Article

The aim of this study was to assess the efficacy of long-term
resistance training in preventing the detrimental effects of muscle unloading on neuromuscular function. DESIGN: Eleven untrained men and 11 men with extensive
backgrounds in resistance training were tested for several parameters of
neuromuscular function at various isokinetic contractile velocities before and
after 7 days of muscle unloading. Measurements included muscle mass, strength,
power, total work, electromyography, and neuromuscular transmission efficiency
using superimposed electrical stimulation of maximally contracting muscles.
RESULTS: Muscle performance was superior in resistance-trained subjects before
and after unloading. In both groups of participants, unloading resulted in
significantly (P < 0.05) diminished muscle performance, but only at isometric or
slower isokinetic contractile velocities. Electromyography activity was
significantly higher in trained than in untrained subjects before and after
unloading. Thigh muscle mass was greater among trained subjects before and after
unloading. Neither electromyography activity, thigh muscle mass, nor
neuromuscular transmission efficiency was significantly altered by unloading in
trained or untrained participants. CONCLUSIONS: Chronic resistance training was
found to be ineffective in neutralizing the deleterious effects of unloading on
neuromuscular function. It appears that positive adaptations associated with
long-term resistance training provide no prophylactic effect when neuromuscular
systems are subjected to unloading.

Langue : ANGLAIS