Endurance plays a major role in many sporting activities. Without endurance training, many athletes would not be able to compete in their respective sports. Endurance training involves low resistance and high repetitions, but what exactly does that do to your body and how does it do it? For starters, endurance training increases the level of certain aerobic enzymes, which are necessary for breaking down fuels to produce energy. Enzymes are proteins that speed up metabolic reactions; they release and transfer energy. Enzymes are influenced by many factors: 1) Temperature: Activity is increased when muscles are warm, so it is very important to warm up before actual activity. 2) Acidity: Lower pH levels reduce enzyme activity, leading to fatigue. 3) Fuel: Enzymes work faster when muscles are warm. they have more fuel. The faster the enzyme can break down your body's fuel, the faster you will receive energy. Training also increases the number and size of mitochondria. Mitochondria are cellular powerhouses that produce energy aerobically. All oxidative energy production takes place in the mitochondria. Oxygen is key to endurance training, which is why mitochondria are very important. Oxygen is needed to break down carbohydrates and fats, which provide energy. Dr. John Holloszy conducted an experiment to prove the importance of mitochondria in endurance training. He had two groups of rats. A group was formed and was eventually able to exercise continuously for four to eight hours. The untrained rats became tired after thirty minutes of exercise. Holloszy found a fifty to sixty percent increase in mitochondrial protein and a twofold increase in oxygen consumption in the muscles of trained rats. This...... middle of paper ...... Endurance athletes have been found to have healthier mood profiles. They are generally classified as having lower levels of tension, depression, anger, fatigue and confusion. However, during periods of overtraining, levels of anger, anxiety and depression increase. However, overall, endurance athletes are in better mental health than the average athlete. Endurance is acquired through perseverance with a lighter load. This means doing maybe one set of 20 to 40 with ten books, instead of two sets of ten to twelve with twenty books. You gradually increase your workload. Consistency is very important. Endurance training takes place all week, all year round. Endurance training affects every part of your body, physically and emotionally. This makes you a healthier and overall happier person. Endurance plays a major role in all our sporting activities.