Running for fitness and/or competition can improve your cardiovascular system, lower your body fat and reduce you risk for metabolic disease. Running is classified as an aerobic activity because it uses rhythmic large-muscle dynamic movement for an extended period of time. Running on a regular basis will change your body inside and out.

Decreased Body Fat

Regular aerobic exercise like running increases you caloric burn both during exercise and for an extended period of time afterward. Because fat is an oxidative fuel, it is ideal for running, and will become your primary substrate as the length of your runs increases. As your body fat goes down, your muscles become more prominent, giving you an athletic physique. Not only will lower body fat improve your appearance, but it will reduce your risk of heart disease. To significantly change to your body fat, run consistently five to seven days per week for 30 to 60 minutes. Keep your intensity moderate to high for the greatest benefit to your health and appearance.

Improved Muscular Endurance

Running propels your body like a projectile, using continuous contractions in your leg muscles to keep your body in motion. Your quadriceps, hamstrings, glutes and calves contract and relax repeatedly throughout your run, improving their endurance by increasing their capacity to create energy via the breakdown of fats and carbohydrates. Improved muscular endurance will optimize your running performance, as well as improve your performance of everyday functional activities.

Strengthen the Heart

Your heart rate positively correlates to the intensity of your activity, and running can have a profound impact on your heart muscle. In response to high-intensity activity, your heart becomes stronger and more efficient at pumping blood throughout your body. As your cardiovascular endurance improves, your heart does not need to work as hard at rest because it can pump the necessary blood with fewer beats per minute, lowering your resting heart rate.

Improved Circulation

When you exercise, your heart beats faster and harder, and blood vessels dilate in order to get more blood to your working muscles. As you become more fit through running, your muscle cells, arteries, blood volume and lung capacity adapt to make the exchange of oxygen and carbon dioxide more efficient. You also develop more capillaries that aid in gas exchange. Improved circulation reduces your risk of arterial sclerosis and blockage of your arterial pathways that can lead to stroke and heart attack.