Endurance plays an important role in many athletic activities. Without resistance training, many athletes would not be able to compete in their respective sports. Resistance training involves low resistance and high repetitions, but what exactly does this do to your body and how does it do it? For starters, resistance training increases the level of certain aerobic enzymes, which are necessary for the breakdown of fuels to produce energy. Enzymes are proteins that accelerate metabolic reactions; they release and transfer energy. Enzymes are affected by many factors: 1) Temperature: Activity increases when muscles are warm, so warming up before the actual activity is very important. 2) Acidity: Lower pH levels reduce enzyme activity, leading to fatigue. 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 occurs in the mitochondria. Oxygen is key to resistance training, so mitochondria are very important. Oxygen is needed to break down carbohydrates and fats, which provide energy. Dr. John Holloszy conducted an experiment to demonstrate the importance of mitochondria in resistance training. He had two groups of rats. One group was trained and eventually able to practice continuously for 4-8 hours. The untrained rats became tired after thirty minutes of exercise. Holloszy found a 50-60% 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 state profiles. They are generally classified as having lower levels of tension, depression, anger, tiredness and confusion. However, during periods of excessive training, levels of anger, anxiety and depression increase. Overall, however, endurance athletes are mentally healthier than the average athlete. Endurance is achieved by persevering with a lighter load. This means doing perhaps one set of 20-40 with ten pounds, instead of two sets of ten to twelve with twenty pounds. You progressively increase your workload. Consistency is very important. Resistance training lasts all week, all year. Resistance training affects every part of your body, physically and emotionally. It makes you a healthier and overall happier person. Endurance plays an important role in all of our athletic activities.