Exogenous Ketosis Improves Sleep Efficiency and Counteracts the Decline in REM Sleep after Strenuous Exercise.

"This study was funded by Research Fund Flanders (Fonds voor Wetenschappelijk Onderzoek—Vlaanderen; research grant no. G089221N). C. P. is supported by an FWO Postdoctoral Research Grant (1244921N). The authors declare that they have no competing interests. The results of the study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation. The results of the present study do not constitute endorsement by the American College of Sports Medicine."

"This study was funded by Research Fund Flanders (Fonds voor Wetenschappelijk Onderzoek—Vlaanderen; research grant no. G089221N). C. P. is supported by an FWO Postdoctoral Research Grant (1244921N). The authors declare that they have no competing interests. The results of the study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation. The results of the present study do not constitute endorsement by the American College of Sports Medicine."

"Before participation, subjects were examined by a qualified physician using a medical questionnaire and a resting electrocardiogram. People working in late-night shifts and extreme morning and evening chronotypes as determined by the Horne and Östberg questionnaire () were excluded from participation. Subjects were also free of psychological and neurological disorders, including depression and anxiety, as assessed using the Beck’s Depression () and Anxiety () questionnaires. None of the subjects had sleep disorders and reported good sleep quality (Pittsburgh Sleep Quality Index score <5), were nonsmokers, and did not take any medication that could interfere with either sleep or exercise performance. None of the subjects followed a high-fat, low-carbohydrate, ketogenic diet or consumed ketotic supplements during the last 3 months before the study. Ten well-trained male cyclists with good sleep quality (age: 23 ± 4 yr (mean ± SD); body mass: 70.7 ± 4.8 kg; height: 1.79 ± 0.05 m; lactate threshold (LT): 267 ± 38 W; V̇O2max: 62.9 ± 7.2 mL·kg−1·min−1) and an average cycling volume of 10.8 ± 4.4 h·wk−1 met the inclusion criteria and signed the written informed consent before participation. The study was approved by the Ethics Committee Research UZ/KU Leuven (B3222021000492) and complies with the Declaration of Helsinki (registered at www.clinicaltrials.gov as NCT05439720)."