Mechanical muscle function, morphology, and fiber type in lifelong trained elderly.
OBJECTIVE
Maximal muscle contraction force and muscle mass are both reduced during the natural aging process. Long-term training may be used to attenuate this age-related loss in muscle function and muscle size.


METHODS
Maximum isometric quadriceps strength (MVC), rate of force development (RFD), and muscle fiber composition and size (CSA) were studied in elderly individuals (68-78 yr) chronically exposed (> 50 yr) to either endurance (E) or strength (S) training, and in age-matched, untrained (U) elderly group.


RESULTS
E and S showed greater MVC than did U. Contractile RFD was elevated in S compared with U, and S also demonstrated greater type II fiber CSA than did U and E. The proportion of type I fibers was greater in E compared with U and S.


CONCLUSIONS
Muscle fiber size and mechanical muscle performance, particularly RFD, were consistently elevated in aged individuals exposed to chronic (i.e., lifelong) strength training. This relative preservation in muscle morphology and function may provide an important physical reserve capacity to retain muscle mass and function above the critical threshold for independent living at old age.
Aagaard
Per
P
Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark. paagaard@health.sdu.dk
Magnusson
Peter S
PS
Larsson
Benny
B
Kjaer
Michael
M
Krustrup
Peter
P
D000368:Aged; D003718:Denmark; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D018485:Muscle Fibers, Skeletal / Q000502:physiology*; D052097:Quadriceps Muscle / Q000033:anatomy & histology / Q000502:physiology*