Low load, high repetition resistance training program increases bone mineral density in untrained adults.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 26364686 · doi:10.23736/S0022-4707.16.05697-8
What was done
Twenty sedentary, healthy adults (6 men, 14 women, aged 28–63 years) completed a 27-week group exercise study. Participants were randomized to either full-body, low-load, high-repetition weight training (S-WEIGHT) or core-focused fusion classes (S-CORE). Both groups also performed indoor cycling classes. Following a 3-week familiarization phase, participants completed 12 weeks of 5 classes/week (3 cycling, 2 strength) and a subsequent 12 weeks of 6 classes/week (3 cycling, 3 strength). Bone mineral density (BMD) was assessed via iDXA at week 3 (baseline) and week 28.
What was found
Compared to baseline, BMD in the S-WEIGHT group significantly increased in the arms (+4%, P < 0.001), legs (+8%, P < 0.01), pelvis (+6%, P < 0.01), and lumbar spine (+4%, P < 0.05). The S-CORE group exhibited no statistically significant changes in BMD at any measured site.
Why it matters
High-load lifting increases bone mass but can be difficult for untrained or older adults to sustain; these findings suggest low-load, high-repetition resistance training may offer an effective alternative for improving bone mineral density.
Limits
The study sample was very small (total n=20 split between two arms) with a wide age range (28 to 63 years) and predominantly female participants (70%). The abstract does not report dietary control, calcium/vitamin D intake, menopausal status, or long-term retention of bone gains.
Cited by
- contradicts Resistance training with moderate loads in the 8 to 12 repetition range provides greater bone mineral density benefits than performing high repetitions with light weights.