骨粗鬆症と身体活動のジャーナル
オープンアクセス

概要

Marked Improvement in Physical Function through Gains in Muscle Strength and Thigh Muscle Size after Heavy-Load Strength Training in Women with Established Postmenopausal Osteoporosis

Raastad T, Kvernvik KJ, Johansen MA,Running A, Dullerud R, Kvamme N, Solberg P and Gautvik KM

Purpose: To test feasibility and effectiveness of a well-controlled strength training program in postmenopausal women with osteoporosis.

Methods: A total of 22 women (56-80 years) with established osteoporosis were recruited. Strength training was conducted three times per week for 15 weeks. After an initial familiarization period of 2 weeks, strength training was performed with one to three 4-12 repetition maximum (RM) sets in squats, standing calf rise, leg press, rowing, chest press and shoulder press. Strength was measured as 1 RM in chest press, shoulder press and knee extension. Physical function was measured through five different activities (stair climb with and without load, chair raise, timed up and go and 6 minute walk test). Cross sectional area (CSA) of thigh muscles was measured with CT. Bone mineral density and body composition was measured by dual-energy X-ray absorptiometry (DXA).

Results: Strength increased by 33 ± 4% (mean ± SD) in chest press, 44 ± 8% in shoulder press and 36 ± 4% in knee extension (p<0.01). CSA of knee extensors increased by 8 ± 1% (p<0.01). Performance in stair climb and in chair rise was improved by 7 ± 3% and 7 ± 2%, respectively (p<0.05). There were no significant changes in bone mineral density or lean body mass, but fat mass was reduced by 1.0 kg (p<0.01). There were no significant changes in wellbeing indices, but exercise motivation and perceived competence were improved (ES = 0.54 ± 0.45 and 0.55 ± 0.38, respectively).

Conclusions: Strength training in postmenopausal women with established osteoporosis was feasible and effective in improving muscle mass and strength. Importantly, the increased muscle strength was translated to improved function in activities of daily living and exercise competence and motivation was improved.