Physical activity is presented as the only known intervention that can potentially increase bone mass and strength in the early years of life and reduce the risk of falling in older populations; according to a new Position Stand from the American College of Sports Medicine (ACSM).
The official ACSM pronouncement, published in the November issue of Medicine & Science in Sports & Exercise®, encourages the adoption of specific exercise prescriptions designed for various ages to best capitalize on the chances to accrue and preserve bone throughout the various stages of life.
The paper cites worldwide predictions that the number of hip fractures will double by the year 2025, with a mortality rate of 15 to 20 percent within the first year following such a fracture for elderly individuals, as reasons to encourage a better understanding of the types, durations and frequencies of physical activities that help build and maintain bone.
These include high-intensity, high-impact activities for children to build bone and moderate-to-high intensity weight-bearing activities for adults to maintain bone mass.
“As we live longer lives, we increase our chances of suffering from debilitating falls and fractures,’ said Wendy M. Kohrt, Ph.D., FACSM, lead author. ‘Children and adults need to understand and perform the right kinds of physical activities that promote bone health to prevent these problems.”
For adults, experts have established these recommendations to help preserve bone:
- Mode – weight-bearing endurance activities such as tennis and jogging, activities that involve jumping, and resistance exercise (weight lifting).
- Intensity – moderate to high.
- Frequency – weight-bearing activities 3 to 5 times per week, resistance exercise 2 to 3 times per week.
- Duration – 30 to 60 minutes a day combined.
For children, especially in the years surrounding the onset of puberty, experts recommend the following activities to help build bone:
- Mode – impact activities such as gymnastics and jumping activities combined with moderate resistance training.
- Intensity – high, but with appropriate weights for resistance training (no more than 60 percent of the maximum amount a person can lift one time).
- Frequency – at least three days per week.
- Duration – 10 to 20 minutes with multiple sessions within the same day potentially being more effective.
“Recently, science has indicated that exercise can increase bone mass in children if they engage in these exercises,’ said Kohrt. ‘This has been a very exciting and promising area of discovery.”
The Position Stand also explicitly mentions the importance of bone health for men, noting that the predicted increase in osteoporotic falls and fractures in men in the coming decades is even greater than in women. The authors also encourage weight-bearing physical activities for even the most frail and elderly, provided they can still perform them safely.