Muscle strengthening through high-resistance weight training in patients with neuromuscular disorders.

The effects of weight training on muscle performance were quantified by measuring (1) maximum force (muscle strength), (2) force-time integral--area under force-time plot during 60 seconds of sustained maximum force (work done), and (3) fatigue index--percentage reduction in maximum force. Subjects included 16 patients with gradually progressive neuromuscular disorders. The muscle strength of these patients ranged from 2% to 75% normal before the program. For patients with markedly to moderately weak muscles, maximum force increased by 80% +/- 48%, force-time integral increased by 132% +/- 93%, and mean fatigue index was significantly reduced from 53% +/- 18% to 34% +/- 7.7% during the study period. Severely weak muscles (less than 10% normal strength) generally did not improve. High-resistance weight training can significantly increase muscle performance of patients with neuromuscular disease if disease progression is slow and initial muscle strength is greater than 15% normal.