What are Weight Bearing Exercises?
Weight bearing exercises are exercises that force our bodies to work against gravity. They encompass any exercises that involve using body weight against the ground in an upright position- walking, running, dancing, tennis, climbing stairs and more.
Why are they important?
Weight bearing exercises are “osteogenic”- this means that they help bones to grow, which provides better strength and stability for our bodies. Stronger and healthier bones reduce the risk of developing disease such as osteoporosis, as well as lowering our chance of injuries including fractures and falls.
Weight bearing exercise can improve bone density no matter what age we are, and should be a priority during all stages of life. Bone density varies between genders and cultures however in general we reach peak bone mass, which is maximum bone strength and density, at around 30 years of age. Bone mass then naturally reduces at a very gradual rate. The more we do to help our bones through maintaining a healthy weight, eating a nutritious diet and engaging in regular weight bearing activities, the slower our bones lose density and strength.
Some groups of people are at greater risk of bone disease or injury, and therefore weight bearing exercise is especially important for these people. These include people already diagnosed with conditions such as osteoporosis, people who are overweight or obese, women who have gone through menopause due to hormonal effects on bone, and people with nutritional deficiencies especially calcium, vitamin D and magnesium. It is also significantly beneficial to introduce weight bearing exercise at a young age so that we have the best chance at forming healthy bones during all the structural and functional changes that occur during puberty.
The structure and function musculoskeletal system is influenced by a range of internal and external factors. When we engage in weight bearing exercise, there is a mechanical pressure placed on our bones which causes our osteoblasts and osteoclasts (bone cells) to remodel and regrow themselves. Studies have demonstrated that bone mass adaptation is improved especially at a younger age when people are involved in weight bearing activity. Exercise also helps to prevent falls and fractures by improving muscle strength, coordination and balance.
Weight bearing exercises fall into two main categories: low impact or high impact. Low impact weight bearing exercises include walking, using elliptical training machines or stair-step machines, low impact aerobics, yoga and pilates. High impact weight bearing activities include jogging, running, high impact aerobics, sports such as tennis and basketball, skipping with a rope, hiking and stair climbing.
The science has also shown that certain techniques improve the effectiveness of weight bearing exercise on bone health. For example, short high intensity bursts have been associated with more positive responses in bone strengthening. Resistance training is also useful as it pulls the muscles on the bones and forces them to strengthen. We also need our weight bearing exercise to be optimally challenging, in that it should become harder and more of a challenge over time so that the body is constantly adapting and strengthening over time.
It is important to note that there are non-weight bearing exercises that are beneficial for our health in other ways, even though they are not specifically therapeutic for bones. Swimming and cycling are an example of these types of exercise. Many people enjoy swimming and cycling and they offer a myriad of health and wellness benefits including improved endurance, muscle strength, cardiovascular fitness and weight management. If you already participate in these types of exercise, make sure you are also regularly engaging in weight bearing exercise in order to target bone health as well as your overall health and get the most out of your exercise regime.
As with all exercise programs, it is recommended that you start slowly with weight bearing exercises and build up gradually over time. This depends on your current level of fitness, any pre-existing injuries or medical conditions that may make intense exercise more difficult. It may be beneficial to talk to a health professional such as your chiropractor or exercise physiologist to work out which exercises will be the safest and most effective for you, and to put a plan in place to build on these and improve your health.
Optimally we should be aiming for at least 30 minutes of physical movement each day.