Demand for nutrition supplements and similar products may be up, yet experts are sceptical about their actual benefits.
"People who do regular exercise have a small increased need for protein," according to Dr Helen Crawley, reader in nutrition policy at City University London.
"But it is unlikely they need supplements of protein in any form as most western diets are already high in protein and people who are active eat more food and therefore these needs are generally covered.
"Most of the specialist foods available just have added skimmed milk powder to make them higher in protein, so whether a bar or drink or powder, they are just an expensive way of taking in extra calories."
Carbohydrate is the best fuel for exercise, whereas recovery from exercise is aided by taking low protein, carbohydrate-rich drinks and foods, such as banana and squash, she explains.
But beyond being useless, the supplements could even cause harm, Dr Crawley says.
"High protein intakes can in fact be dangerous and can damage kidneys and therefore protein supplements are not recommended," she says.