Bone density in elite judoists and effects of weight cycling on bone metabolic balance

Med Sci Sports Exerc. 2006 Apr;38(4):694-700. doi: 10.1249/01.mss.0000210207.55941.fb.


Purpose: Weight cycling has been shown to exert negative effects on bone metabolism and bone mass, whereas weight-bearing activity is positively associated with bone mineral density (BMD). Bone health in judoists and effects of weight cycling on bone metabolism have not previously been investigated. To examine potential disrupter and stimulators of bone integrity, this study analyzed bone parameters at baseline and the effects of the first weight cycle of the season on bone metabolic status in 48 male and female elite judoists.

Methods: Body composition and lumbar, femoral, and total body BMD were evaluated by dual-energy x-ray absorptiometry. Cortisol, osteocalcin, C-terminal telopeptide of type I collagen (CTx), and bone uncoupling index (UI) were measured in judoists at normal body weight, after weight reduction, and after regaining weight. As a comparison, a control group of moderately active students was included at baseline. Training, menstrual status, and calcium intake were assessed by questionnaires.

Results: EUweighted judoists displayed high BMD and an increased rate of bone formation. Precompetitive weight loss averaged 4 +/- 0.3% of body weight and induced an acute rise in cortisol (81%, P < 0.05) and CTx (33%, P < 0.0001), with a metabolic imbalance in favor of bone resorption. A 4 +/- 0.5% weight regain restored a positive UI in favor of bone formation. Metabolic responses were not dependent on gender. BMD was unaltered by weight cycling.

Conclusions: Increased bone formation rate pertaining to judo athletes lent protection from alterations in bone metabolic balance associated with weight cycling. This observation suggests that powerful osteogenic stimuli provided by judo's unique biomechanical environment may help prevent bone loss associated with weight loss.

MeSH terms

  • Absorptiometry, Photon
  • Adult
  • Analysis of Variance
  • Body Composition
  • Bone Density / physiology*
  • Bone and Bones / metabolism*
  • Chi-Square Distribution
  • Collagen Type I / metabolism
  • Female
  • Humans
  • Hydrocortisone / blood
  • Longitudinal Studies
  • Male
  • Martial Arts / physiology*
  • Osteocalcin / metabolism
  • Surveys and Questionnaires
  • Weight Lifting / physiology*
  • Weight Loss


  • Collagen Type I
  • Osteocalcin
  • Hydrocortisone