Functional Training: Muscle Structure, Function, and Performance in Older Women

Abstract

Specificity of training is a well-recognized principle of exercise physiology. Muscles adapt to the specific training stimulus imposed upon them: swimmers train by swimming, weight lifters train by lifting weights, football players train by running and throwing. These strategies have proven effective for athletes; however, they have not been applied to exercise regimes aimed at improving daily activities in older adults. Traditional exercise programs use endurance training, single joint strength training, or a combination of the two, but often they do not produce an improvement in functional measures (3). This traditional a p proach to exercise is prescribed for the general public with the intention of improving activities of daily living, yet they do not incorporate these activities into the training. Although resistance training using machines strengthens each muscle in isolation, these programs do not incorporate integrated performance into the training regime. Functional performance requires the integration of multiple joints and several muscle groups. In an activity such as stair climbing, the integrated strength of the quadriceps, hamstrings, hip flexors and extensors, and plantar flexors is involved. Merely strengthening each muscle in isolation does not train the muscles to work in a coordi- R29-AG10267; R01 AG10853; and ROI AG0754-02; the Dana Foundation; and the American Physiological Society. nated fashion to accomplish a multimuscle task, such as stair climbing.Recent research using resistive training in the older adult has been shown to increase muscle fiber area (4-7) and strength (4-7,12). The changes in strength with resistive training have been attributed to both neural adaptation (12) and muscle hypertrophy (4-7). However, the ultrastructural basis for changes in fiber area has not been investigated in the elderly nor has the ability of these programs to translate into functional performance been reported.The purpose of this study is to evaluate the ability of exercise training to change physical function and to investigate the underlying muscular changes responsible for change in function. This program used stair climbing with weighted backpacks as a resistive training stimulus. Muscle morphology, strength, and lower extremity functional performance were evaluated. Our evaluation incorpo-

Systematic review of functional training on muscle strength, physical functioning, and activities of daily living in older adults

“…Four trials have quality scores of less than 20 [9,17,12,51]. All of these trials were low in the rating of internal validity because of confounding issues, such as applied a nonrandomization design [9,12,51] or failed to address loss to follow-up [17,51]. Table 2 summarizes participant inclusion and exclusion criteria of the 13 trials that were reviewed.…”

“…Chin A Paw et al used game-like and cooperative activities such as throwing and catching a ball as functional training activities [7], while other studies were more focused on exercises simulating locomotor ADL such as walking, stair climbing, or chair stands [9,17,1,12,31,35,47]. Still, other researchers included modified ADL tasks in the functional training component, such as dressing, laundry, vacuuming, or carrying groceries [12,35,11].…”

Lower-extremity biomechanics during forward and lateral stepping activities in older adults

“…Reports from recent, relatively small, randomized clinical trials (n ≤ 45) suggest that exercise programs that include weighted step-up exercises and/or stair-climbing activities can improve lowerextremity strength, muscle power, and bone health in elders (Shaw and Snow, 1998;Cress et al, 1996;Bean et al, 2002).…”

“…To address this concern, geriatricians and exercise specialists are examining the efficacy, adherence, and safety of several novice exercise activities and programs in elders, including Tai Chi (Li et al, 2001;Lan et al, 1998), weighted vest exercise (Greendale et al, 2000;Shaw and Snow, 1998;Snow et al, 2000), squatting activities (Flanagan et al, in press), and stepping/stair climbing programs (Shaw and Snow, 1998;Cress et al, 1996;Bean et al, 2002).…”

“…For example, step-up exercises can be performed: (1) using aerobic (Worrell et al, 1993;Scharff-Olson et al, 1996) or classic 'weightlifting' (Shaw and Snow, 1998;Snow et al, 2000) techniques, (2) using forward step-up (FS) or lateral step-up (LS) motions (Worrell et al, 1993;Scharff-Olson et al, 1996;Cook et al, 1992), and (3) using a step-bench (Shaw and Snow, 1998;Snow et al, 2000) or a flight of stairs (Cress et al, 1996;Bean et al, 2002). In regards to exercise participation and equipment accessibility, however, bench step exercise is likely to be more applicable for older adults than stair-climbing exercise because many elders do not have a flight of stairs within their home.…”