To assess cardiovascular functional performance, maximum aerobic capacity was measured in each subject before and after bed rest using a graded cycle exercise test. The peak maximal test was performed on an upright cycle ergometer on each bed rest subject to assess cardiovascular health and aerobic fitness.
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Maximal aerobic capacity was assessed in each subject before and immediately after bed rest using a graded cycle exercise test. Subjects pedaled a cycle ergometer at increasing work loads of 50-350 Watts while heart rate, blood pressure, and oxygen uptake were monitored. Peak cycle exercise tests were conducted prior to bed rest and following bed rest. The test measured metabolic gas analysis parameters, blood pressure, workloads, and perception of effort (RPE). From these measures peak heart rate (HR) and peak oxygen consumption (VO2) were established.
Subject began with a very low workload as a warm-up. The workload was gradually increased in an incremental manner until maximal exertion was reached. The protocol was appropriately configured to the body size and fitness level of the subject such that maximal exercise was reached in approximately 8-15 minutes. The first stage lasted three minutes and was set at a light workload. Each subsequent stage was one minute in duration and the workload was gradually increased until the subject reached peak effort. During the exercise test the subject was asked to wear a nose clip and breathe in and out of a special mouthpiece. The expired air was analyzed for various fitness related parameters. The upright cycle ergometer test was performed at each session to measure HR and VO2. Blood pressure, workloads, and RPE were also measured.
Results from the Artificial Gravity (AG) Pilot Study indicate that bed rest decreased peak VO2 in the control group while the AG treatment attenuated this drop. The mean peak VO2 after bed rest was 12% lower than pre-bed rest in the control group but was 6% lower in the treatment group. When these results were expressed relative to body weight, there tended to be a group by bed rest interaction in peak VO2.
Summarized results for the other missions aren't available.
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Carbon dioxide expired (FECO2)
Carbon dioxide production (VCO2)
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Diastolic blood pressure
Heart rate (HR)
Oxygen expired (FEO2)
Peak oxygen consumption (VO2)
Perception of effort (RPE)
Respiratory exchange ratio (RER)
Systolic blood pressure
Ventilation exchange (VE)