In the world of endurance sports, carbohydrates are king, and for good reason. Carbohydrates are our primary and most efficient fuel source for sustained activities like running and cycling, as well as intermittent efforts such as HYROX, rugby, and netball. Most athletes understand their importance and, thanks to the accessibility of foods like bread, fruit, vegetables, rice, and pasta, generally consume adequate amounts.
Across my 20 years as an endurance athlete and coach, I’ve consistently seen the critical role carbohydrates play. When intake falls short, performance quickly follows: low energy, reduced output, and a lack of motivation are early warning signs. The feedback loop is immediate and hard to ignore. Because of this, there’s relatively little left to uncover about carbohydrates in the endurance space.
Protein, however, is a different story.
The first step in understanding the importance of protein for endurance athletes is recognising its role. Adequate protein intake supports muscle, tendon, and ligament repair and growth, drives mitochondrial adaptations, strengthens immune function, and contributes to improved sleep quality. Ultimately, meeting daily protein requirements supports training consistency through better recovery and overall health.
The next question is how much to consume. Current guidelines suggest around 1.0 g/kg of body weight per day for recreational endurance athletes, and up to 1.8 g/kg for elite competitors. For me, as an 85 kg male, that equates to roughly 85–153 grams of protein per day, depending on training demands.
So what does that look like in real-world terms?
High-protein foods include animal-based sources such as beef, chicken, fish, and eggs; dairy options like milk, yoghurt, and cheese; and plant-based sources including lentils, tofu, beans, nuts, and seeds. What often surprises people, however, is how much of these foods is required to meet daily protein targets. For example, per 100 grams:
- Chicken breast: ~30g
- Lean beef: ~25g
- Eggs: ~13g
- Greek yoghurt: ~8–10g
- Tofu: ~10–17g
- Beans: ~21g
- Lentils: ~9g
- Mixed nuts: ~24g
When working with endurance athletes who are frequently sick or injured, I look closely at protein intake alongside their training load. Endurance training is inherently catabolic—it breaks down tissue (e.g. muscle) and depletes stored energy (e.g. glycogen). Without adequate protein to support repair and adaptation, recovery is compromised, immune function declines, and the risk of illness or injury increases.
Because protein intake often requires more planning, cost, and attention to detail than carbohydrates, it’s usually the first area I address before fine-tuning carbohydrate intake.
For many athletes, time is the biggest barrier.
They juggle full-time work, family commitments, and demanding training schedules. It’s common to hear about a quick sandwich on the go, followed by coffee, or a banana or muesli bar before training. While these choices help meet carbohydrate needs, they do little to support daily protein targets.
This is where high-quality protein supplements can play a practical role.
While whole foods should always form the foundation of an athlete’s diet, protein powders offer a convenient way to add 18–24 grams of protein per serve. I often recommend using them in the morning to support satiety, or before bed to aid recovery, immune function, and sleep, all with minimal time or effort.
Carbohydrates will always deserve their place in the endurance spotlight, but not at the expense of protein. Once viewed primarily as a tool for strength and power athletes, protein is now recognised as equally important for endurance performance. While endurance athletes may not be chasing muscle size, they stand to gain from improved recovery, reduced illness risk, better sleep, and more consistent performance.
Meet your protein needs, and you give yourself the best chance to train consistently, stay healthy, and perform closer to your potential.
