Table of Contents Track and Field Events Warming up Training Training Tips Cells and Bones Joints and Muscles Movement and Muscle Fibers Energy Production in the Body The Cardio-respiratory System Nutrition and Calories Nutrients, Proteins and Carbohydrates Fats, Vitamins, Minerals, Water and Fiber Record Breakers Did you know? (Cool Track Facts) Track and Field Links Bibliography Chimacum Middle School ThinkQuest Jr. Please give us Feedback about our site. Contact us! Meet the Team Featured site: The International Amateur Athletics Federation

Around the Track and Back Anatomy and Phisiology Basics, cont'd: Movement, cont'd In actions that our bodies are required to do everyday, movement comes about as the result of the contraction of groups of muscles. Effort is needed to make a single movement, the more the effort the greater the action. Training programs should always provide balance by developing muscles and their opposing muscles, like the tricep and the bicep. When one trains and works a muscle without working the opposing muscle, the weaker muscle may be injured. Training both muscles helps avoid injury. The two types of Muscle Fibers In each muscle there are two types of muscle fiber, fast twitch and slow twitch fibers. Different people have different amounts of fast and slow twitch fibers. Fast twitch muscles produce high speed movements for short periods of time. These types of muscle fibers are great for sprinters. Fast twitch muscle fibers produce large amounts of lactic acid, a waste which is what makes your muscles tire and stop working. That is why sprint races are shorter than distance races, because muscles cannot sprint for very long without getting too fatigued. Slow twitch fibers produce less speed but they can do it for much longer. The waste that slow twitch fibers produce are easily disposed of which makes slow twitch fibers essential for distance events where endurance is needed. Athletes with more slow twitch fibers need to do sprint training to improve their speed and athletes with mostly fast twitch fibers need to do a lot of endurance training. Overall, athletes with mostly slow twitch fibers should try out for distance and endurance events while athletes with fast twitch fibers should try out for sprint events.