ORIGINAL ARTICLE  BODY COMPOSITION, NUTRITION 

The Journal of Sports Medicine and Physical Fitness 2017 January-February;57(1-2):70-6

DOI: 10.23736/S0022-4707.16.05697-8

Copyright © 2015 EDIZIONI MINERVA MEDICA

language: English

Low load, high repetition resistance training program increases bone mineral density in untrained adults

Bailey A. PETERSEN ¹, Bryce HASTINGS ², Jinger S. GOTTSCHALL ¹ ✉

¹ Department of Kinesiology, The Pennsylvania State University, University Park, State College, PA, USA; ² Les Mills International, Auckland, New Zealand

BACKGROUND: High load, low repetition resistance training increases BMD in untrained adults; however, many older and untrained adults cannot maintain this type of strenuous program. Our goal was to evaluate whether a low load, high repetition resistance training program would increase BMD in untrained adults.
METHODS: Twenty sedentary, but otherwise healthy, adults (6 men and 14 women, age 28-63 yrs) completed a 27-week group exercise program. The participants were randomly assigned to one of two strength groups: one group completed full body, low load, high repetition weight training classes (S-WEIGHT), while the other group completed core focused fusion classes (S-CORE). Both groups also completed indoor cycling classes for cardiovascular conditioning. After a 3-week familiarization period, all participants completed a 12-week block of 5 fitness classes per week (3 cycling + 2 strength) and concluded with another 12-week block of 6 classes per week (3 cycling + 3 strength). We completed iDXA scans at baseline (week 3) and final (week 28).
RESULTS: Compared to baseline, BMD significantly increased for S-WEIGHT in the arms (+4%, P<0.001), legs (+8%, P<0.01), pelvis (+6%, P<0.01) and lumbar spine (+4%, P<0.05), whereas BMD did not significantly change for S-CORE at any site.
CONCLUSIONS: These results suggest that a low load, high repetition resistance training program may be an effective method to improve bone mass in adults.

KEY WORDS: Muscle strength - Osteoporosis - Exercise test - Fitness centers