400 Meters

The 400-meter is usually known as the longest sprint. It requires both speed as well as efficient anaerobic endurance. The athletes have to move fast and manage lactic acid accumulation. Although labeled as a sprint, the 400 is also associated with endurance training. It is approximately 43–60 seconds for competition and is an absolute full lap that challenges both short-distance and long-distance energy systems. Intervals (such as 300s and 500s), set work for lactic acid tolerance, and quick-pace runs make up training. Proper pacing is of major importance—coming out quick but in control, maintaining speed down the backstretch, and finishing the last 100 meters. The 400 helps the endurance runner be in shape for maintaining speed and withstanding fatigue, which is the key in races that have rapid finishes or short bursts of speed, such as in running, cycling, and triathlon.