Why should we be thinking about our bone health?
We all know someone who’s broken a bone, it can happen at any age and in any number of ways. Usually the bone will mend readily and life gets back to normal swiftly but in other cases the probability of fracture is much greater, it can flag up other medical conditions and sometimes the impact can be catastrophic.
The good news Is that you can boost your bone health and the evidence shows that one of the most effective ways to do this is through exercise.
We think of bones as solid structures but in fact they are dynamic and constantly remodelling like so many other human body tissues. A complex system of hormonal signalling and cellular process enables bone to rebuild and repair, responding to the many and varied activities and environments we encounter.
The blueprint for this incredible infrastructure is predetermined largely by our genes. Then, during our growth years we build our bone mass (which is likely to maintain throughout our lives), peaking in adolescence. During this growth phase we have a greater capacity to add new bone to skeleton.
Many factors including hormones, medications, certain medical conditions can have subtle positive and negative effects on bone tissue as we age. Similarly lifestyle choices – diet, exercicse, alcohol and smoking influence bone health. Bones need weight bearing and conversely early space travel proved that weightlessness causes healthy fit young astronauts to rapidly lose their bone density.
After adolescence the next critical time for bone health in women is the menopause transition. Whilst both men and women see declining bone stocks as they get older, women are four times more likely to experience bone loss. Some evidence suggests that women can lose as much as 25% of their bone mass during this time and the falling level of oestrogen is one of the main culprits for this.
Osteoporosis is a condition of weakened bones through loss of bone mineral density and bone mineral composition. Essentially the bone becomes more fragile and more likely to break. Often it is not identified until a minor fall or sudden impact causes a fracture, but typically the process will have been happening silently and slowly over years. The most common sites of injury are the wrist, hip and spine. The impact on the spine is often characterised by a loss of height leading to a stooped posture of the mid back.
Exercise is free, accessible and an effective way to:
- Maintain the bone you already have,
- Slow the loss as you get older and
- Boost your bone health, even if it’s started to become depleted.
The phrase ‘ use it or lose it’ is very apt. Bones, much like muscle, respond positively to use. Loading, especially via weight bearing activities but also through muscular action, will encourage the bone tissue to adapt and re-enforce itself.
What and how much exercise helps boost our bones?
Weight bearing exercises are when your feet and legs support your weight, for example walking. Higher impact activities such as jogging or running increase the load and therefore increase the musculo-skeletal demands, but crucially also the adaptive response. These are all good ways of boosting your bone health.
Muscle strengthening exercises for example press ups, require and build muscular strength; the action of a muscle-tendon unit pulling on its boney attachment will stimulate and increase bone modelling. So muscle strengthening is also beneficial to bone health.
Ideally you need a combination of both of these types of exercise.
Adults (19 to 64)
NHS recommendations advocate performing 2 hours and 30 minutes of moderate-intensity aerobic exercise each week. Aerobic (some people think of it as ‘cardio’) just means exercise with oxygen – so the sort of exercise where you feel your heart going and your breathing rate speeding up – but not so much that you get out of breath and have to stop. For example, 30 minutes of really brisk walking, five times per week would fit the NHS recommendation.
Cycling and rowing whilst fantastic and aerobic are partial weight bearing rather than full weight bearing forms of exercise. Swimming is aerobic but non weight bearing. Tennis, jogging, dancing and zumba are all examples of full weight bearing and aerobic exercise, and thus offer enhanced bone health benefits.
So mix it up!
In addition muscle strengthening on two or more days is recommended. This should be whole body using the major muscle groups of the arms legs and torso, working with weights or resistance bands.
Exercise for early post-menopausal women.
Research has shown that many forms of exercise performed by this population, when compared with a matched sedentary cohort, demonstrate positive effects on bone physiology – namely bone mineral density (BMD) and bone mineral composition (BMC).
Greater results are achieved with a combination of aerobic and resistance training, as detailed above.
These effects are further enhanced when combined with diet, supplementation and in some cases medication and hormone therapies.
One such study showed that BMD improvements were seen after one year of regular aerobic exercise (5 x per week brisk walking for 30 minutes) contrasting with an average 1% decline in the sedentary group.
Guidelines recommend two or more strength training sessions per week, for example begin with ten exercises working the major muscle groups of the arms, legs, abdomen and back, performing progressive sets of 8 -12 repetitions for each muscle group. In order to achieve an adequate strengthening effect you will probably require weights and resistance bands as well as working with your body weight.
One study following the above suggestion asked early post-menopausal women to perform strengthening exercises three times a week for a year (working at an intensity of either 40% or 80% of their 1 rep max for each muscle group). After 6 months both groups were stronger, having worked regularly at either intensity level. BMD also improved in both groups but did not show significant changes until one year.
Low demand aerobic exercise such as easy walking has been shown to help slow the decline in bone health, but is not adequate to show significant increases in BMD.
The addition of higher impact exercise and strengthening is still recommended to optimize benefits, even in those with osteoporosis.
This can be complicated by the extent of the osteoporosis or co-existing conditions and injuries, so here are some tips and ways of mixing up resistance, aerobic, partial- and full-weight bearing activities .
10 minute bouts of intense activity
… such as a burst of fast walking on your daily stroll, cycling super fast on your ergo or adding hills on the treadmill.
Take the stairs! A few minutes up and / or down is highly effective.
Water aerobics can be good for early return to fitness, everyday weights such as carrying shopping or heavy gardening all count.
Lower limb strength training
Make your home a gym – squats, bridging, side lying leg raises, calf raises and weights. In a group of people with known osteoporosis at the hip, leg strengthening was shown to be more effective for BMD improvements than even intensive walking.
Spinal strength & flexibility
Yoga, Tai-chi, Ballet and Pilates all combine weight bearing with the positive addition of balance, stretching and postural strength.
Don’t forget the arms
Wrists are a common fracture site in those with osteoporosis. ‘Downward dog’ in yoga is super for wrist bone health, similarly ‘planking’ in Pilates.
Ball squeezing, resistance bands, wall press ups and carrying groceries in both arms would all help.
Vibration training is excellent e.g. power plate, particularly for those who can’t tolerate higher impact.
Interestingly a recent study showed post-menopausal women under 65 who performed 3 months of thrice weekly whole body vibration training, showed improved BMD in the spine.
Prevention is always better than cure.
But if you are at risk or already have weakened bones then exercise can be an effective, enjoyable and a free way of improving bone health.
Should you have any questions or would like some guidance on what you could be doing, please don’t hesitate to ask one of our team at Richmond Physiotherapy.