It’s not there just for vanity and to allow us to move around, muscle is an organ in its own right that has many impressive functions.
Obviously the stronger and bigger your muscles are, the more stuff you can move around or lift at the gym, but muscle tissue is of critical importance when it comes to maintaining good health, especially glucose control and regulation. Not having enough muscle increases the risk of developing type 2 diabetes, heart disease, falls, frailty and fractures and it is also associated with dementia.
The link between muscle and bone
An under-recognised condition in the medical world is sarcopenia – thinning of the muscles. We build strong muscles in childhood and reach peak muscle mass at around age 30-35 years, with a gradual decline in the amount of muscle mass in both sexes from our 40s.
Bones and muscles develop and grow together from the same basic tissues when a baby forms in the womb and stay connected forever. They act as a “muscle-bone unit,” communicating with each other in two ways:
- Mechanically: Strong muscles support and protect bones.
- Chemically: Both muscle and bone release signals that help each other stay healthy.
It is well known that the mechanical pull of the muscles on bones can strengthen bone, but the discovery that muscles and bones “talk” to each other through chemical signals has only been discovered in the last couple of decades. When muscles are contracting, they release substances called myokines. There is more being discovered all the time but essentially these chemical signals have far-reaching effects on many organs in the body and critically within the bones.
In fact, in a recent study from Edith Cowan University which focused on breast cancer survivors, researchers found that just one session of resistance training or high-intensity interval training (HIIT) significantly increased levels of myokines by as much as 30%.
Thinning of the bones
Osteoporosis and osteopenia (thinning of the bones, a precursor to the more advanced osteoporosis) are conditions that disproportionately affect women in ever greater numbers as we age. The menopause and subsequent loss of oestrogen is a major factor within this and all the bones within the body can be affected. Therefore it is critically important to identify early menopause, periods stopping before the age of 45 and Premature Ovarian Insufficiency (POI), periods stopping before the age of 40. As there are no symptoms of this bone thinning process taking place – it does not cause any aches and pains as is commonly thought and is often missed until too late – the first sign of something being wrong is when a patient sustains a fracture or break of bones.
We reach peak bone mass at around the age of 25-30 years and how much we manage to lay down will depend upon many factors including our genetic potential, family history, how active we were in childhood, adequate intake of calcium and vitamin D, and use of certain medications.
Increasing sedentary behaviour causes less movement of muscle tissue and decreased generation of myokines and mechanical stress on the bones. Therefore osteoporosis and sarcopenia often go hand in hand, with loss of bone mass and loss of muscle mass. This condition is termed Osteosarcopenia, with women affected more often than men of the same age, making up around two-thirds (65%) of cases. The co-existence of thin bones and weak muscles increases greatly the risk of falls and fractures more than having just one of the conditions alone. So, when muscle and bone are both weak, the chances of falling and breaking a bone are much higher.
All fractures are serious, but hip fractures are especially dangerous:
- Around 1 in 10 people die within a month of a hip fracture.
- Around 1 in 3 die within a year.
- Hip fractures cost the NHS £75 million per year for hospital care alone.
Most hip fractures (95%) happen after a fall, and women are nearly 3 times more likely than men to be affected.
How does menopause affect muscle and bone?
Oestrogen is well known to build strong bones, so when levels reduce after menopause we see the density or thickness of all the bones in the body start to fall. HRT and other non-hormonal bone building medication can slow and reverse this process.
Weak muscles increase the risk of falling because of reduced strength, poor balance and stability, slower walking, less ability to “catch” yourself if you trip.
So, when muscle and bone are both weak, the chances of falling and breaking a bone are much higher.
The jury is still out in terms of what effect hormones and the reduction of them has on muscle tissue. Studies so far show some changes but we haven’t as yet been able to show that HRT and/or testosterone therapy can prevent muscle mass loss with ageing. We know there are testosterone and oestrogen receptors on muscle tissue and within the connective tissue that sticks bones and joints together – studies are ongoing so watch this space!
Where to start to prevent loss of muscle
- Maximise your gains: Take the opportunity in your younger years to build good habits, such as adequate protein, active lifestyle and resistance exercise.
- Maintain activity throughout life: It is never too late to slow the decline or even make gains.
Resistance exercise can be safely started by even using your own body weight, with no fancy gym of heavy weights required.
The most important thing is to reduce inactivity but not get injured! Start with small but manageable habits, such as 10 body weight squats while the kettle boils. Go slowly, work until you are feeling a fatigue in the muscles and focus on getting your technique right. As you progress, start increasing the weights and work to around 3 sets of 6-10 repetitions in all the major muscle groups of the body.
I know first-hand the demands as a working mother on my time and energy and it is not always easy to prioritise your own needs. However, the data is very clear – resistance exercise and activity in general is crucial for maintaining health and avoiding frailty as we age. Start looking at exercise as a non-negotiable for your health and wellbeing and embed it as a habit in the same way as brushing your teeth.
