Bone gained from physical activity and lost through detraining: a longitudinal study in young males

Area of Science:

• Sports Science
• Bone Physiology
• Adolescent Health

Background:

• Bone mineral density (BMD) is crucial for skeletal health, influenced by physical activity.
• Adolescence is a critical period for bone mass accumulation.
• The impact of specific sports training and subsequent detraining on BMD in young males requires further investigation.

Purpose of the Study:

• To examine the longitudinal effects of ice hockey training and detraining on bone mineral density (BMD) in adolescent males.
• To compare BMD changes in weight-bearing and non-weight-bearing bones between athletes and controls.
• To assess the long-term impact of activity cessation on BMD.

Main Methods:

• A longitudinal study involving 43 adolescent ice hockey players and 25 controls.
• Bone mineral density (BMD) measurements using dual-energy X-ray absorptiometry at baseline, 30, and 70 months.
• Tracking BMD changes in arms, humerus, femur, femoral neck, and total hip.

Main Results:

• Ice hockey players showed significantly greater BMD gains in the femoral neck and arms compared to controls during training.
• Athletes who ceased training experienced significant BMD loss at the femoral neck and hip within 3 years.
• Active athletes maintained higher BMD at the non-dominant humerus and other sites compared to controls throughout the study.
• No significant differences in bone size (bone area) were observed between groups.

Conclusions:

• Ice hockey training promotes continuous bone mineral density (BMD) accumulation in adolescent males post-puberty.
• Cessation of intense physical activity leads to significant BMD loss, particularly at weight-bearing skeletal sites.
• The observed effects are specific to bone density, not bone size, highlighting the adaptive response to mechanical loading.