Related Experiment Videos
A histomorphometric study of cortical bone activity during increased weight-bearing exercise
D M Raab1, T D Crenshaw, D B Kimmel
1Biogerontology Laboratory, University of Wisconsin, Madison.
Summary
Weight-bearing exercise increased bone formation rates in swine, specifically at the periosteal and intracortical surfaces. This study shows exercise stimulates osteoblast activation without altering bone size or mineral content.
Area of Science:
- Bone Biology
- Exercise Physiology
- Skeletal Remodeling
Background:
- Cortical bone's response to mechanical loading is crucial for skeletal health.
- Understanding exercise-induced bone formation is key for preventing bone loss.
Purpose of the Study:
- To quantify the effects of weight-bearing exercise on cortical bone parameters in adult swine.
- To investigate changes in bone size, mineral content, and formation rates.
Main Methods:
- Adult sows were assigned to sedentary control or treadmill training groups for 20 weeks.
- Bone histomorphometry was used to measure periosteal, endosteal, and osteonal bone formation.
- Measurements included bone length, area, fat-free dry weight, and mineral apposition rate (MAR).
Main Results:
- Exercise did not significantly alter bone length, area, or fat-free dry weight.
- Periosteal formation surface and MAR increased in trained swine compared to controls.
- Osteonal MAR was also higher in the trained group, indicating increased intracortical bone formation.
Conclusions:
- A 20-week treadmill exercise program stimulated periosteal and intracortical bone formation in sedentary adult swine.
- The primary effect of exercise was osteoblast activation, not changes in overall bone size or mass.
- Exercise intensity may need to be higher to induce significant changes in gross bone measures.