster swimming performance during the time trial swim.