Adapting one’s diet to their sports practice is not just about eating more or choosing the latest trendy supplement. Sports nutrition relies on a balance between energy intake, macronutrient distribution, and synchronization with effort. Measuring the gap between what the body expends and what it receives allows for the identification of concrete improvement levers, whether one is a regular runner or a weightlifter.
Relative Energy Deficiency in Athletes: An Underestimated Risk
Most nutritional guides for athletes focus on what to eat. Few address the consequences of insufficient intake compared to actual expenditure. The consensus from the International Olympic Committee published in 2023 (Mountjoy et al., British Journal of Sports Medicine) describes Relative Energy Deficiency in Sport (REDs) as a set of physiological and psychological repercussions related to chronic energy underconsumption.
This syndrome does not only affect female athletes. REDs concerns all athletes, both men and women, and can lead to hormonal, bone, immune, or hematological disorders. Performance decreases, and the risk of injury increases.
The long-used threshold of 30 kcal per kilogram of lean body mass per day is no longer considered a standalone diagnosis. Current recommendations favor a continuum of clinical assessment that integrates sex, training load, body composition, hormonal health, and injury history. In other words, two athletes with the same caloric intake can find themselves in radically different situations.
Finding nutritional information on Y a du Sport helps structure meals according to these individual parameters.
Macronutrients and Performance: Comparison by Type of Effort
The distribution of carbohydrates, proteins, and fats varies according to the sport practiced. An endurance runner and a weightlifter do not have the same nutritional priorities, even though both need sufficient energy intake.
| Parameter | Endurance Sport | Strength Sport |
|---|---|---|
| Carbohydrate Priority | High (glycogen replenishment) | Moderate (energy during the session) |
| Protein Needs | Moderate (tissue repair) | High (muscle synthesis) |
| Role of Fats | Energy source for long efforts | Hormonal regulation |
| Post-Effort Window | Carbohydrates + proteins quickly | Priority on proteins |
| Main Risk in Case of Underconsumption | Decreased endurance, REDs | Stagnation, muscle catabolism |
In endurance, carbohydrates are the primary fuel. A glycogen deficit results in premature fatigue and a drop in the ability to maintain intensity. In contrast, for strength sports, protein intake directly conditions muscle recovery and progression.
Fats should not be neglected in either case. They contribute to hormonal regulation (testosterone, thyroid hormones) and provide energy during prolonged efforts at moderate intensity.
Meal Timing Around Training: What Really Changes
Eating the right foods is not enough if the timing is wrong. The synchronization between meals and effort affects energy availability, digestion quality, and recovery capacity.
Before the Effort
A meal rich in complex carbohydrates, consumed two to three hours before the session, helps fill glycogen stores without overloading the digestive system. During intense effort, blood flow is redirected to the working muscles, which slows digestion. A meal that is too heavy or too close to the effort can cause gastrointestinal issues.
During the Effort
For long sessions (beyond one hour at sustained intensity), regular carbohydrate intake maintains blood sugar levels and delays exhaustion. Quick-digesting foods (dried fruits, carbohydrate gels) are preferred.
After the Effort
The post-effort window is when protein synthesis is most receptive. Combining carbohydrates and proteins within two hours after the session accelerates glycogen replenishment and muscle fiber repair.
- Moderate to high glycemic index carbohydrates to quickly restore energy reserves
- Complete proteins (containing all amino acids) to stimulate muscle reconstruction
- Sufficient hydration to compensate for sweat losses and facilitate nutrient transport
Dietary Supplements for Athletes: Safety and Banned Substances
The market for supplements aimed at athletes lacks uniform regulation. Some products, particularly pre-workouts, may contain substances banned by anti-doping agencies without clear labeling. This risk also concerns amateur athletes who are not subject to testing, as these substances can pose health dangers.
Before incorporating a supplement into their routine, checking the ingredient list and prioritizing products certified by an independent organization remains the minimum precaution. Protein powders, creatine, and caffeine are among the most studied and well-tolerated supplements, but their usefulness depends on the level of practice and the quality of the basic diet.
- Check the product certification (anti-doping standards) before any purchase
- Prioritize supplements whose effectiveness is documented by scientific literature
- Never compensate for a global dietary deficit with an isolated supplement
A supplement does not correct an unbalanced diet. If total energy intake is insufficient, adding protein powder will not resolve fatigue or stagnation.
Sports nutrition is becoming more precise as research progresses. The common thread among all disciplines remains the alignment between expenditure and intake: eating enough, at the right time, with the right nutrients. REDs, long ignored outside of high-level sports, reminds us that underconsumption is as detrimental as imbalance. Adjusting one’s diet based on individual indicators rather than generic recommendations remains the most reliable approach.
