Building Strong Bones for Life: Why Young Athletes Should Train in Multiple Sports

For years, I coached high-school rowing, a sport notorious for attracting the hyper-focused and hyper-elite. This meant parents were obsessed with their children's performance and a frequent question I got was “what should my child be doing during the off-season to get better at rowing?” My answer often surprised them: “Have them play a different sport.” Many thought it was counterintuitive to step away from rowing to get better at it, but cross-training not only helps maintain a young athlete’s interest in their primary sport, it actually benefits their long-term physical development—especially when it comes to bone health.

Why Cross-Training Matters for Bone Health

The bones in our bodies are constantly changing, breaking down and building back up in response to the forces we place on them. During adolescence, when growth plates are still open, bones have an incredible capacity to grow and adapt. But once those growth plates fuse, that window of opportunity narrows. Adolescence is, therefore, a critical time to encourage bony development through activities that stimulate growth and density.

The Role of Multi-Planar Movements

One of the keys to building strong bones is the need to apply forces from various directions. Bones respond best to load-bearing activities that challenge them in multiple planes, which means varying the type of physical activities we’re exposed to. While running provides some benefit, it primarily strengthens bone along a single plane—the one in which the runner is moving. In contrast, sports that involve jumping, cutting, or changing direction quickly—like soccer, basketball, or gymnastics—apply forces in many directions, which leads to more robust bone development.

Weight-bearing sports are particularly beneficial. For example:

• Gymnastics: The repeated loading from tumbling and vaulting builds bone density.

• Soccer: The frequent changes in direction, acceleration, and deceleration place high loads on bones, which encourages growth and strengthening.

• Basketball and Dance: Both involve multidirectional movement and jumping, promoting bone density in a way that endurance sports like running or cycling do not.

• Other Field or Court Sports: Sports like field hockey, lacrosse, handball, and volleyball require similar demands in terms of jumping and change in direction.

• Weight lifting: The demand on bones under heavy loads is a great way to support your primary sport while also building bone density. Weight lifting is safe for adolescents, though they should do it under supervision. 

When Sports Don’t Support Bone Health

Certain sports are less effective at promoting bone health, particularly those that involve minimal weight-bearing or repetitive single-plane movement. Swimming, while excellent for cardiovascular fitness, is a low-impact sport that places minimal forces on bones, which limits its benefit for bone density. Similarly, cycling provides aerobic benefits but doesn’t engage the bones in the same way, as it is non-weight bearing.

This is where variety becomes essential: by adding activities that involve impact, weight-bearing, and direction changes, we can help kids build the strong bones they need for a lifetime of health.

Making the Most of Youth for Future Health

With this in mind, here are some practical steps to help young athletes make the most of this period of bone growth:

1. Encourage Daily Activity with Intensity: Have kids engage in physical activity daily, ideally including running, jumping, or weight-bearing exercises.

2. Provide Cross-Training Opportunities: Offer options outside of a single sport to encourage the body to experience different forces in various planes. Off-seasons are perfect for branching out—try basketball, gymnastics, or even martial arts to add variety.

3. Monitor Nutrition: Ensure that calcium intake is adequate through a balanced diet. This mineral is crucial for bone health, especially during times of growth.

4. Get Enough Vitamin D: Sunlight is a natural source of Vitamin D, which is essential for calcium absorption. Make sure kids are spending time outdoors (safely and with sun protection) to support their body’s ability to produce Vitamin D.

Investing in bone health through multi-sport training will pay dividends long after their teenage years. By helping young athletes develop a love for movement in many forms, we’re setting them up for a lifetime of strong, resilient bones and all the health benefits that come with them.

References:

"Adolescents who participate in a variety of sports and activities that involve multiple types of physical demands—such as jumping, running, and resistance training—are more likely to develop greater bone density and strength" (Tenforde, A. S., et al., Clinical Journal of Sport Medicine, 2018).

Varied movement patterns and loading directions are shown to stimulate bone density, particularly during adolescence when bones are most responsive to mechanical loading (McKay, H. A., et al., Exercise and Sport Sciences Reviews, 2000).

Sports like soccer, gymnastics, and basketball, which incorporate multi-directional forces and impact, have been found to significantly benefit bone density in young athletes (Faulkner, R. A., et al., Bone, 2006).

Weight-bearing exercises apply mechanical stress that triggers the body’s adaptive response in bones, encouraging greater density (Nikander, R., et al., Journal of Bone and Mineral Research, 2010).

Studies highlight that non-weight-bearing sports like swimming and cycling, while beneficial for cardiovascular fitness, do not yield the same bone density benefits as weight-bearing sports. Swimming, in particular, ranks low in terms of stimulating bone health (Gomez-Bruton, A., et al., Sports Medicine, 2013).

Adequate calcium intake, alongside sufficient vitamin D levels, is crucial for young athletes to support bone growth, especially in conjunction with physical activity (Heaney, R. P., et al., Osteoporosis International, 2000).