Skylab Reduced muscle mass, strength and performance in space
figure 6-2. changes in upper , lower limb volumes obtained circumference measurements of 3-cm segments in 3 crewmembers skylab 4. because of higher exercise volume in skylab 4 crewmembers, loss of muscle volume less observed in crewmembers skylab 2 , 3. reference. upper , lower limb volumes obtained on 3 crewmembers of skylab 4 shown in figure 6-2. fluid shifts contributed largest changes lower limb volumes, loss of leg tissue mass evident, particularly in commander. shown in graphs, significant loss of leg volume occurs within first few days of microgravity exposure while changes in upper limbs less remarkable. upon return earth, of loss of leg volume corrected , there short over-correction or overshoot. once fluid shift resolves, true loss of muscle mass remaining in legs revealed more returns baseline or preflight level (see figure 6-2, leg during recovery on right side of graph 3 crewmembers). in skylab 4 commander, loss in leg volume appears 300 cc. (figure 6-2, topmost graph). be...