Effects Of Weight-bearing Exercise Research Articles

Dance-based exercise program in rheumatoid arthritis. Feasibility in individuals with American College of Rheumatology functional class III disease.

Many studies have demonstrated that aerobic exercise training is beneficial to prevent physical deconditioning in persons with rheumatoid arthritis (RA) without inducing adverse effects on individual's joints and general health. After significant results in individuals with RA (Functional Class I and II), the present study was conducted to demonstrate the feasibility of a modified dance-based exercise program to improve the physical fitness and psychological state of persons with RA (Class III). Ten (10) female subjects (mean age, 54 +/- 10 years) participated in an eight-week exercise program (twice weekly). Health status, use of medication, joint pain and swelling, cardiorespiratory fitness, activity of daily living, and psychological state were assessed before and after the training program. A high level of participation has been maintained by the participants (mean = 14.8/16 sessions). Most of them were able to perform a maximal exercise test on treadmill and reached 90% of the predicted heart rate at maximal exercise. No significant gain in aerobic power was observed for the group as a whole, but four subjects showed improvements of between 10% and 20% of their cardiorespiratory fitness. Positive changes in depression, anxiety, fatigue, and tension were observed after the eight-week exercise program. No deleterious effect on the health status was observed. These findings provide some evidences as to the feasibility of submitting individuals with RA to a modified dance-exercise program. Further studies, however, are required to determine the long-term effect of weight-bearing exercise on the health status of individuals with RA.

Regular exercise dissociates fat mass and bone density in premenopausal women.

Body weight is one of the principal determinants of bone density and fracture frequency, but there is significant disagreement in the literature regarding the relative contributions of the lean and fat components of body weight to this relationship. As previous studies have not considered the possible role of exercise in soft tissue-bone density interrelationships, we measured areal bone mineral density (BMD), fat mass, and lean mass in eumenorrheic premenopausal women and determined whether the interrelationships of these variables are influenced by the subject's exercise status. Subjects with mean activity levels of more than 140 kilojoules/kg.day (equivalent to undertaking vigorous physical activity for > 1.5 h/week) were classified as exercisers. In the nonexercising subjects (n = 36; age, 36 +/- 8 yr), BMD was markedly weight dependent (0.45 < r < 0.62), and this was contributed to by both fat and lean tissue. Because this finding may have arisen from the mutual dependence of soft tissue mass and areal BMD on body size, fat and lean masses were reexpressed as a percentage of body weight. The percent fat tended to be positively related to areal BMD (0.23 < r < 0.35), whereas the percent lean was inversely related to this index. A second way of obviating the mutual dependence of soft tissue mass and areal BMD on body size is to derive BMD/height as an index of volumetric bone density. This parameter was only related to lean mass in the femur, whereas the correlations with fat mass were little changed. The percent fat was positively (0.29 < r < 0.43) and the percent lean was negatively (-0.43 < r < -0.29) related to BMD/height throughout the skeleton, including the femur. In the exercising subjects (n = 63; age, 33 +/- 8 yr), fat mass and lean mass were unrelated to BMD/height (r < 0.23). However, the percent lean was positively correlated with BMD and BMD/height in the femoral neck (r = 0.28 and r = 0.31, respectively). It is concluded that bone density is only associated with fat mass in sedentary women. In exercisers, femoral neck density is related to lean mass, possibly through the effects of weight-bearing exercise on both of these variables.

The Functional Fitness Assessment Battery: Reliability and Validity Data for Elderly Women

A battery of field tests was recently developed to assess five fitness parameters in elderly persons. The present study examined the test-retest reliability of each item in the battery and tested the validity of the cardiorespiratory endurance item. Reliability and validity data were obtained from two convenience samples. The 29 subjects in the reliability study were community-living women enrolled in seniors’ exercise classes. The validity of the cardiorespiratory endurance item was tested by comparing it with maximal work capacity on a treadmill test. The 52 women in that part of the study were all participants in a study to assess the effect of weight-bearing exercises on women with low bone mass. Both samples were combined for a principal component analysis. Low reproducibility was observed for coordination (0.54) and strength/endurance (0.56). After slightly modifying the test protocol for these two items, reproducibility reached 84 and 94%, respectively. The correlation between the cardiorespiratory endurance score and maximal work capacity was −0.65, while that between the composite score and maximal work capacity was −0.64. Given these minor modifications, then, the Functional Fitness Assessment battery is a reliable and valid tool for assessing functional fitness in elderly women.

Weight training decreases vertebral bone density in premenopausal women

The effect of exercise on bone mass is unclear. To determine the skeletal effect of weight-bearing exercise in premenopausal women, we prospectively evaluated the effects of a weight-training program on lumbar spine bone mass in 10 women (mean +/- SEM, 36.2 +/- 1.3 yr) and compared the results with those in 7 sedentary women (40.4 +/- 1.6 yr). None of the women had previously participated in a weight-training program, and all ingested a 500-mg calcium supplement each day throughout the study. Axial loading and balance of large muscle groups were emphasized. Individual strength increased by 57 +/- 8% over 9 months. Despite the increase in muscle strength, lumbar spine bone density in the exercising women decreased by 2.90% at 4.5 months and 3.96% at 9 months (P = 0.01). In contrast, there was no change in lumbar density in the controls over the 9-month period. We conclude that short term weight training at this frequency and intensity decreases vertebral bone mass in premenopausal women.