Whey protein powder is the most important muscle-building supplement you can take, with essential benefits for everyone from casual gym-goers to elite sportsmen. But with so many choices, each with a variety of other substances and bewildering acronyms propping up their ingredients list, it can be difficult to know what you’re actually putting into your body – or if it’s even helping your training. Here's what you should look out for next time you reach for the scoop.

The benefits of whey protein

A study published in the Journal Of The International Society Of Sports Nutrition found that subjects who consumed whey protein after training experienced improved blood flow to their forearm muscles, enhancing the delivery of muscle-building nutrients such as oxygen and hormones. It is also generally understood that the anabolic effects of weight training are increased through the consumption of whey protein because amino acids are rapidly driven to skeletal muscle tissue. This helps your muscles get larger and stronger in less time than if you weren’t taking whey protein.

How much protein should you consume?

This debate has raged for years, but one thing that virtually everyone agrees on is that 2g per kilo is a good idea for the average gymgoer. This is also the ratio that was used in a 2015 study in which subjects lost fat while gaining muscle, long regarded as impossible for those not already eating enough chicken.

When to take whey protein

Take whey straight as soon after a workout as possible for a quick hit of muscle-building nutrients. Casein is the bedtime protein, and you should take it before you hit the hay for a prolonged release of protein to aid muscle recovery and growth. Soy protein is a vegan option derived from soya beans, and studies have shown that it, like the previous two, supports muscle hypertrophy.

What should I look for?
The word to remember is “bioavailability”. This pharmacological term refers to how much of your scoop – or rather, the amino acids in it – can actually be used by your body. It’s linked to biological value (BV), a unit of measurement that compares different protein sources via the nitrogen they allow to be stored in the body (bonus fact: if your powder causes, ah, emissions, that’s nitrogen being under-used). Eggs are the usual comparison unit, with a BV of 100. A typical “good” value for whey is about 104.

Are there different types of whey protein?

You bet. Concentrate whey protein is typically lower in fat than other forms and has higher amounts of carbs from lactose, the type of sugar found in milk products, and bioactive compounds. Protein content by weight can be anywhere between 30% and 90%.
Isolate whey protein is processed to remove fat and lactose, but it’s also lower in health-boosting bioactive compounds. Protein by weight content is 90% and higher.
Hydrolysate whey protein is pre-digested and partially hydrolysed, which means water is added during the production process to break down the constituent compounds. This makes them easier for your body to digest but also increases the cost.
Native whey protein is the purest form because it is extracted directly from skimmed milk rather than being a by-product of cheese production like concentrate and isolate. It is very low in fat, lactose and bioactive compounds, while its protein content by weight is typically 95% and higher.

If you’re trying to bulk up, it can be tempting to grab a pile of bargain-shelf cow remnants, but you wouldn’t expect them to provide the same glorious results as a grass-fed, 28-day aged ribeye steak. Similarly, when you’re looking for a powder, it can be tempting to head to your health food shop’s bargain aisle and grab the bucket of protein that offers the highest powder-to-pounds ratio, but by doing so you’re probably short-changing yourself. Go for quality, and the gains will come.

With so many companies making whey protein powders, it can be tricky knowing which to go for, specially considering the difference in prices between certain brands. While more expensive brands usually use isolate whey, rather than concentrate, that's not always the case so it’s worth reading the product description to find out. As a rule of thumb, check how long the brand has been around for. If they've been trading for ages, it’s a safe bet it’s a decent product. Having said that, most companies use the same – or very similar – protein in their products, it’s the flavour (and carbohydrate content) that drastically changes between different products.