Incorporating rolling 400s into your weekly running routine can be a game-changer for half marathon training. This specific workout involves a structured session starting with a 1.25-mile warm-up at a conversational pace (no faster than 4.4 mph), which is essential to prepare your muscles and cardiovascular system for the intense intervals ahead. The main set repeats four times and consists of running 0.25 miles at a faster pace of 4.9 mph followed by 0.25 miles at a moderately paced 4.6 mph. This form of interval training helps improve both speed and aerobic capacity. The 90-second walking rest between intervals allows partial recovery without causing your heart rate to drop drastically, preserving the training effect. Completing the session with a 0.75-mile cool down at a conversational pace facilitates muscle recovery and reduces soreness. This workout plan is part of a 12-week half marathon training program, suggested around week 6, marking progress in building endurance and speed safely. From personal experience, sticking to a well-rounded plan that includes rolling 400s has noticeably increased my pace endurance. It also greatly helped me mentally by breaking the run into manageable segments rather than thinking of a long continuous effort. Incorporating similar workouts tailored to your pace can enhance your performance and readiness for race day. When training for a half marathon, consistency is key. Adding these rolling 400 intervals twice a week, as done here for the second run of the week, supports continuous improvement without overtraining. Remember to listen to your body and adjust paces slightly to match your fitness level. This approach keeps training motivating, safe, and effective for long-term running success.