Osteoporosis International

, Volume 18, Issue 6, pp 789–796

Concentric and eccentric isokinetic resistance training similarly increases muscular strength, fat-free soft tissue mass, and specific bone mineral measurements in young women

Authors

    • Department of Nutritional SciencesThe Pennsylvania State University
  • L. E. Miller
    • Department of Human Nutrition, Foods and Exercise (0430)Virginia Polytechnic Institute and State University
  • D. F. Wootten
    • Department of Human Nutrition, Foods and Exercise (0430)Virginia Polytechnic Institute and State University
  • W. K. Ramp
    • Health Research Group
  • W. G. Herbert
    • Department of Human Nutrition, Foods and Exercise (0430)Virginia Polytechnic Institute and State University
    • Health Research Group
Original Article

DOI: 10.1007/s00198-006-0305-9

Cite this article as:
Nickols-Richardson, S.M., Miller, L.E., Wootten, D.F. et al. Osteoporos Int (2007) 18: 789. doi:10.1007/s00198-006-0305-9

Abstract

Summary

Women participated in 5 months of unilateral concentric (n = 37) or eccentric (n = 33) isokinetic resistance training of the legs and arms. Limb muscular strength increased as did total body, leg, and arm fat-free soft tissue mass, total body BMC, hip BMD, and forearm BMC and BMD. Isokinetic training benefits bone mineral acquisition.

Introduction and hypothesis

Isokinetic resistance training (IRT) is osteogenic; however, it is not known if concentric or eccentric modalities of IRT produce differential effects on bone. We tested our hypothesis that high-load eccentric versus concentric mode of IRT would produce greater increases in muscular strength, fat-free soft tissue mass (FFSTM), bone mineral density (BMD) and content (BMC) in trained legs and arms.

Methods

Participants were randomized to 5 months of concentric (n = 37) or eccentric (n = 33) training. The non-dominant leg and arm were used during training; dominant limbs served as controls. Muscular strength was measured with an isokinetic dynamometer; body composition was measured by dual-energy X-ray absorptiometry.

Results

Muscular strength of the concentrically and eccentrically trained leg (18.6%; 28.9%) and arm (12.5%; 24.6%) significantly increased with training. Gains in total body (TB) BMC (p < 0.05) and, in the trained limbs, total proximal femur BMD (p < 0.05) and total forearm BMD (p < 0.05) and BMC (p < 0.05) occurred in both groups. FFSTM increased for the TB and trained leg and arm (all p < 0.001) in both modes.

Conclusion

Regardless of the mode, high-intensity, slow-velocity IRT increases muscular strength and FFSTM of trained limbs and imparts benefits to TB BMC and site-specific BMD and BMC in young women.

Keywords

Bone densitometryBone mineralMechanical loadingMuscular strengthWomen

Copyright information

© International Osteoporosis Foundation and National Osteoporosis Foundation 2007