MAINTENANCE OF WHOLE MUSCLE STRENGTH AND SIZE FOLLOWING RESISTANCE TRAINING IN OLDER MEN

Abstract

The purpose of this project was to assess the effectiveness of resistance training (1-d/wk) on the preservation of strength and size gains that were achieved during a 12-wk progressive resistance (PRT) program. Subjects whole muscle strength (1-repetition maximum (1RM)) and whole muscle size (CT Scan) were measured pre (T1) and post (T2) 12 -wk PRT and again following 6 months (T3) of training (TR) or detraining (DTR). During the 12-wk PRT, older men (n = 10; age 70 ± 4 yr.) lifted 3x/wk at 80% of their 1RM. The maintenance group consisted of older men (n = 5; TR) completing 3 sets of 10 repetitions at 80% of their 1 RM 1-d/wk (this was equivalent to a single session that was performed during the 12-wk PRT). The other group of older men (n = 5; DTR) resumed their normal lifestyle (no regular physical activity) following the 12-wk PRT. From T1 to T2 muscle strength increased (p < 0.05) 42% (67 ± 9 to 95 ± 10 kg) in TR and 45% (51 ± 6 to 74 ± 6 kg) in DTR. From T2 to T3, TR was unchanged (96 ± 11 kg), while DTR had decreased (p < 0.05) 9% (67 ± 6 kg). Muscle size demonstrated a similar pattern with a 7% increase (p < 0.05) in both groups from T1 to T2. No change in muscle size was found in TR from T2 to T3, while DTR had a 6% reduction (p < 0.05). These data indicate that resistance training 1-d/wk was sufficient to maintain muscle strength and size in these older men following a 12-wk PRT program. Furthermore the men who resumed their normal lifestyle (no regular physical activity) experienced significant losses in muscle strength and size. Supported by NIH grant AG154876