[Does exercise improve the skeleton of young women?].
BACKGROUND
High bone mineral density (BMD) at menopause can reduce the risk for osteoporotic fractures later in life, hence it is important to identify factors that can increase or maintain BMD during the premenopausal years. Physical activity is considered a major factor. This review examines how physical activity affects BMD in premenopausal women.


METHODS
The literature was identified on Medline. In addition, relevant books were examined.


RESULTS
Research indicates that weight-bearing exercises that involve high-magnitude loading can maintain or increase BMD in premenopausal women, especially in the loaded bones. Low to moderate intensive training and non-weight bearing exercise show minor or no effect on BMD.


CONCLUSIONS
In every day life, effective physical activity or training to maintain or increase bone mass in young women ought to include short-term high mechanical load, preferably with unusual load distribution, which also is fast and dynamic. Physical activity in young women seems to be an important factor in reducing the risk of osteoporotic fractures later in life.
Torstveit
Monica Klungland
MK
Norges idrettshøgskole, idrettsmedisinsk seksjon Postboks 4014 Ullevål stadion 0806 Oslo. monica.torstveit@nih.no
D000328:Adult; D015519:Bone Density / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D015663:Osteoporosis, Postmenopausal / Q000517:prevention & control; D010809:Physical Fitness / Q000502:physiology; D017697:Premenopause / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology*