Resistance Training over 2 Years Increases Bone Mass in Calcium-Replete Postmenopausal Women

Abstract

Understanding the stress/strain relationship between exercise and bone is critical to understanding the potential benefit of exercise in preventing postmenopausal bone loss. This study examined the effect of a 2-year exercise intervention and calcium supplementation (600 mg) on bone mineral density (BMD) in 126 postmenopausal women (mean age, 60 ؎ 5 years). Assignment was by block randomization to one of three groups: strength (S), fitness (F), or nonexercise control (C). The two exercise groups completed three sets of the same nine exercises, three times a week. The S group increased the loading, while the F group had additional stationary bicycle riding with minimal increase in loading. Retention at 2 years was 71% (59% in the S group, 69% in the F group, and 83% in the C group), while the exercise compliance did not differ between the exercise groups (S group, 74 ؎ 13%; F group, 77 ؎ 14%). BMD was measured at the hip, lumbar spine, and forearm sites every 6 months using a Hologic 4500. Whole body BMD also was measured every 6 months on a Hologic 2000. There was no difference between the groups at the forearm, lumbar spine, or whole body sites. There was a significant effect of the strength program at the total (0.9 ؎ 2.6%; p < 0.05) and intertrochanter hip site (1.1 ؎ 3.0%; p < 0.01). There was a significant time and group interaction (p < 0.05) at the intertrochanter site by repeated measures. This study shows the effectiveness of a progressive strength program in increasing bone density at the clinically important hip site. We concluded that a strength program could be recommended as an adjunct lifestyle approach to osteoporosis treatment or used in combination with other therapies. (J Bone Miner Res 2001;16:175-181)

Efeitos da atividade física na densidade mineral óssea e na remodelação do tecido ósseo

“…Among these studies, a few use the strength training, trying to increase the BMD in individuals submitted to that type of physical activity (7,13,14,17) . In general, the same studies have shown positive results related to the BMD (8,15,(17)(18)(19)(20)(21)(22)(23) . Nevertheless, despite this possible benefic effect, quite large training volumes may cause a damage on the BMD, and it seems that such damage is closely related to the disturbance in the hormonal homeostasis of the organism (5,6,24) .…”

“…In fact, higher training intensities related to the peak load are generally associated to higher stimuli to the increasing BMD than lower intensities (3,13,17,18,22,35) . Besides, the use of higher training intensities implies in more immediate responses on the BMD (3) .…”

“…The strength training (ST) has been pointed out as one of the physical activities that results in osteogenesis (3,8,18,21,22,(32)(33)(34) . Nevertheless, there are several points to be discussed as to what ST method would be more effective taking into account the exercises, the intensity and the period necessary in order to attain a bone response.…”

Effects of Resistance Training on Bone and Muscle Mass in Older Women: A Review

“…50 Finally, it has been reported that a significant effect of RT in postmenopausal women (mean age, 60 +/-5 years) over 2 years at the clinically important intertrochanter hip site (+1.1%). 46 Remarkably, the maximum change in BMD occurred in the first year of the intervention. There was lative decline in the rate of change during the second year; however, BMD remained more than a 3% difference between the exercise and control group after 2 years.…”

“…Nevertheless, RT is still one of the most recurrent types of exercise applied in order to improve bone mass in elderly individuals; especially in preventing bone loss among postmenopausal women. 21,46 Previous studies have reported that RT is able to prevent bone demineralization in older women. 47,48 For instance, the study by de Matos, et al 48 reported that 12 weeks of weight training, among postmenopausal women with osteoporosis or osteopenia, did not significantly improve BMD (1.17%) at the lumbar spine in the exercise group (n=30).…”