Impact of Sleep–wake Patterns and Daily Rhythms Including Training on Midsleep Time in Adolescent Basketball Players During the COVID-19 Pandemic

Objectives The coronavirus disease (COVID-19) had a major impact on sleep and training behavior in adolescent athletes. A crucial sleep parameter is midsleep time, which illustrates the midpoint between sleep onset and offset. The aim of this investigation was to examine the impact of chronotype, age, sex, pandemic phase, weekend, and training habits on midsleep time. The sample consisted of German elite adolescent basketball athletes ( N = 91, 15.75 ± 1.15 years, female = 39.46%). Method Data were collected through a 10-day subjective monitoring program during three different pandemic phases, with more severe restrictions in phase 1. In total, 1146 measurement points were analyzed. A linear mixed model approach was used for the evaluation. Results A negative linear association between chronotype and midsleep time was revealed. A negative effect was identified for phases 2 and 3. The weekend parameter showed a positive effect, which may illustrate the occurrence of social jetlag. The main finding of this investigation is that a morning chronotype distribution was associated with earlier midsleep timing throughout the entire survey period. Conclusion The results acknowledge that chronotype is one of the main influencing parameters for midsleep time. The study represents a useful contribution to the research of chronotype and sleep behavior in athletes, with a focus on the major impact of the COVID-19 pandemic.