Certain types of weight-lifting and jumping exercises, when completed for at least 6 months, improve bone density in active, healthy, middle-aged men with low bone mass, according to a study published online ahead of print June 16 in Bone.
“Weight-lifting programs exist to increase muscular strength, but less research has examined what happens to bones during these types of exercises,” said Pam Hinton, PhD, Associate Professor and Director of Nutritional Sciences Graduate Studies in the University of Missouri Department of Nutrition and Exercise Physiology in Columbia, Missouri. “Our study is the first to show that exercise-based interventions work to increase bone density in middle-aged men with low bone mass who are otherwise healthy. These exercises could be prescribed to reverse bone loss associated with aging.”
Pam Hinton, PhD
Dr. Hinton and colleagues studied 38 physically active, middle-aged men with osteopenia of the hip or spine who completed either a weight-lifting program or a jumping program for 1 year. Both programs required participants to complete 60 to 120 minutes of targeted exercise each week. The participants took calcium (1200 mg/day) and vitamin D (10 mcg/day) supplements throughout their training programs. The researchers measured the men’s bone mass at the beginning of the study and again at 6 and 12 months using DXA scans of the whole body, total hip, and lumbar spine.
The investigators found the bone mass of the whole body and lumbar spine significantly increased after 6 months of completing the weight-lifting or jumping programs, and this increase was maintained at 12 months. Hip-bone density only increased among those who completed the weight-lifting program.
Dr. Hinton said the study results do not indicate that all kinds of weight-lifting will help improve bone mass; rather, targeted exercises made the training programs effective.
“Only the bone experiencing the mechanical load is going to get stronger, so we specifically chose exercises that would load the hip and the spine, which is why we had participants do squats, deadlifts, lunges, and the overhead press,” Dr. Hinton said. “Also, the intensity of the loading needs to increase over time to build strength. Both of the training programs gradually increased in intensity, and our participants also had rest weeks. Bones need to rest to continue to maximize the response.”
Throughout their training programs, participants rated pain and fatigue after completing their exercises. The participants reported minimal pain and fatigue, and these ratings decreased over the year. Dr. Hinton said individuals who want to use similar training programs to improve bone density should consider their current activity levels and exercise preferences as well as time and equipment constraints.
“The interventions we studied are effective, safe, and take 60 to 120 minutes per week to complete, which is feasible for most people,” Dr. Hinton said. “Also, the exercises can be done at home and require minimal exercise equipment, which adds to the ease of implementing and continuing these interventions.”