**6. Summary**

Endurance running is a popular aerobic activity and typical training type. However, related human studies reveal no significant benefits to bone health based on densitometric measurement of bone mineral. On the other hand, animal studies apparently indicate that ERT enhances biomaterial of bone tissue in a size-independent way. The effects of endurance running on the organic bone matrix or other parameters, as well as their relationship to mechanical properties of bone tissues, are worthy of further study.

## **7. Acknowledgments**

This study was supported by a grant from the National Science Council: NSC 99-2410-H-006 -114 -MY2. Miss Jae Cody is appreciated for her editorial assistance.
