Resistance exercise maintains skeletal muscle protein synthesis
during bed rest.
Ferrando, Arny A., Kevin D. Tipton, Marcas M. Bamman, and Robert R.
Wolfe.
Metabolism, Shriners Burns Institute, 815 Market St, Galveston TX
77550, KRUG Life Sciences, NASA/Johnson Space Center, Houston TX
77058
APStracts 3:0521A, 1996.
Space flight results in a loss of lean body mass and muscular
strength. A ground-based model for microgravity, bed rest, results in
a loss of lean body mass due to a decrease in muscle protein
synthesis (MPS). Resistance training is suggested as a proposed
countermeasure for space flight-induced atrophy as it is known to
increase both MPS and skeletal muscle strength. We therefore
hypothesized that scheduled resistance training throughout bed rest
would ameliorate the decrease in MPS. Two groups of healthy
volunteers were studied during 14 days of simulated microgravity. One
group adhered to strict bed rest (BR; n = 5), while a second group
engaged in leg resistance exercise every other day throughout bed
rest (BREX; n = 6). Muscle protein synthesis (MPS) was determined
directly by the incorporation of infused L-[ring-13C6]-phenylalanine
into vastus lateralis protein. After 14 days of BR, MPS in the BREX
group did not change and was significantly greater than the BR group.
Thus, moderate resistance exercise can counteract the decrease in MPS
during bed rest.
Received 13 September 1996; accepted in final form 1 November
1996.
APS Manuscript Number A882-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996