Leg Strength Declines with Advancing Age Despite Habitual Endurance Exercise in Active Older Adults

Taylor J. Marcell, Steven A. Hawkins, Robert A. Wiswell
2013 Journal of Strength and Conditioning Research  
23 Age-associated loss of muscle mass (sarcopenia) and strength (dynapenia) is associated with a 24 loss of independence that contributes to falls, fractures, and nursing home admissions, while 25 regular physical activity has been suggested to offset these losses. The purpose of this study was 26 to evaluate the effect of habitual endurance exercise on muscle mass and strength in active older 27 adults. A longitudinal analysis of muscle strength (≈ 4.8 yrs apart) was performed on 59 men 28
more » ... ed on 59 men 28 (age at start of study: 58.6±7.3 yr) and 35 women (56.9±8.2 yr) who used endurance running as 29 their primary mode of exercise. There were no changes in fat-free mass while body fat increased 30 minimally (1.0-1.5%). Training volume (km•wk -1 , d•wk -1 ) decreased in both the men and 31 women. There was a significant loss of both isometric knee extension (≈5%/yr) and knee flexion 32 (≈3.6%/yr) strength in both the men and women. However, there was no significant change in 33 either isokinetic concentric or eccentric torque of the knee extensors. Our data demonstrated a 34 significant decline in isometric knee extensor and knee flexor strength while there were no 35 changes in LBM in this group of very active older men and women. Our data support newer 36 exercise guidelines for older Americans suggesting resistance training be an integral component 37 of a fitness program, and that running alone was not sufficient to prevent the loss in muscle 38 strength (dynapenia) with aging. 39 40 Words: 229 41 42
doi:10.1097/jsc.0000000000000208 fatcat:2pdzkym2xrgipdcqhdx7oe4t6y