Sports nutrition is not just about choosing between pasta and rice the night before a competition. When comparing the eating habits of amateur athletes to the recommendations from the latest scientific consensus, significant gaps emerge, particularly regarding energy availability management, the actual role of supplements, and the timing of nutrient intake. This article reviews these gaps to identify the nutritional levers that can concretely modify sports performance on a daily basis.
Energy Availability and Performance: Game-Changing Data
Most nutrition guides for athletes focus on macronutrients. They overlook a more fundamental parameter: energy availability, which is the energy remaining after subtracting the expenditure related to training.
The consensus from the International Olympic Committee published in 2023 describes Relative Energy Deficiency in Sport (REDs) as a set of physiological and psychological consequences caused by insufficient caloric intake relative to the training load. This syndrome does not only affect female athletes: men and amateur athletes are also concerned.
Daily warning signs to watch for include:
- Persistent fatigue despite adequate sleep, associated with a regular decline in training performance
- Repeated infections (colds, sore throats) indicating immune system weakening due to caloric deficit
- Hormonal disorders or stress fractures, advanced signs of prolonged imbalance
The IOC 2023 consensus also warns against using a universal clinical threshold for energy availability. The often-cited threshold of 30 kcal/kg of lean mass per day does not apply to everyone, as many individual factors modify the risk. The assessment should integrate symptoms, changes in training load, hormonal health, and bone health.
The articles published on the nutrition section on Infos Sport detail these mechanisms in an accessible manner for non-professional practitioners.
Carbohydrates, Proteins, Fats: Comparative Table of Priorities According to Type of Effort
An endurance workout and a weight training session do not engage the same energy pathways. The table below summarizes the nutritional priorities based on the type of sports activity practiced.
| Criterion | Endurance Effort (running, cycling, swimming) | Strength Effort (weight training, crossfit) |
|---|---|---|
| Priority Macronutrient | Carbohydrates (muscle glycogen replenishment) | Proteins (muscle synthesis and repair) |
| Pre-effort Meal Timing | Meal rich in complex carbohydrates, 2 to 3 hours before | Mixed carbohydrate/protein meal, 2 hours before |
| Post-effort Recovery | Carbohydrates prioritized within 30 minutes, then proteins | Proteins prioritized, complemented by carbohydrates |
| Role of Fats | Energy source for very long efforts | Hormonal support (testosterone, growth hormones) |
What stands out from this comparison is that carbohydrates remain the primary fuel for endurance performance. Very restrictive carbohydrate diets limit the ability to sustain prolonged effort. In contrast, for strength sports, a regular protein intake spread throughout the day plays a more decisive role than the amount of carbohydrates.
Adapting Meals to Training Week
Nutritional periodization involves adjusting caloric intake and macronutrient distribution based on the intensity of the week. Rest days or light training do not require the same volume of carbohydrates as a day with long or intense sessions.
Increasing carbohydrates on effort days and reducing them on rest days allows for better energy management without accumulating unnecessary surplus. This approach, advocated by the IOC 2023 consensus, replaces the logic of “the same diet every day” with a diet modulated according to actual load.
Dietary Supplements for Athletes: What Science Really Says
The market for dietary supplements for athletes represents a considerable volume, but the majority of products sold lack solid evidence of efficacy. The IOC 2023 consensus clearly distinguishes between substances with demonstrated effects and those that fall under marketing.
Key points to remember include:
- Caffeine and creatine are among the few supplements whose effects on performance are supported by converging scientific data
- BCAAs (branched-chain amino acids), long popular, do not provide additional benefits when dietary protein intake is already sufficient
- The safety of supplements remains a blind spot: contamination by banned substances, inaccurate dosages, or unverified claims are documented risks
Addressing REDs starts with increasing food intake, not by adding a supplement. If fatigue persists, adjusting the training load takes precedence over any supplementation.
Hydration and Electrolytes: Personalize Rather Than Standardize
Generic recommendations like “drink 1.5 liters per day” do not take into account individual variability in sweating. Two athletes performing the same effort under the same conditions may lose very different amounts of sodium.
The dosage of electrolytes in sports drinks should be adapted to the intensity, duration, and climatic conditions. An excess of water without sodium intake can lead to hyponatremia, a potentially dangerous imbalance during prolonged efforts.
The most reliable approach is to observe the color of urine (light yellow as a marker of good hydration) and adjust the concentration of electrolytes according to the duration of the effort rather than following a fixed protocol.
When Hydration Becomes a Recovery Lever
After exertion, rehydration directly contributes to the quality of muscle recovery. Combining water, sodium, and carbohydrates in the minutes following an intense session accelerates glycogen restoration and reabsorption of lost fluids.
Daily sports nutrition relies less on miracle foods and more on three measurable mechanisms: maintaining sufficient energy availability, adjusting macronutrients to the type of actual effort, and personalizing hydration rather than following universal thresholds. These three parameters, taken together, have a more pronounced effect on performance than any dietary supplement.
