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

Osteoporos Int. 2007 Jun;18(6):789-96. doi: 10.1007/s00198-006-0305-9. Epub 2007 Jan 31.


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.

Publication types

  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Absorptiometry, Photon / methods
  • Adolescent
  • Adult
  • Anthropometry / methods
  • Arm / physiology
  • Body Composition / physiology
  • Bone Density / physiology*
  • Connective Tissue / anatomy & histology*
  • Exercise / physiology*
  • Female
  • Humans
  • Leg / physiology
  • Muscle Strength / physiology*
  • Muscle, Skeletal / physiology*