#10 THE SOFT-TISSUE STORY
WHAT YOUR BODY DOES
Just as your bones are influenced by your genetics and the lifestyle you lead (see previous section 'Them Bones'), so are your muscles. Your gender has the biggest effect on how big your muscles can get – as a rule, women generally have smaller, less bulky muscles than men. This is because testosterone drives muscle formation – and men have far more testosterone than women. A 30-year-old man will typically have a testosterone level of 270–1070 ng/dL, while a woman of the same age will have only 15–70 ng/dL. In other words, a woman has only about 6% of the testosterone of a man – so she has virtually no chance of ever looking like Arnie or The Rock.
Testosterone also affects muscle strength, but so does physical activity. An office worker who doesn’t do any physical work won’t be as strong as their colleague who cycles to work, goes to the gym three days a week and spends a lot of time working in the garden on the weekends. This is because your muscles respond to physical stress, just like your bones do. The way they respond depends on the type of stress you put on them.
# At the gym, if you’re lifting weights that are just a bit heavier than you can comfortably manage, you’ll be stressing the neuromuscular system. Your body detects this stress. One response is to activate cells called satellite cells. These are a type of stem cell, which means that they can turn into other cells when they get the right signal. When they get the go-ahead from your body, the satellite cells start multiplying. Some of them turn into myoblasts, which fuse with existing muscle tissue and both repair it and increase the size of the muscle. In nonscientific language, basically your body thinks: ‘Hmm, these weights are heavy, I need to make bigger, stronger muscles to cope with them’, and then sets about doing just that.
# Say that, instead, you run very long distances, day after day after day. Now your body doesn’t want large muscles – because this means a lot of extra weight to carry around, and your body wants to expend as little energy as necessary while it’s doing all this running. It does, however, want the ability to produce lots of energy in your muscles. It does this by increasing the number of mitochondria in your muscle cells. Mitochondria are like little power units: they burn glucose and fatty acids that are produced from our food, and so supply the energy that makes your muscles contract (along with fuelling a whole host of other metabolic processes). And it’s not just running – any type of endurance exercise will produce this effect.
Now, these aren’t one-way systems. If you lift weights for a week and then never touch them again, you’re not going to keep any muscle growth that you achieved. If you train to run one marathon in your twenties and then spend the next 10 years sitting on the couch, all of those extra mitochondria you had are going to die off. When it comes to muscle strength and mitochondria, if you don’t use it, then you’re going to lose it.
WHAT YOU CAN DO
When it comes to being healthy, most of us are after a balance. We want muscles that are strong but can also go the distance, so that we can run or walk or swim as long as we like. To get this, we need to do a variety of exercise, and do it consistently. If we only do one exercise, then yes, we’ll get good at it – but overall we won’t be balanced. If you just focus on lifting weights then you’ll easily be able to pick up your kids – but you might not be able to catch them!
BUILD EXERCISE INTO YOUR DAY
Fortunately, a lot of exercise can actually be built into your day – you don’t have to ‘do’ exercise in a certain way for a certain amount of time. Little and often is a great way to get your daily exercise. Check out the ‘Fit 5’ opposite for some ideas on how to integrate more activity into your day. What else would work for you?
DO FUNCTIONAL EXERCISE
It’s also important to know that your body doesn’t work like a series of isolated muscle movements. Your body is much more fluid – your muscles work in a coordinated way that produces actual functional movements like standing up, walking around, and bending down to pick something up. Think about the simple act of moving from the couch to the kitchen to get a cup of tea and a biscuit, then sitting down again to watch TV. There are dozens of movements involved – and none of them look anything like a bicep curl.
These functional movement patterns, which we use every day, developed as we evolved as a species. They’re hard-wired into our brains. The problem is that we don’t use them anywhere near as much now as we did even 50 years ago. We sit in a car to go to work, we sit at a desk all day, we sit in a café to eat our lunch, we sit in a car to come home, and we sit on a sofa to eat our dinner and watch TV. And guess what happens? Our bodies forget how to move. Our glutes switch off, our core becomes weak, our back muscles atrophy. We hunch and slump our way through the day, setting ourselves up for a future that’s likely to include disability and distress.
Luckily, you can do something about this. Including an exercise programme that’s built on functional movements that will re-educate your body and help return it to a strong, healthy state. You can build a body that will serve you well today and will also set you up for a healthy, active life in future years. To see how you can do this, take a look at the ‘Functional Fitness for All’ section on page 52.
FIT:5
Built-in exercise
- At work, the mall or the supermarket, park your car well away from the entrance and benefit from the extra bit of walking. Once you’re inside, take the stairs, not the elevator or escalator.
- Stand, don’t sit. Whenever possible, stand up when you’re talking on the phone, talking to people, even when you’re eating a meal.
- Wash your car yourself, rather than taking it through the carwash at the petrol station – you’ll get an all-over upper-body workout.
- Housework is actually great full-body exercise – even better if you put on some music and dance around as you do it!
- If you’ve got a garden, get out into it. If you’re paying someone else to look after it, they’re getting the exercise, not you.