Effect of short-term upper-body resistance training on muscular strength, bone metabolic markers, and BMD in premenopausal women

Abstract

Michael TC Liang,1 Lorena Quezada,1 WY Jamie Lau,1 Bulent Sokmen,2 Thomas W Spalding11Department of Kinesiology and Health Promotion, California State Polytechnic University, Pomona, CA, USA; 2Department of Kinesiology, Sonoma State University, Rohnert Park, CA, USAAbstract: To examine the effect of a 10-week upper-body resistance training program on bone turnover markers and site-specific bone mineral density (BMD) in the wrist and distal half of the ulna and radius in untrained and healthy young premenopausal women.Methods: Twenty-two subjects (aged 22.1 ± 1.8 years) were randomly assigned to a resistance training (n = 12) or no training control (n = 10) group. The following outcome variables were measured before and after 10 weeks of resistance training: (1) bone formation biomarker osteocalcin, and bone resorption biomarker tartrate-resistant acid phosphatase isoform 5b; (2) BMD in the wrist and distal half of the ulna and radius; (3) isokinetic strength of the elbow and knee extensors and flexors; (4) dynamic strength of the arm extensors and flexors; and (5) maximum number of push-ups.Results: The 10-week upper body resistance training intervention resulted in improved strength performance in push-ups (resistance training versus control: P < 0.05), chest presses (P < 0.05), and pulldowns (P < 0.05). However, there was no improvement in the BMD of the wrist (P > 0.05), BMD of the distal half of the ulna and radius (P > 0.05), and metabolic biomarkers osteocalcin (P > 0.05) and tartrate-resistant acid phosphatase isoform 5b (P > 0.05), except for the osteocalcin/tartrate-resistant acid phosphatase isoform 5b ratio. Also, no improvement in the resistance training group was observed for isokinetic strength of the knee and elbow flexion/extension.Conclusion: Upper-body muscular strength performance, but not bone metabolic markers and BMD of the wrist, can be improved with a 10-week upper body resistance training program of the nonweight-bearing limbs in untrained young premenopausal women.Keywords: osteocalcin, TRACP5b, wrist and heel mineral density, isokinetic strength, dynamic strength training