Train Hard, Replenish Harder

You celebrate how hard you train and how many calories you burn. You ignore what your workout takes from you. Exercise depletes more than fat stores; it drains the very resources you need to adapt.

First, energy loss. High-intensity exercise runs on glycogen-the carbohydrate stored in your muscles and liver. When glycogen drops, power and endurance evaporate. Post-exercise carbohydrate intake is critical; research shows that within the first two hours after training, ingesting about 1.2 g of carbohydrate per kilogram of body weight per hour is needed to maximize glycogen resynthesis. Skip this, and your next session suffers.

Second, fluid and mineral loss. Sweat is more than water; it contains sodium, potassium and magnesium. Athletes can lose more than 2 L of sweat per hour in hot conditions, and daily water and sodium losses can reach 4-10 L and 3.5-7 g respectively. Dehydration slows glycogen and protein synthesis. Rehydration should replace 125-150% of the weight you lose during exercise and must include electrolytes. Milk, oral rehydration solutions and electrolyte-rich drinks outperform plain water for retaining fluid.

Third, protein use. Training breaks down muscle proteins. Protein ingestion after exercise promotes muscle protein synthesis, reduces breakdown and helps repair tissue. Studies show that consuming 20-40 g of high-quality protein after exercise maximizes synthesis for several hours. Endurance athletes need about 1.2-1.8 g of protein per kilogram of body weight per day, while strength athletes require more. Distribute protein across meals every 3-4 h to maintain amino acid availability.

If you train hard but replenish poorly, you are breaking yourself down faster than you can rebuild. Replace glycogen with carbohydrates, rehydrate with fluids and electrolytes, and rebuild with protein. Stop treating nutrition as optional and wonder why you’re exhausted. Most people wait for pain to confirm what they already knew.

Reference: Naderi A et al., “Nutritional strategies to improve post-exercise recovery and subsequent exercise performance” (2025).