Strength training for obesity prevention in midlife women

Abstract

OBJECTIVE:The primary goal of this study was to assess whether increases in fat-free mass (FFM) and decreases in total and percentage fat mass from 15 weeks of twice weekly supervised strength training would be maintained over 6 months of unsupervised exercise in a randomized controlled trial. DESIGN: In all, 60 women aged 30-50 y, body mass index between 20 and 35 kg/m 2 , were randomized to control or treatment groups. The treatment group performed twice-weekly supervised strength training followed by 6 months of unsupervised training. Measurements at baseline, 15, and 39 weeks included body weight and body composition by dual-energy X-ray absorptiometry. Repeated measures regression was used to assess between-group differences for changes over time. RESULTS: Almost 90% of prescribed exercise sessions were completed. The body composition treatment effects over 15 weeks were largely maintained over 6 months of unsupervised exercise. Over the total 39 weeks of strength training, the treatment group gained +0.89 kg more in FFM, lost À0.98 kg more in fat mass, and lost -1.63% more in percent body fat when compared to the control group. P-values for these between-group differences in 39-week changes were 0.009, 0.06, and 0.006, respectively. Strength training did not result in any significant weight loss or waist circumference attenuation. Adjustment for changes in energy intake and physical activity did not alter these results. CONCLUSIONS: Twice-weekly strength training is behaviorally feasible for busy midlife women and the favorable body composition changes resulting from supervised strength training can be maintained over time. These findings lay the groundwork for determining the long-term health benefits of this behaviorally feasible exercise prescription, potentially including prevention of age-associated fat gains.

Strength Training for Women as a Vehicle for Health Promotion at Work

“…Jakobsen et al were the only authors to report effect sizes for a portion of their results (23). For three publications effect sizes could not even be calculated retrospectively (25,28,30). The effect sizes we calculated are given with the individual results below.…”

“…After elimination of duplicates and scrutiny of study titles and abstracts, 68 articles remained for full-text analysis. Twelve publications fulfilled the selection criteria laid out in Table 1 (19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). The commonest reasons for exclusion were the absence of sex-specific analysis and the lack of muscle strength measurement.…”

Home-Based Resistance Training Is Not Sufficient to Maintain Improved Glycemic Control Following Supervised Training in Older Individuals With Type 2 Diabetes

“…Schmitz et al (13) found that increases in LBM after a 15-week supervised strength-training program in middle-aged women could be maintained over 6 months through an unsupervised program in an exercise facility. In addition, the observation that muscle strength increases from a supervised resistance training program were maintained after 6 months of home-based training is consistent with recent findings in overweight middle-aged women (13). However, the finding that home-based training did not induce further strength gains from those observed during supervised training is most likely due to the reduced training volume during this period.…”

Effects of weight training on quality of life in recent breast cancer survivors

“…20 -23 Second, adherence to exercise interventions is an issue for all populations and we have recently demonstrated the behavioral feasibility of twice-weekly weight training among midlife women who are not cancer survivors. 23 Finally, there is the potential that for breast cancer survivors, weight training might increase a sense of control over their lives during the 'watchful waiting' time frame between the end of active treatment and the 5-year mark postdiagnosis (e.g., psychological empowerment via physical strength increases).…”