The most consistent results were that long-term physical activity is related to postponed disability and independent living in the oldest-old subjects. Even in individuals with chronic disease, systematic participation in physical activities enhances physical function.

Training focusing on strength, balance, and endurance can enhance physical performance for up to 24 months in community-dwelling older adults. These findings did not translate to improved fall-related psychological outcomes or reduced incidence of falls. This demonstrates the need for a different approach (e.g., regarding intervention dose and components) to gain intervention benefits in the multiple domains that contribute to independence and well-being in older adults.

No abstract

The SRT, DRT, and MT of older men (OA) who have experienced a life style of chronic physical activity were compared to those of nonactive men of similar age (ONA), and also to active (YA) and nonactive young men (YNA). Although activity level and age were significant factors, most of the activity level-by-age interaction in all but DRT was attributed to the slower performance of the ONAs. At least in this study, a life style of physical activity appeared to play a more dominant role in determining SRT, DRT, and MT than age. The hypothesis that most of the slowing of responses in the aged is attributable to CNS processing rather than MT decrements is repudiated, since MT results paralleled those of SRT and DRT.

The robustness of a relationship among physical fitness, psychomotor speed, and aging is discussed by reviewing the descriptive and correlational evidence provided by studies from several different research areas. These areas are those that relate psychomotor speed to (a) athletic status, (b) physical fitness status, (c) physical conditioning training programs, (d) hyperbaric oxygenation treatment, and (e) presence of cardiovascular disease. Several potential physiological mechanisms that might support such a relationship are discussed under the general categories of brain function and cerebral circulation, and the trophic influence of physical activity on the central nervous system.

Background. Previous investigators have reported that maximal power increases during growth and decreases with aging. These age-related differences have been reported to persist even when power is scaled to body mass or muscle size. We hypothesized that age-related differences in maximal power were primarily related to differences in muscle size and fiber-type distribution rather than to age per se.

The latency and consistency of simple reaction time, choice reaction time, and movement time of older men who chronically run or participate in racket sports were compared to those of nonactive men of similar age and also to young men of similar characteristics (young runners, young racketsportsmen, and young nonactive men). The findings of Spirduso's (1975) study, of which this investigation was both a replication and an expansion, that older active men physically reacted to stimuli and moved their forearm over a 20 cm distance as quickly as young sedentary men was reported. The older active men were far superior to older sedentary men in all measures. In addition, the older active group was similar to the groups in terms of group homogeneity and within-subject variability, unlike the older nonactive group, who revealed the commonly reported group heterogeneity and within-subject inconsistency.

The purpose of this investigation was to determine the effects of cycle crank length on maximum cycling power, optimal pedaling rate, and optimal pedal speed, and to determine the optimal crank length to leg length ratio for maximal power production. Trained cyclists (n = 16) performed maximal inertial load cycle ergometry using crank lengths of 120, 145, 170, 195, and 220 mm. Maximum power ranged from a low of 1149 (20) W for the 220-mm cranks to a high of 1194 (21) W for the 145-mm cranks. Power produced with the 145- and 170-mm cranks was significantly (P < 0.05) greater than that produced with the 120- and 220-mm cranks. The optimal pedaling rate decreased significantly with increasing crank length, from 136 rpm for the 120-mm cranks to 110 rpm for the 220-mm cranks. Conversely, optimal pedal speed increased significantly with increasing crank length, from 1.71 m/s for the 120-mm cranks to 2.53 m/s for the 220-mm cranks. The crank length to leg length and crank length to tibia length ratios accounted for 20.5% and 21.1% of the variability in maximum power, respectively. The optimal crank length was 20% of leg length or 41% of tibia length. These data suggest that pedal speed (which constrains muscle shortening velocity) and pedaling rate (which affects muscle excitation state) exert distinct effects that influence muscular power during cycling. Even though maximum cycling power was significantly affected by crank length, use of the standard 170-mm length cranks should not substantially compromise maximum power in most adults.