title: Effect of high-impact aerobics and strength training on BMD in young women aged 20-35 years.
abstract: To evaluate the effects of a 12-month exercise intervention using either high-impact step aerobic exercise or moderate-intensity strength training on areal bone mineral density (aBMD) we studied 51 untrained women, aged 20-35 years, for this study. Whole body and heel and wrist aBMD were measured by dual-energy X-ray absorptiometry (DXA, Hologic or PIXI Lunar). Subjects were randomly assigned to: impact-loaded step aerobic exercise (SA, n=15), moderate-intensity lower body strength training (ST, n=16) or non-exercise control (CON, n=20). Data analysis only included those who completed 95% of each training routine and attended at least 80% of all sessions. Group differences in aBMD, leg press strength and urinary cross-link deoxypridinoline (μDPD) were analysed using analysis of variance. After a 12-month intervention, the SA elicited an increase in aBMD of the heel (4.4%, p<0.05) and leg press strength (15%, p<0.05), relative to baseline. Meanwhile, the ST showed an increase in leg press strength (48%, p<0.05) with no significant increase in aBMD at any measured site. Similar and unchanged μDPD was observed in all 3 groups at baseline, 6 and 12 months. In conclusion, a 12-month high-impact step aerobic exercise resulted in a significant increase in the heel aBMD in untrained young women, who complied with the exercise regimen. A moderate intensity strength training intervention of similar duration had no effect on aBMD although leg strength increased significantly.
authors.affiliation: California State Polytechnic University Pomona, United States. mtcliang@csupomona.edu
authors.forename: M T C
authors.initials: MT
authors.lastname: Liang
authors.forename: W
authors.initials: W
authors.lastname: Braun
authors.forename: S L
authors.initials: SL
authors.lastname: Bassin
authors.forename: D
authors.initials: D
authors.lastname: Dutto
authors.forename: A
authors.initials: A
authors.lastname: Pontello
authors.forename: N D
authors.initials: ND
authors.lastname: Wong
authors.forename: T W
authors.initials: TW
authors.lastname: Spalding
authors.forename: S B
authors.initials: SB
authors.lastname: Arnaud
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000596:Amino Acids / Q000652:urine; D015415:Biomarkers / Q000652:urine; D001827:Body Height; D001835:Body Weight; D015519:Bone Density / Q000502:physiology*; D002136:Calcium, Dietary / Q000008:administration & dosage; D003404:Creatinine / Q000652:urine; D015930:Diet Records; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D053580:Muscle Strength / Q000502:physiology; D010809:Physical Fitness; D017697:Premenopause; D055070:Resistance Training; D016474:Weight-Bearing / Q000502:physiology; D055815:Young Adult
chemical_list: D000596:Amino Acids; D015415:Biomarkers; D002136:Calcium, Dietary; C036020:deoxypyridinoline; D003404:Creatinine