Acute Effect of Exogenous Ketosis on Sleep Architecture Following Strenuous Exercise

Acute Effect of Exogenous Ketosis on Sleep Architecture Following Morning and Evening Strenuous Exercise

The aim of this study is to investigate the effect of oral ketone ester administration on sleep architecture. To investigate this, the investigators use a randomised, placebo-controlled, cross-over research design. The study comprises three experimental sessions, each separated by a one-week washout period. Two of the three experimental sessions consist of a 120 minutes cycling endurance training session (ET) two hours after breakfast and an evening high-intensity-interval training (HIIT) ending one hour before bedtime. After each training session, and 30 minutes before sleeptime, subjects receive a ketone ester or a control drink . To investigate the effects of strenuous exercise on sleep alone, an additional experimental session without exercise is added.

Before bedtime, a venous blood sample is taken to evaluate hormones playing an important role in sleep regulation. During the experimental sessions, the subjects sleep in a sleep facility to evaluate quality of sleep. Time spent in different sleep phases is measured via polysomnography (PSG). Urine output throughout the day and night will be collected for measurement of urinary excretion of adrenaline and noradrenaline as an index of intrinsic sympathetic activity.

Inclusion Criteria:

• Males between 18 and 35 years old
• Recreational or competitive cyclists performing regularly cycling training sessions with an average training volume of more than 6 hours per week
• Good health status confirmed by a medical screening
• Body Mass Index (BMI) between 18 and 25
• Normal sleep pattern as assessed by the Pittsburgh Sleep Quality Index (PSQI)
• Moderate sleep chronotype, assessed by the Horne and Östberg questionnaire

Exclusion Criteria:

• Excessive daytime sleepiness as assessed by the Epworth scale
• Depression or anxiety as assessed by the Beck Depression Inventory and Beck Anxiety Inventory
• Night-shifts or travel across time zones in the month preceding the study
• Any kind of injury/pathology that is a contra-indication to perform high-intensity exercise
• Intake of any medication or nutritional supplement that is known to affect exercise performance or sleep
• Smoking
• Involvement in elite athletic training at a semi-professional or professional level
• Current participation in another research trial
• Any other argument to believe that the subject is unlikely to successfully complete the full study protocol