title: Exercise and bone mineral density in men: a meta-analysis of randomized controlled trials.
abstract: OBJECTIVE
  Use the meta-analytic approach to examine the effects of ground and/or joint reaction force exercise on femoral neck (FN) and lumbar spine (LS) bone mineral density (BMD) in men.
  
  
  METHODS
  Randomized controlled exercise trials ≥ 24 weeks were included. Standardized effect sizes (g) were calculated and pooled using random-effects models, z-score alpha values and 95% confidence intervals (CI). Heterogeneity was examined using Q and I(2). Statistical significance was set at a two-tailed alpha value (p) of ≤ 0.05 and a trend at >0.05 to ≤ 0.10.
  
  
  RESULTS
  A moderate and statistically significant improvement was found at the FN (3 g's, 187 participants, g=0.583, 95% CI=0.031, 1.135, p=0.04, Q=5.6, p=0.06, I(2)=64%) while a small trend was observed at the LS (5 g's, 275 participants, g=0.190, 95% CI=-0.036, 0.416, p=0.10, Q=3.0, p=0.55, I(2)=0%). Results were sensitive to influence analysis as well as collapsing multiple groups from the same studies so that only one g represented each study.
  
  
  CONCLUSIONS
  There is currently insufficient evidence to recommend ground and/or joint reaction force exercise for improving and/or maintaining FN and LS BMD in men. Additional well-designed randomized controlled trials are needed before any final recommendations can be formulated.
authors.affiliation: School of Public Health, Department of Biostatistics, Robert C. Byrd Health Sciences Center, West Virginia University, PO Box 9190, Morgantown, WV 26506-9190, USA. gkelley@hsc.wvu.edu
authors.forename: G A
authors.initials: GA
authors.lastname: Kelley
authors.forename: K S
authors.initials: KS
authors.lastname: Kelley
authors.forename: W M
authors.initials: WM
authors.lastname: Kohrt
mesh_terms: D000328:Adult; D000368:Aged; D015519:Bone Density; D015444:Exercise; D005272:Femur Neck; D006615:Hip; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic