Two years of resistance training in older men and women: the effects of three years of detraining on the retention of dynamic strength.
Dynamic muscle strength (1-RM) and symptom-limited treadmill endurance were compared among three groups (5 M and 5 F per group) of older adults (mean age 72.5 yrs) who had either weight-trained continuously twice per week for 5 years (Tr), ceased to weight train after 2 years (Detr), or acted as controls throughout (Con). The Tr and Detr trained hard (progressing up to 3 sets at up to 80% of 1-RM) for 2 years; the Tr continued training for an additional 3 years at a maintenance level (2 to 3 sets at 60-70% 1-RM), whereas the Detr stopped training for those 3 years. The Con subjects did not train for the duration of the study but took part in identical testing procedures. After 2 years of resistance training, dynamic strength in the Tr and Detr groups increased significantly above baseline and Con values for all exercises, p < 0.0001. Following 3 years of maintenance level training, arm curl, leg press, and bench press 1-RM (sum of both limbs) in the Tr remained significantly above baseline values (21.6 kg = 17%; 15.7 kg = 82%; 8.3 kg = 34%, respectively). The 1-RM in Detr were 18.4 kg (14%), 5.3 kg (24%), and 1.4 kg (9%) above baseline for leg press, arm curl, and bench press after 5 years, whereas the Con declined over the 5-yr period by 18.4 kg (-9.7%), 4.4 kg (-19%), and 3.5 kg (-6%), respectively. There were nonsignificant improvements in treadmill performance in the Tr and Detr, and a decline in the Con after 2 years. Treadmill performance declined between Years 2 and 5 in all groups despite continued training (ns). We conclude that: (1) dynamic strength gains from 2 years of resistance training in older individuals are not entirely lost even after 3 years of detering; (2) these effects may be specific to the exercises performed in the training program; (3) adoption of maintenance-level moderate-intensity training significantly attenuates the decline in dynamic strength of previously trained muscles.
Smith
Kelly
K
Dept. of Kinesiology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1.
Winegard
Karen
K
Hicks
Audrey L
AL
McCartney
Neil
N
D000368:Aged; D000375:Aging / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010807:Physical Endurance; D013997:Time Factors; D016138:Walking / Q000502:physiology; D014891:Weight Lifting