Why weight-bearing exercise is crucial for building bones

Our bones are a living tissue and like any living tissue, they need and require certain factors to keep them healthy.  Drinking milk is a mainstay and will continue to be an important part of making bones strong.  However there is more to bone health than pouring a glass of milk – weight-bearing exercise.

In order for bones to be stimulated to grow and maintain integrity, they require stress.  If you only drink milk or eat other calcium rich foods without exercise, you won’t get the results of optimal bone mass.   It’s the same thing as when you are trying to build strong muscles – if you only eat extra protein without exercise, you won’t reach maximum muscle mass.

The more you incorporate weight- bearing exercise in your fitness routine, the greater chance you will have a higher peak bone mass contributing to overall bone health. 

A 2016 position statement from the National Osteoporosis Foundation deemed the lifestyle factors of calcium intake and exercise deserved a grade A for conclusively positively affecting peak bone mass in adults.  Other lifestyle factors such as vitamin D and protein also positively associated affecting bone mass, received a lower grade as they appeared to not have as a significant impact on bone health as calcium and exercise.

Why is weight-bearing exercise important for bone health?

Bone health and strength are positively influenced by weight-bearing exercise for several reasons:

·      When there is stress on the bone, such as from jumping rope or fast walking, this stimulates calcium uptake leading to new bone formation particularly in children.

·      Participating in exercise promotes stronger muscles and enhances coordination and balance, reducing the risk of falling and breaking a bone. 

·      High-impact exercise has a site-specific effect on bones so that the area influenced by this will have the most benefit.

·      All ages can achieve benefits to their bones with weight-bearing exercise. In both premenopausal and postmenopausal women, both at risk for osteoporosis will experience increases in bone density from weight-bearing exercise. 

Types of weight-bearing exercise

The key concept to bear in mind is not all exercise will have a positive impact on our bones.  For example, swimming or bicycling are excellent for heart health but do little for bone health as they are not weight-bearing.   Weight-bearing exercise creates stress on the bones needed to stimulate mineral uptake of calcium.  This is crucial for adolescents, the time of life when increases in bone mass are at its peak.  A teenager who drinks his milk and engages in some form of regular weight-bearing exercise will have a greater optimal bone mineral content than another teenager who doesn’t do this.

The National Osteoporosis Foundation recommends adults engage in weight-bearing exercise for 30 minutes most days of the week.  Strength-building exercises should also be part of a fitness routine and performed two to three days a week.  To enhance balance and posture, it is recommended to do functional exercises such as yoga or Pilates every day or at least most days of the week.

Here are examples of each:

High-Impact weight-bearing exercises – do 30 minutes most days of the week

·      Jumping rope

·      Hiking

·      Dancing

·      Jogging or running

·      Climbing stairs

·      Playing tennis

·      High-impact aerobics

Low-Impact weight-bearing exercises – do 30 minutes most days of the week

·      Fast walking

·      Using a stair-step machine

·      Using elliptical machines

·      Low-impact aerobics

Strength-building exercises – do at least twice a week

·      Lifting weights

·      Using elastic bands

·      Using weight machines

·      Body weight exercises such as pushups or pullups

Exercises for balance, stretching and posture – do every day or as often as possible

·      Yoga

·      Pilates

·      Tai chi

·      Basic stretching

·      Barre exercises