Let's go for it! 3 to 4 hours of aerobic endurance riding spent between 65-75% FTP (73 km neutral zone @ 260 W, double rubberband strength, turns off 5 km left) These group endurance rides are aimed at improving your aerobic power production capabilities in a steady, low-stress manner. By training your endurance muscle fibers to better utilize oxygen to metabolize fat as fuel, your muscles can spare sugar stores for more intense efforts. This long/slow approach to fostering aerobic capabilities is the lighter, kinder alternative to high-intensity repeats, but both approaches target many of the same adaptations. Try to keep your spin above 85rpm, preferably above 95rpm. The entire session should feel really very easy. Consume 40-60g of carbohydrates per hour.