Is the chocolate milk a good recovery drink after a workout?

The best hydrating drinks are those the body retains the most of once they've been consumed. By doing studies where they give people different drinks in standardised conditions, scientists have been able to determine how various options stack up

Whether you enjoy chocolate milk regularly, as a weekend treat, or as an occasional dose of childhood nostalgia, it probably wouldn't be the first option you think of for post-workout recovery. Unless you're on TikTok, perhaps.

According to many people on the social media platform, chocolate milk is not only delicious, but it offers benefits comparable to sports drinks after a workout. So is there any evidence to support this? Let's take a look.

Rehydrating after a workout is important

Water accounts for somewhere between 50 per cent and 60 per cent of our body weight. Water has many important functions in the body, including helping to keep our body at the right temperature through sweating. We lose water naturally from our bodies when we sweat, as well as through our breathing and when we go to the toilet. So it's important to stay hydrated to replenish the water we lose. When we don't, we become dehydrated, which can put a strain on our bodies.

Signs and symptoms of dehydration can range from thirst and dizziness to low blood pressure and confusion. Athletes, because of their higher levels of exertion, lose more water through sweating and from respiration (when their breathing rate gets faster). If they're training or competing in hot or humid environments they will sweat even more. Dehydration impacts athletes' performance and like for all of us, can affect their health. So finding ways to ensure athletes rehydrate quickly during and after they train or compete is important.

Fortunately, sports scientists and dietitians have done research looking at the composition of different fluids to understand which ones rehydrate athletes most effectively.

The beverage hydration index

The best hydrating drinks are those the body retains the most of once they've been consumed. By doing studies where they give people different drinks in standardised conditions, scientists have been able to determine how various options stack up. To this end, they've developed something called the beverage hydration index, which measures to what degree different fluids hydrate a person compared to still water.

According to this index, beverages with similar fluid retention to still water include sparkling water, sports drinks, cola, diet cola, tea, coffee, and beer below 4 per cent alcohol. That said, alcohol is probably best avoided when recovering from exercise. Beverages with superior fluid retention to still water include milk (both full-fat and skim), soy milk, orange juice and oral rehydration solutions.

This body of research indicates that when it comes to rehydration after exercise, unflavoured milk (full fat, skim or soy) is better than sports drinks. But what about chocolate milk? A small study looked at the effects of chocolate milk compared to plain milk on rehydration and exercise performance in futsal players (futsal is similar to soccer but played on a court indoors). The researchers found no difference in rehydration between the two. There's no other published research to my knowledge looking at how chocolate milk compares to regular milk for rehydration during or after exercise. But rehydration isn't the only thing athletes look for in sports drinks. In the same study, drinking chocolate milk after play (referred to as the recovery period) increased the time it took for the futsal players to become exhausted in further exercise (a shuttle run test) four hours later. This was also shown in a review of several clinical trials. The analysis found that, compared to different placebos (such as water) or other drinks containing fat, protein and carbohydrates, chocolate milk lengthened the time to exhaustion during exercise.

What's in chocolate milk?

Milk contains protein, carbohydrates and electrolytes, each of which can affect hydration, performance, or both. Protein is important for building muscle, which is beneficial for performance. The electrolytes in milk (including sodium and potassium) help to replace electrolytes lost through sweating, so can also be good for performance, and aid hydration. Compared to regular milk, chocolate milk contains added sugar. This provides extra carbohydrates, which are likewise beneficial for performance. Carbohydrates provide an immediate source of energy for athletes' working muscles, where they're stored as glycogen. This might contribute to the edge chocolate milk appears to have over plain milk in terms of athletic endurance.

Coffee-flavoured milk has an additional advantage. It contains caffeine, which can improve athletic performance by reducing the perceived effort that goes into exercise. One study showed that a frappe-type drink prepared with filtered coffee, skim milk and sugar led to better muscle glycogen levels after exercise compared to plain milk with an equivalent amount of sugar added.

So what's the verdict?

Evidence shows chocolate milk can rehydrate better than water or sports drinks after exercise. But there isn't evidence to suggest it can rehydrate better than plain milk. Chocolate milk does appear to improve athletic endurance compared to plain milk though. Ultimately, the best drink for athletes to consume to rehydrate is the one they're most likely to drink. While many TikTok trends are not based on evidence, it seems chocolate milk could actually be a good option for recovery from exercise. And it will be cheaper than specialised sports nutrition products. You can buy different brands from the supermarket or make your own at home with a drinking chocolate powder. This doesn't mean everyone should look to chocolate milk when they're feeling thirsty. Chocolate milk does have more calories than plain milk and many other drinks because of the added sugar. For most of us, chocolate milk may be best enjoyed as an occasional treat.

(The author is from University of South Australia)