Resistance Exercise Plus Nutrition Benefits Bone in Long-Duration Spaceflight
F REY Aviat Space Environ Med 2013; 84:262 – 3.
Loss of bone mineral density, architecture (structure), and strength
during spaceflight, especially long-duration spaceflight, is a serious
problem that could put astronauts at risk in gravitational environ-
ments such as the Moon or Mars and would definitely pose a risk on
return to Earth after exploration space missions. Efforts to develop
countermeasures to mitigate this problem, such as exercise — which to
date have been primarily aerobic (treadmill or cycle) and muscle
endurance exercises — have produced little success. However, more
recent ground-based research using subjects on bed rest (an analogue
of spaceflight) has shown that resistance exercise that exerts an ade-
quate load on bone can mitigate bone loss. Energy restriction on Earth
has also been shown to be associated with negative impacts on bone
health. This report describes recent progress in addressing these inade-
quacies and the effectiveness of these changes in exercise and dietary
countermeasures in benefitting astronauts ’ bones.
Dietary intake: Energy intake in ARED subjects averaged 91% of
predicted requirements compared to iRED at 78%. Higher intake of
protein or energy (individually) correlated with increased bodyweight
and less loss of pelvic BMC (the pelvis being a large skeleton region,
this supports the fact that adequate energy intake is required for
bone health).
