Maintenance of whole muscle strength and size following resistance training in older men.

Following a progressive resistance training (PRT) program of 3 days per week, we sought to examine how effective a resistance training maintenance program of 1 day per week would be to preserve muscle strength and size in older men. Each subject's whole muscle strength (1 repetition maximum, or 1RM) and whole muscle size (determined by computed tomography scan) were measured before (T1) and after (T2) 12 weeks of PRT and again following 6 months (T3) of training (TR) or detraining (DT). During the 12-week PRT, older men (N = 10; age 70 +/- 4 years) trained their knee extensors 3 days per week at 80% of their 1RM. The maintenance program consisted of older men (n = 5; TR; 75 +/- 1 years) who completed 3 sets of 10 repetitions at 80% of their 1RM 1 day per week (this was equivalent to a single training session that was performed 3 days per week during the 12-week PRT). The other group of older men (n = 5; DT; 69 +/- 1 years) resumed their normal lifestyle (no regular physical activity) following the 12-week PRT. From T1 to T2, muscle strength increased (p <.05) 45% (66 +/- 10 to 94 +/- 10 kg) in the TR group and 53% (50 +/- 6 to 74 +/- 7 kg) in the DT group. From T2 to T3, whole muscle strength of the TR group was unchanged (96 +/- 11 kg), whereas strength decreased (p <.05) in the DT group by 11% (66 +/- 6 kg). Muscle size demonstrated a similar pattern with a 7% increase (p <.05) in both groups from T1 to T2. No change in muscle size was found in the TR group from T2 to T3, whereas the DT group had a 5% reduction (p <.05). These data indicate that resistance training 1 day per week was sufficient to maintain muscle strength and size in these older men following a 12-week PRT program. Furthermore, the men who resumed their normal lifestyle (no regular physical activity) experienced significant losses in muscle strength and size.