Tracking of physical fitness components in boys and girls from the second to sixth grades.

The purpose of this study was to examine the tracking of field-assessed fitness components in boys and girls from the second to sixth grades. A total of 857 children (448 boys and 409 girls) from 11 urban schools were tested in grade 2; 565 children (297 boys and 268 girls) were tested again in grade 6. Only subjects who had completed all fitness tests on the two occasions were included in the analysis (n = 319: 203 boys and 116 girls). Fitness tests included a 600-m run, a flying-start sprint, the standing long jump, and a medicine ball throw. Additionally, subjects performed a skill task that involved slalom dribbling of a basketball. Baseline scores in grade 2 were correlated (Spearman Rank Order) with scores attained in grade 6. Boys had significantly (P < 0.05) better scores in all fitness tests compared with girls in both grades. Tracking of fitness components over the 4-year period in both sexes varied between 0.36 and 0.66. Tracking was consistently lower in girls than in boys, perhaps reflecting their earlier maturation.

Dynamic bone loading exercises for postmenopausal women: effect on the density of the distal radius.

A set of dynamic bone loading exercises for the distal forearm, designed for high rates of loading, within physiologic range, and diversity of strain regime, was applied to a group of postmenopausal osteoporotic women. The effect of five months of three weekly sessions, 50 minutes each, on the bone status was studied by measuring the bone density at the distal radius by the Compton scattering technique. A group of 14 women who participated in the program and an inactive group of 26 women were examined one year prior to the study, at its beginning and at its end. During the year preceding the exercise program the mean bone density in both groups decreased significantly. During the exercise period the bone density of the exercise group increased by 3.8% while that of the control group continued to decline. This study demonstrates that an appropriate physical activity regime may be effective as a prophylactic treatment for postmenopausal bone loss.

Increased trabecular bone density due to bone-loading exercises in postmenopausal osteoporotic women.

A program of diverse and dynamic loading exercises of the distal forearm, a common site of osteoporotic fractures, was applied three times a week for 5 months to 14 postmenopausal osteoporotic women. Two parameters were used to assess the effect of the exercises on bone mass. The mass density of bone (g/cm3) was measured by the Compton scattering technique. The bone mineral content (g/cm2) was measured by single photon absorptiometry. Both measurements were taken at the same location in the distal radius 1 year prior to the exercise period, at its beginning, and at its end, in both the exercised group and a matched control group of 26 osteoporotic women. During the exercise period the mean bone density decreased by 1.9% in the control group whereas it increased by 3.8% in the exercise group. The bone mineral content results did not demonstrate any significant trend over the whole period of the study. It is concluded that the trabecular bone tissue in the distal radius of postmenopausal osteoporotic women responds favorably to dynamic and diverse bone stressing exercises even in the seventh decade of life.