Gyms are strange places. Within one room you find a cross section of society – rich, poor, young and old – getting sweaty and breathless together.

There’s lots of reasons why we would choose to clamber aboard a cycling/jogging/gyrating machine that moves nowhere. For many of us, it is about the personal challenge of getting fitter and enjoying the health benefits. For others, vanity is the driving force.

Whatever the motivation, one thing is for certain: there’s no shortage of people selling a shortcut to your goals. We shouldn’t be too surprised then, to learn that lots of these pricey purchases are about as useful as a packet of fairy dust. And high on the list of unnecessary sports products are protein supplements.

Having arrived hot on the heels of sugary sports drinks, protein shakes, powders and confectionery bars are now a common sight in gym changing rooms everywhere.

A few years ago, no-one had heard of ‘sports nutrition’. Now a plastic protein flask is a gym accessory must-have. However, unless you are an elite athlete or extremely malnourished, a protein supplement is highly unlikely to give you any kind of boost.

Here’s why: whenever we do regular exercise, we are triggering our body to adapt to the strains we place on it. Our body builds muscle, improves heart strength and circulation, and enhances lung capacity over many weeks and months. It is in the times between each workout that our body is working away to repair and strengthen muscles. It uses the nutrients in our diet to do this and of these proteins are the building blocks.

For many years it was thought that consuming copious amounts of protein would enhance such muscle development – resulting in a meaner, leaner physique.

However, a growing body of research now shows that this simply isn’t true. Eating too much protein is simply overloading the system.

A balanced diet containing good sources of protein (alongside all the other food groups) should give us everything that we need – even if we are doing serious training.

A 75kg male athlete, for example, will need 90g of protein a day – tops (slightly less for a woman). A normal diet will easily achieve this: a cup of yoghurt for breakfast, a tin of tuna with lunch and a chicken fillet at dinner. Eating more than this will force your body to expel it – literally passing it down the toilet bowl as urine. Research also shows too much could increase cancer risk and lower life expectancy.

Premade protein bars and drinks often have added sugars and so rarely represent good, wholesome nutrition. Even a basic twice daily protein shake regimen adds 500 calories to your day’s energy intake – equivalent to two chocolate bars. And unless you don’t do a lot of training or have your meals carefully planned, this could easily result in piling on unwanted weight gain – as fat.

I was prompted to write a critique about protein supplements after a friend in the gym told me he was scared of stopping drinking protein shakes. He said that he feared losing the muscle strength he had gained while taking them. The facts just don’t support this – protein powders are a powerful placebos: people think they are fitter because they buy expensive supplements.

Low fat dairy, lean meat and fish are excellent sources of protein, contain many vital nutrients, and will give the same physical benefits as expensive whey proteins. For a healthy post-workout drink, a large glass of skimmed milk has been shown to aid recovery and help weight loss. Add some fruit if you like and it will look great in one of those protein shakers.