21 Aug Exercise, Bone Health and Osteoporosis
WHAT IS OSTEOPOROSIS?
Osteoporosis is a bone condition, affecting more than 800,000 Australians as of 2022.
It’s a condition where the bones become fragile, weak and brittle, leading to a higher risk of fractures from minor bumps or accidents. While osteoporosis is sometimes assumed to affect older and elderly people, it can affect anyone of any gender, background and age, so bone health is important throughout your whole life!
‘Peak bone mass’ (or the most bone you will ever have) occurs by the early 20s, so it is important to maximise your lifetime ‘bone bank’ by being physically active during childhood and adolescence.
As most people only become health-conscious in their adult years, this window of opportunity has sometimes closed or is closing by the time they become aware of bone health. But don’t stress! It is never too late to take steps to enhance your bone health. Bone mass tends to decline from the mid-30s in sedentary people, but exercise can be used to temper and even reverse that loss.
GENERALLY, WE DON’T THINK OF OUR BONES UNLESS THEY BREAK
When bones break during childhood and young adulthood it is normally a result of an accident (falling from play or work equipment) or undertaking risky pastimes (skiing, violent contact sports, etc).
But when it happens in later life, during everyday activities like carrying groceries or picking up a grandchild, it is likely a sign of osteopenia (lower than normal bone mass) or osteoporosis (very low bone mass). Such fractures are referred to as low (or minimal) trauma fractures, indicating that the force that caused the bone to break was lower than would normally be expected to break the bone. In other words, if lower than normal bone mass was not present, the fractures are likely to not have happened or not have been so severe.
With severe osteoporosis, even coughing or a jolt from a stumble can cause a fracture. Hip fractures cause the most disability and reduction in quality of life, but vertebral fractures are more common and are associated with considerable pain, loss of height, and the development of a ‘dowager’s hump’ (exaggerated curvature of the upper spine) which reduces mobility.
RISK FACTORS FOR LOW BONE MASS
Ultimately, genes are the strongest determinant of peak bone mass, but biological sex, ageing, low body weight, and taking certain medicines over long periods (such as corticosteroids), are the primary risk factors for low bone mass and low trauma fractures in adulthood.
More women than men will have a low trauma fracture in their lifetime because women gain less bone than men during growth and lose more as they age due to the withdrawal of oestrogen at menopause.
HOW TO OPTIMISE AND INCREASE BONE MASS
Having adequate nutrition (especially calcium and vitamin D) is important for skeletal health but is not sufficient alone to prevent the development of osteopenia or osteoporosis.
The most important strategy to prevent low trauma fractures in older age is…you guessed it… exercise! But not all exercise builds bone.
A two-pronged approach to prevent fracture with exercise
Low trauma fractures are rarely due to low bone mass alone. Falls cause over 90% of hip fractures and contribute to other osteoporotic fractures, particularly in the arms, pelvis and spine. For this reason, any exercise program to prevent low trauma fractures must have two objectives:
1) to build bone and
2) to prevent falls.
What type of exercise improves bone?
Animal studies with tightly controlled loading have shown us that bone only increases in mass when exposed to loads that are notably larger than habitual loading or are applied very rapidly. Human studies have shown that, to build bone, loads should be applied while standing.
So, strength training or weightlifting with weights notably larger than you would usually carry (e.g. heavier than your usual bag of groceries) is the best approach for building and maintaining bone health. However, strength training must be done consistently and long-term to see these effects.
Indeed, exercise such as swimming and cycling, which are non-weight bearing, do not typically increase bone mass, despite potentially involving large muscle loads on the skeleton. Rather, heavy resistance and impact loading is required to stimulate bone.
Ironically, heavy rapid loads impart the exact type of forces that can cause low trauma fractures and are therefore cause for trepidation for people with fragile bones! For this reason, such exercise should only be prescribed under supervision by an exercise professional, like an Accredited Exercise Physiologist, with strict attention to proper technique and graduated increases.
The best example is the evidence-based Onero™ program developed from the results of the LIFTMOR and LIFTMOR-M trials which tested high-intensity resistance and impact training (HiRIT) in older women and men (respectively) with low to very low bone mass. HiRIT incorporates both heavy loads (lifting weights) and rapid loading (weight bearing impact).
Both trials showed HiRIT improved bone mass and strength, and importantly, improved muscle strength and function which reduced the risk of falling. Furthermore, the HiRIT program was safe, causing no low trauma fractures, due to close and expert supervision. Onero™ is offered at licensed providers around the country, such as The Bone Clinic in Brisbane. You can find your local Onero™ provider on the following map: https://onero.academy/locations/.
What type of exercise helps prevent falls?
To prevent falls, an independent exercise program must involve high challenge balance activities and be practiced around three times a week for at least 12 weeks.
‘High challenge’ means putting the body in a weight bearing position that increases the chances of falling, such as standing on one foot on an uneven surface or walking heel-to-toe along a slightly raised narrow beam.
Adding a second task such as simultaneously tossing a ball in the air while balancing will increase the challenge once the simpler task has been mastered. Naturally, such exercises should not be undertaken by individuals who are at increased risk of falling without fail safe strategies and appropriate supervision.
To make sure you’re exercising right to help prevent falls, chat to an Accredited Exercise Physiologist.
USE IT OR LOSE IT
To sustain improvements in both bone and balance, these targeted exercise programs must be ongoing. If the exercise programs stop, the benefits will be lost.
Luckily, bone and balance exercises also benefit the other tissues and systems in your body (heart, lungs, vessels, metabolism, brain, etc.), so lifelong exercise prescription to prevent low trauma fracture is a win-win!
EXERCISE RIGHT FOR BONE HEALTH
Overall, exercising regularly and utilising strength training at least twice a week from as young as possible will help build and maintain your bone health and reduce your risk of osteoporosis. So, if you haven’t started strength training, it’s never too late!
Make sure you’re exercising right for your ability, condition and health by chatting to an Accredited Exercise Physiologist (AEP).
Written by Prof. Belinda Beck | Ph.D., FACSM, FASBMR, ESSAF, FSMA
Director, The Bone Clinic
Director, Onero™
belinda@theboneclinic.com.au
www.theboneclinic.com.au
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