Nutrition and Sports: The Impact of Macronutrients on Performance
When it comes to improving your athletic performance, training is only half the equation. The other half is how you fuel your body—specifically, your balance of protein, carbohydrates, and fat (the macronutrients). The right balance supports more consistent energy during workouts, better recovery, and more predictable changes in body composition.
In this article, we break down the role of each macronutrient in performance and recovery. We also provide practical guidelines: protein intake (g/kg), carbohydrate intake (including carbohydrates per hour for long workouts), and a simple method for adjusting your macros based on your goal (strength, endurance, or fat loss).
The Role of Protein in Muscle Recovery and Growth
Protein supports muscle repair and adaptation, especially after a strength training or high-intensity workout. For most people who exercise, the most commonly cited range is 1.4 to 2.0 grams of protein per kilogram of body weight per day, to be adjusted based on the training phase and goals.
A practical approach is to spread protein intake throughout the day rather than concentrating it in a single meal. Many sports nutrition guidelines recommend 20 to 40 g of high-quality protein per serving (or about 0.25 to 0.40 g/kg), taken every few hours, as a regimen that promotes muscle protein synthesis and recovery.
Examples of foods: eggs, yogurt, lean meats, fish, tofu, legumes, and high-protein dairy products, depending on your tolerance and preferences.
How much protein do you need?
- Active individuals: approximately 1.4 to 2.0 g/kg/day
- Per meal or per serving: usually 20 to 40 g
Carbohydrates: The Body's Main Source of Energy
Carbohydrates are the body’s most efficient fuel for intense workouts, repeated efforts, and long sessions where glycogen stores are crucial. Choosing primarily high-fiber sources (whole grains, fruits, vegetables, legumes) helps maintain more stable energy levels, while fast-digesting carbohydrates can be helpful around the time of a workout.
For endurance exercise lasting more than an hour, the most commonly cited recommendations (including those from the ACSM) often suggest 30 to 60 grams of carbohydrates per hour to support performance and prevent fatigue.
If your workouts regularly last longer than two hours, some guidelines suggest that higher intake levels (more than 60 g/hour) may be beneficial, but you should first test them during training to check for digestive tolerance.
Carbohydrate intake per hour (endurance): approximately 30 to 60 g/hour for exercise lasting more than one hour.
The Importance of Healthy Fats in a Balanced Diet
Fats support hormone production, the absorption of fat-soluble vitamins, and cellular health—all of which are important when you exercise regularly and put your body under stress. They are also a concentrated source of energy, which is especially useful for long, low-intensity workouts.
The recommended range for athletes is 20 to 35 percent of total daily calories. Quality matters: choose olive oil, nuts, seeds, avocados, and fatty fish, and keep saturated fat intake in check as part of an overall balanced diet.
Hydration: The Unsung Hero of Performance
Hydration supports temperature regulation, nutrient transport, and recovery. Even a slight deficit can make training more difficult. Sports nutrition guidelines frequently note that performance declines as soon as dehydration becomes significant; in endurance sports, the risk often increases when body weight loss exceeds about 2 percent.
A simple moisturizing routine:
- Make sure you're hydrated before your workout (don't try to "catch up" during the session)
- Drink regularly in small sips during long sessions
- Consider taking electrolytes if you're sweating heavily or in hot weather, especially during long workouts
Finding the Right Balance Based on Your Goals
There is no one-size-fits-all macronutrient breakdown: the ideal balance depends on your type of workout, your weekly training volume, your recovery needs, and your goal. It can be summarized as follows:
If your goal is strength or muscle gain:
- Maintain a consistent daily protein intake (guideline in g/kg)
- Use carbohydrates to support the quality and progress of your workouts
- Maintain stable lipid levels for hormones and satiety
If your goal is endurance performance:
- Carbohydrates generally become the main source of energy (especially during long workouts)
- Protein supports recovery from training
- Fats are still important, but don't keep your fat intake too low over the long term
If your goal is to lose body fat without sacrificing performance:
- Make sure you get enough protein to preserve lean body mass and support recovery
- Don't cut out carbs so abruptly that your training performance takes a nosedive
- Use fats to make meals filling and satisfying over the long term
A plan tailored to your workout routine and lifestyle?
I'm Louis Fabre, a personal trainer in Paris. I help my clients build strength, improve their performance, and stick to their routine—without relying on generic programs that don't last.
If you're not sure how to balance protein, carbs, and fat based on your goals, I'll create a plan tailored to your workout schedule, lifestyle, and preferences—so you can make consistent progress week after week. For muscle gain, check out our strength training coaching in Paris.
Book your first session, and let's work together to develop a clear and realistic strategy for training, recovery, and nutrition.
