Hormonal and biochemical changes in trained and untrained subjects during and after exposure to a 30 days bed rest period

The objective of this investigation was to determine the hormonal and kallikrein‐kinin‐system (KKS) activity, and the clotting and fibrinolytic system changes in trained and untrained subjects during 30 days of a bed rest (BR) period and during 15 days of a postbedrest (PBR) period. 20 endurance trained male volunteers with a peak VO2 60.9 mL.min−1.kg−1 and 20 untrained male healthy volunteers with a peak VO2 of 39.9 mL.min−1.kg−1 were chosen as subjects. They had an age range from 19 to 24 years All volunteers were divided into four equal groups: Ten trained subjects were kept under a rigorous bedrest regime and served as bedrested trained subjects (BTS). Ten trained subjects were placed continuously on a regime of exercise of 13.8 km ‐ day and served as control trained subjects (CTS). Ten untrained subjects were kept under a rigorous bed rest regime and served as bedrested untrained subjects (BUS). Ten untrained subjects were placed continuously on a regime of exercise of 6.3 km · day and served as cont...