In triathlon, training hours are easy to measure—rest isn’t. If you train 15 hours a week, here is what sports science proves about sleep: 🧬 Fast Muscle Repair: Up to 70% of growth hormone is released during deep sleep to rebuild broken muscle fibers. ⚡️ Faster Performance: Studies show endurance athletes who add just 30–60 minutes of sleep boost time-trial speeds by 3%. 🛡️ Fewer Injuries: Sleeping less than 8 hours a night makes you 1.7x more likely to get injured. 🔋 Full Energy: Deep sleep