Muscle is going through an image change. Previously thought of as a stretchy slab of inert flesh that declines with age, especially once we hit 50, research is emerging that suggests that the simple step of regular muscle execise, followed by a protein snack, could keep our muscles going long into old age. This not only means a better physique, but also a life less likely to be sabotaged by falls in later years.

Good muscles mean far more than the ability to lift weights, run fast or show off a washboard stomach. They are crucial to health: the muscles of our chest help us to breathe properly and keep the lungs free from fluid; muscles in the heart pump blood around the body; and, of course, muscles, literally, hold us up. Lose as little as 25 per cent of the muscle bulk in your leg and you’ll struggle to get out of a chair; you’ ll also find yourself tripping over kerbs or falling over in the shower.

As well as staving off old-age frailty, this recent muscle research, from the University of Nottingham and other universities across Europe, may also be important for cancer patients and athletes. Keeping on weight in the form of muscle means a better chance of recovery for cancer patients. And this new understanding of how muscle works may save gym bunnies a fortune.

The accepted story is that the muscle wasting seen with cancer, and the less dramatic muscle wasting of age, is because, over time, more muscle is being broken down than is being built up. In fact, breakdown rates remain pretty much the same. Scientists at the University of Nottingham have discovered that it is the build-up that’s the problem because the muscle is denying itself the nutrients it needs. Food is the key that switches on muscle-building and, more specifically, the amino acids found in protein, which are the building blocks for muscle production.

So the answer to bigger muscles surely is to eat more protein? Many clearly think so because the shelves of every healthfood shop groan with protein supplements for body builders. In fact, contrary to all received wisdom and a million internet sites, it’s not the answer.

First, and here’s a surprise, our body takes in only the exact amount of protein that it needs to build muscle; any more than that is expelled in our urine. This is because the amino acids that make up proteins are poisonous in large quantities and cause brain damage in excess, but we have loads of enzymes to break them down. So, the more protein we eat, the more the body raises its production of enzymes to break it down and excrete it in pee, keeping us safe from harm.

And so our muscles get full up. Literally. Once we’ve had the equivalent of a boiled egg’s worth of protein or so, muscles don’t take up any further amino acids, which means that those expensive protein supplements largely end up down the pan.

The concept of muscles being full up is highly significant because as we age our muscles say that they’ve had enough, earlier than they did when we were younger, meaning that without the necessary building blocks, muscle breakdown exceeds build-up. The technical name for it is anabolic blunting.

This effect is also probably highly significant in cancer because there is something about a tumour that causes it to react to the enemy within and to tell muscle that it’s full up way before it actually has. This process is common in cancer but also in several diseases that cause wasting – all this despite huge amounts of protein and calories being poured into patients via supplements and drips.

But here comes the good news: with moderate exercise, followed by a meal that contains some protein, we may be able to cheat this system. Michael Rennie, a professor of clinical physiology at the University of Nottingham, and who has an international reputation in this field, recommends cheap protein such as fish, eggs or mik. It doesn’t have to be a huge portion; a large glass of milk is enough.

According to Jacqueline Birtwisle, a registered sports nutritionist who works with the British rowing team, some good postexercise snacks are a wholemeal roll containing a sliced boiled egg, a fruit smoothie made with skimmed milk, or 200ml of skimmed milk with 50g of sugar-free muesli. Shift your pattern of feeding so that you don’t eat more protein every day, just eat more of it soon after exercise. By doing so you may preserve your muscle, avoid falls, and maintain good health for longer.

The effect is not confined to the young; even older people can have their muscle maintenance system effectively tweaked; rejuvenated effectively by about an hour of moderate resistance exercise. If you know someone with cancer, it may be worth encouraging them to stay active and, if possible, to start visiting the gym, and taking a light high-protein meal soon afterwards.

If you are a sportsman or woman, and eat to satisfy your appetite, you will automatically be getting more than enough protein in your ordinary diet to sustain muscle growth when you work out, whatever the advertisements tell you. If you just want to be more toned, especially if you are older, resistance exercise and food is the key.

But what sort of exercise works best for improving our muscles? Suprisingly perhaps, it’s not the sort of exercise needed for cardiovascu-lar fitness, such as long walks, swimming or sweaty stuff. Simply lifting weights will help, and not even heavy ones at that. And if you follow this resistance exercise with a meal containing protein, muscle-building accelerates.

Professor Rennie says: “What seems to be happening is that the muscle’s sensitivity to amino acids may be reset by exercise.” Exercise makes the muscle realise that it’s not actually full and that it could do with some more amino acids, which it then takes in to bulk itself up. This discovery is good news for older people but even better for those with cancer and diseases known to cause wasting such as chronic obstructive pulmonary disease and liver cirrhosis.

A study, completed recently by a group of researchers in Heidelberg (its leader, Wulf Hildebrant, will be joining Professor Rennie soon), shows that encouraging patients with pancreatic cancer to do resistance exercise reversed their weight loss and they put on muscle as fast as healthy people of the same age. “This is an important finding because better muscles should help them to cope better with surgery, have fewer complications and possibly speed recuperation,” Professor Rennie says.

Later Life Training runs courses to promote exercise for the elderly and the frail; www.laterlifetraining.co.uk

How to stay in shape

To get the most out of your muscles, supervised resistance exercises at the gym is the best bet. Meanwhile, here are some simple exercises you can do at home to help keep your muscles in shape. They can be done by anyone of any age, but older people, particularly if a bit unfit, should take things slowly.

Listen to your body, breathe, and don’t overdo it. If you are not sure of the technique, ask a professional. Don’t worry if you don’t have any equipment, bags of sugar work well as weights.

Legs Squats are the best. Imagine that you are getting in and out of a chair. Slowly. If you are a bit unstable, use a chair but try not to sit down fully, or make sure there is something to hold on to. Do three sets of 10.

Back These muscles are easy to work in the gym with upright rowing motions. At home, sit upright on the floor, slowly push your weights away from your chest and pull back again. Three sets of 10.

Chest Lie on the floor and push your weights up towards the ceiling and back down to your chest. Three sets of 10.

Tummy Simple crunches are best, and technique is crucial. Lie on the floor, feet flat, knees bent, hands on thighs, and press your back into the floor. As you slowly curl upwards, breathe out, making sure you look upwards at the ceiling. Three sets of 20.