A 60 Days Head Down Tilt Bedrest With Artificial Gravity and Cycling Exercise on 24 Healthy Male (BRACE)

60 days of strict head down tilt bed rest at all time. No countermeasure program is performed.

"60 days of strict head down tilt bed rest at all time. The exercise starts at 40% of VO2max for 5 minutes, followed by a series of 2-minute high- and low-intensity intervals for 20 minutes. 2-minute high-intensity intervals are at 65% VO2max, 70% VO2max, 80% VO2max, 80% VO2max, 70% VO2max and 65% VO2max. 2-minute low-intensity intervals are at 40% VO2max. 3 minutes at 40% of VO2max will end the exercise.~VO2max is measured for each volunteer in supine position."

"60 days of strict head down tilt bed rest at all time. The exercise starts at 40% of VO2max for 5 minutes, followed by a series of 2-minute high- and low-intensity intervals for 20 minutes. 2-minute high-intensity intervals are at 65% VO2max, 70% VO2max, 80% VO2max, 80% VO2max, 70% VO2max and 65% VO2max. 2-minute low-intensity intervals are at 40% VO2max. 3 minutes at 40% of VO2max will end the exercise.~VO2max is measured for each volunteer in supine position.~The supine bike exercise is performed in a short arm centrifuge in rotation. Volunteers will start pedalling and the centrifuge will start at 0.15 Gz less than individual's threshold.~Every 4 minutes thereafter, the AG will be increased by 0.15 Gz, synchronized with the ramping up of cycle ergometer interval intensity. The AG will increase only up to 70 % of their tolerance level,.~It will then decrease by 0.15 Gz every 4 minutes, and until the 30-minute exercise is completed."