FUNCTIONAL TRAINING - MUSCLE STRUCTURE, FUNCTION, AND PERFORMANCE IN OLDER WOMEN

Response to physical training at the cellular and whole muscle level h as been established in older adults, However,the underlying molecular mechanism responsible for change has not been described nor have the r elationships between change in muscle structure and functional perform ance been established. The purpose of this research study is to evalua te the changes of muscle ultrastructure, muscle strength, and whole bo dy Functional performance as a result of a functionally directed exerc ise program (stair climbing). Women (65-83 years old) selected either the control (no exercise; N = 6) or exercise (N = 7) group. The 1-year functionally based exercise program was both aerobic (75% heart rate reserve) and resistive (weighted stair climbing). Muscle ultrastructur e, determined by quantitative morphometry of the vastus lateralis tiss ue, and maximal step-height achieved by each subject were related to i sokinetic strength and muscle morphology. Changes in myofibrillar area accounted for 48% of the variance in muscle strength changes. Change in muscle contractile protein was the underlying basis for change in t high strength which, in turn, was the basis for functional performance . These data provide evidence that, in older women, a mild functionall y based training program results in improved muscle structure and perf ormance of the lower body.