Sports nutrition is big business. For those of us who invest large amounts of time and energy to improve our PBs by fractions of a percentage point, the idea that we could almost effortlessly increase our gains just by taking the right supplements is a seductive one. There are lots of different kinds of sports supplements drinks available, all promising a different (but related) set of performance benefits. There are pre-workout drinks, post-workout drinks, meal replacement drinks, carbohydrate drinks and those containing specific nutrients or supplements claimed to enhance specific aspects of performance. To keep things reasonably simple, in this column, we’re just going to focus on protein drinks. These come in a variety of different formulations and flavors—whey is a common source of protein, but casein, egg protein, rice protein, pea protein and many others are available.

Is there actually any evidence to support the claims that protein shakes improve performance, enhance lean muscle mass or shorten recovery time after exercise?

There’s some evidence that focuses directly on supplements, although it’s mixed. A 2015 systematic review concluded that (amongst untrained subjects), protein supplementation had no significant effect on muscle strength or lean mass if the training stimulus was low, but as the duration and frequency of training increased, the supplements became beneficial. This may reflect the fact that most people already get enough protein in their diet to support a relatively low training volume. Another review published in 2014 points to a lack of evidence that protein supplements reduce post-exercise muscle soreness or improve recovery after training. It also suggests that any beneficial effects of protein are most noticeable for people who are in “negative nitrogen and/or energy balance.” In layman’s terms, if you aren’t already getting enough protein in your diet, then adding some more might be helpful.

Why supplements?

This is a key point. Looking at some sports nutrition marketing, you might get the idea that supplement shakes are some kind of magic potion: just drink this brand’s protein supplement, and you’ll wake up looking like Arnie, double your bench press and leap tall buildings with a single bound. The reality is that supplements are just that—they’re a way of supplementing your food intake. If you’re already getting enough protein to support your training in your diet (more about what “enough” looks like later) then adding extra in the form of shakes is unlikely to help you. Is there any particular reason why people might want to use shakes rather than just eating their protein? Maybe. Here are a few possible reasons.

1. Convenience and portability. A protein shake is easier to throw in your training bag than half a roast chicken, and less messy, too. It’s a well-known law of nutrition that hungry people will sooner or later reach for the Snickers bar, so if packing a protein shake makes that less likely, then that’s a win.
2. Ease of consumption. If you’re trying to gain muscle mass, then that takes a calorie surplus. If you’ve ever tried to bulk up, you may have discovered that it’s not as easy as people sometimes think it is. You won’t get any sympathy from anyone who’s dieting, but trying to force feed yourself that extra chicken breast when you’re really not hungry can be just as miserable as not eating enough. Drinking your calories makes it easier to get through more of them (which could also be a potential reason to avoid shakes if you’re trying to lose weight – but that might be balanced against other factors).
3. Individual dietary needs. If you’re on a restricted diet for either ethical or health reasons, then you may find supplements are a handy addition. It’s entirely possible for vegans (for example) to get enough good quality protein as part of a healthy balanced diet without resorting to supplements, but it does require a significant amount of planning and forethought. If you’re busy or disorganized, you might find it easier to include some supplements, especially during periods of hard training.

How much protein is enough?

There is ongoing debate about how much protein intake is necessary for good health. The DRI (Dietary Reference Intake) is 0.8g per kg of body weight for a sedentary individual. However, there is some evidence to suggest that, at least under some circumstances, increasing protein intake may have benefits for athletes and those undertaking resistance training. The Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine recommend 1.2 to 2.0 grams of protein per kilogram of body weight per day for athletes, depending on training. The International Society of Sports Nutrition recommends between 1.4 and 2.0 g / kg. They also comment that increased protein intake can help to prevent muscle loss during periods of energy restriction (also known as dieting).

Does the kind of protein matter?

Probably. We know that not all proteins are created equal, but there appears to be a lack of good evidence when it comes to comparing the performance benefits of different types of protein supplement. Look for complete proteins that are well digested. 

Is too much protein bad for me?

There have been some concerns that consuming too much protein could be unhealthy. In particular, there have been suggestions that it could damage the kidneys and lead to loss of calcium from the bones. This sounds alarming, but the evidence now suggests that protein intakes of up to 2.0 grams per kilo of bodyweight are safe for healthy, active individuals. This may not apply to people with existing kidney problems, who should seek individual advice from their doctor.  

The verdict: Partially TRUE, for some people.

Protein shakes are no magic potion; they aren’t any better for you than other sources of protein. However, some people may find them a useful and convenient way of increasing their protein intake to a level that supports their training. Ensuring that you are consuming enough protein IS beneficial; the amount you need will depend on the type, intensity, and volume of training that you are doing.