Whey Protein for Endurance Athletes: Do Runners and Cyclists Need It?

Protein supplements are usually linked to the weights room, so many runners and cyclists assume whey is not for them. Endurance training is about carbohydrate, mileage and pacing, the thinking goes, not about a protein shake. Yet research on endurance athletes paints a more complete picture. In this article we look at why endurance athletes need protein too, how much they need and whether a whey shake actually has a place in a runner or cyclist routine.

Why endurance athletes need protein too

Endurance training does more to your muscles than just burn fuel. Long runs and rides cause small amounts of muscle damage and place a constant repair demand on the body. Protein supplies the amino acids needed to rebuild that tissue and to maintain the muscle you rely on, kilometre after kilometre. Without enough protein, recovery slows and the risk of breaking down muscle during heavy training blocks rises.

There is also a less obvious role. Endurance training drives adaptations inside the muscle, such as building the structures that produce energy aerobically. These adaptations are built from protein, so a steady supply supports the very changes that make you a better endurance athlete. A review of protein nutrition for endurance athletes describes this as a focus on recovery and training adaptation, not just muscle size.

How much protein endurance athletes need

The amount of protein an endurance athlete needs sits higher than the basic recommendation for someone who is mostly inactive. General guidance for athletes points to a range of roughly 1.2 to 1.6 grams of protein per kilogram of body weight per day, and endurance athletes in heavy training often sit in the upper part of that range. Older work on protein requirements for endurance athletes already showed that high training volumes raise the need above the standard intake.

This does not mean endurance athletes need as much protein as bodybuilders chasing maximum size, but it is clearly more than the minimum for a sedentary person. The position stand from the International Society of Sports Nutrition supports intakes in this higher range to maintain and repair muscle in people who train hard. The exact number depends on your weight, your training load and your goals.

Protein during and after long sessions

For most endurance sessions, carbohydrate remains the main fuel you need before and during exercise. Protein becomes important mainly around recovery. After a long or hard session, a combination of carbohydrate and protein helps restock energy and starts the repair of worked muscle. This is where a whey shake fits naturally, because it is a fast and convenient source of protein when you may not feel like a full meal.

Some research has looked at adding protein to carbohydrate during very long efforts. Studies on endurance runners comparing carbohydrate alone with carbohydrate plus protein found that the combined approach can reduce markers of muscle damage and support endurance capacity in certain settings. The effect is not dramatic for everyone, but for athletes doing repeated hard sessions, less muscle damage can mean better recovery between workouts.

Does whey help performance

It is important to be honest about what whey does and does not do for endurance. A protein shake will not directly make you faster the way targeted training and good pacing will. What it can do is support the recovery that lets you train consistently. Consistent training, week after week, is what builds endurance, so anything that helps you bounce back from hard sessions has an indirect value.

Whey is simply a practical tool to hit your protein target. It is quickly digested, easy to carry and easy to mix after a session when appetite is often low. None of that is magic, but for a busy runner or cyclist it can be the difference between reaching your protein goal and falling short on heavy training days.

Carbohydrate still comes first

One mistake some endurance athletes make is to focus so much on protein that they neglect carbohydrate. For endurance performance, carbohydrate is the fuel that powers long efforts and refills your glycogen stores. Protein supports recovery, but it does not replace the carbohydrate you need to train and race well. A good approach treats protein as a steady daily habit and carbohydrate as the fuel matched to your training demands.

In practice this means a recovery shake after a long ride might include both carbohydrate and protein, not protein alone. The protein looks after repair while the carbohydrate restores energy. Getting the balance right matters more than chasing either nutrient on its own.

Practical ways to use whey as an endurance athlete

If you train for distance, a few simple habits make whey useful. Use a shake after long or hard sessions when a full meal is not practical, ideally with some carbohydrate alongside. Spread your protein across the day rather than loading it all into one meal, since regular portions support repair better. On easy days you may not need a shake at all if your meals already cover your protein.

Whey is also handy on busy days when work or travel gets in the way of cooking. A scoop with milk or a plant drink is a quick way to top up protein without much effort. The goal is to support your training, not to add unnecessary calories, so use it where it fills a real gap rather than out of habit.

How much do you actually need

Because protein needs depend on your weight, your training and your goals, a quick calculation beats guessing. Work out your daily target with our protein calculator so you know how much you really need as an endurance athlete and can plan your meals and shakes around it. That keeps you from both under eating protein and overdoing the shakes.

Aim to spread your protein in portions of roughly twenty to forty grams per meal across the day. This pattern supports muscle repair more effectively than one large serving and fits naturally around training sessions. With your target clear, whey becomes a simple way to fill the gaps rather than a guess.

Conclusion

Endurance athletes need protein, even if they need less than a bodybuilder and even if carbohydrate remains their main fuel. Protein supports the recovery and adaptation that consistent training depends on, and whey is a convenient way to reach your target on heavy days. Keep carbohydrate as your training fuel, treat protein as a steady daily habit and use a shake where it genuinely helps.

Sources

• Moore DR, et al. Protein Nutrition for Endurance Athletes: A Metabolic Focus on Promoting Recovery and Training Adaptation. Sports Med. 2025. PubMed 40117058
• Jager R, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017. PubMed 28642676
• Tarnopolsky M. Protein requirements for endurance athletes. Nutrition. 2004. PubMed 15212749
• Hsu YJ, et al. Effects of carbohydrate and protein supplement strategies on endurance capacity and muscle damage of endurance runners. J Int Soc Sports Nutr. 2022. PubMed 36250147