The Renaissance Diet 2.0. Mike Israetel

that the gastrointestinal tract can absorb per hour. If you show up to hard training or competition a little dehydrated, you are already behind. Before training or competition, make sure you are taking in regular fluids and monitoring your weight and urine color to stay well hydrated. When daily bodyweight varies during fat-loss or muscle-gain phases, urine color becomes your best tool to monitor pre-training hydration.

      Intra-Training Hydration

      Around 5 fl. oz. per 20 minutes of hard exertion is a baseline recommendation for hydration during training or competition. This can be lower in cooler and less difficult training scenarios and higher in hotter and more strenuous ones. Consuming electrolytes with this fluid is highly recommended. This can be done using sports drinks or by adding electrolyte tablets or powders to water.

      Post-Training Hydration

      As we mentioned earlier, your GI tract does not absorb all the fluid you drink; about one-third is lost in urine. This means that if you lose 2 lb. of sweat during your training session, you actually need to consume 3 lb. of fluids after training to fully rehydrate. Rehydration should occur somewhat gradually for comfort and best fluid absorption. A general guideline is about 8 oz of fluid every 15 minutes after training until the required total is met. If the fluid has electrolytes or is consumed with food, euhydration will be reached more quickly as electrolytes facilitate water absorption. Drinking large amounts of water without electrolytes, especially over a short period of time, can cause a dangerous electrolyte deficiency called hyponatremia.