Catherine Saxelby challenges the popular myth that protein builds extra muscle and makes you stronger.
Protein supplements, shakes and bars often make claims promising more muscle mass, greater strength and faster recovery. So it’s hardly surprising that many people believe these will bulk them up. But do they really work?
How muscles are created
Protein is the basic building material for muscle tissue. Protein in food is broken down in the body, then re-assembled.
Many athletes, particularly weight lifters, consume large amounts of protein, believing this will enhance the size and strength of their muscles. So you’d think that supplying more building blocks to the body would result in bigger muscles. But it doesn’t work that way – the body only takes what it needs and converts the rest into fuel.
How much protein do you need?
For most of us, the recommended daily intake of 0.8g protein per kilogram of body weight is fine. This translates to 56g protein for a 70kg woman and 72g protein for a 90kg man.
But this is too low for those serious about building muscle. Higher intakes – over 1g protein per kilo – have produced more strength gains than control groups, according to the Sports Dietitians Association of Australia. But this only applies to athletes who strength train four times a week and/or participate in aerobic exercise lasting 60–90 minutes three times a week. Beginner and intermediate exercisers generally don’t need an increased protein intake. However, if you are trying to build muscle, a high protein and carbohydrate snack before or after you exercise can promote gains in muscle size and strength. Remember, consuming huge amounts of protein alone does not stimulate muscle growth. They get bigger through a program of weights or resistance exercise, plus a healthy balanced diet.
Supplements vs food
There is no nutritional advantage to using protein powders or shakes over high-protein food. But protein powders and milk additives are convenient pre- and post-training snacks, and a lowbulk, easily prepared, portable form of food. They can also be a solution for athletes who struggle to eat enough food to meet their increased energy needs. Remember, they’re not pure protein (no food is). They contain carbohydrates, plus added vitamins and minerals.
The bottom line
If you strength-train regularly, you need a little more protein than the general population, but you can get all you need from food. If needed, protein powders are an easy way to meet increased energy needs.