Physical exercise is well known to improve human health. Current guidelines provide recommendations on the frequency, intensity, type and duration of exercise. However, they do not provide recommendations for the time of day, exercise should be performed. This is surprising considering that the influence of timing of behaviors such as sleep or nutrition as well as the impact of the circadian timing system on health are well documented. Further, there is evidence for diurnal variation in maximum performance which enables individuals to exercise with different intensities at different times of day, which in the long term might affect physical adaptations to exercise. Thus, this research study investigates if exercise timing impacts human health.

Inclusion Criteria:

• BMI 18.5 - 30 kg/m2

Exclusion Criteria:

• Structured resistance training within the last six months
• Ongoing shift work
• Irregular bedtime (> 2 hours variation in habitual bed time)
• Smoking
• Travels across more than two time zones within the last four weeks
• Inability to follow the study procedures (e.g. due to language barriers, psychological disorders, dementia, etc.)
• Known pregnancy or lactating women
• Participation in any other clinical trial within the last four weeks
• Medical condition that is a contra indicator for resistance training, endurance training, or exercising until maximum exhaustion including insufficiently controlled blood pressure (systolic > 170 mmHg, diastolic > 100 mmHg), ongoing cancer treatment, unstable angina pectoris, uncontrolled bradyarrhythmia or tachyarrhythmia, severe uncorrected valvular heart disease, clinically relevant acute infection, any form of musculoskeletal injury, orthopedic problems or decompensated cardiovascular disease
• Insulin dependent diabetes
• Participants using metformin

Anonymized data will be provided in a data repository in accordance to FAIR principles

After completion of study