LONG-TERM RESISTANCE TRAINING IN THE ELDERLY - EFFECTS ON DYNAMIC STRENGTH, EXERCISE CAPACITY, MUSCLE, AND BONE

We examined the effects of 42 weeks of progressive weight-lifting trai ning on dynamic muscle strength, peak power output in cycle ergometry, symptom limited endurance during progressive treadmill walking and st air climbing, knee extensor cross-sectional areas, and bone mineral de nsity and content in healthy males and females aged 60-80 years, curre ntly enrolled in a 2-year resistance training program. Subjects were r andomized into either exercise (EX) or control (CON) groups (60-70 yea rs: 38 males and 36 females; 70-80 years: 25 males and 43 females). EX trained several muscle groups twice per week for 42 weeks at intensit ies ranging from 50-80% of the load that they could lift once only (1 RM); CON did usual daily activities. After the 10 months there teas no change in 1 RM strength in CON, but significant gains (mean increases up to 65%) in EX (no independent age or gender effects); 30% and 47% of the increase in 1 RM had occurred by 6 and 12 weeks, respectively. In EX, the 7.1% increase in peak cycling power output was significantl y greater than in CON (+1.1%). The 17.8% improvement in symptom limite d treadmill walking endurance was also greater than in CON (+3.4%), bu t the difference between groups during stair climbing was not signific ant (EX + 57%, CON + 33%). The cross-sectional areas of the knee exten sors increased significantly by 5.5% in EX but were unchanged in CON. There were no changes in bone mineral density or content in either gro up. We conclude that long-term resistance training in older people is feasible and results in increases in dynamic muscle strength, muscle s ize, and functional capacity.