Despite the simplicity of running, this popular activity affects your body in a wide variety of ways. In addition to helping you burn calories, running improves your cardiorespiratory function by expanding your capacity to perform exercise and increasing the amount of work you can do. Running also helps you build muscular endurance.
Many people use the terms stamina and endurance interchangeably. Exercise professionals usually use stamina to refer to cardio function and endurance to refer to muscular function. Stamina is your ability to work longer, rather than harder. A sprinter might have more cardio capacity to do high-intensity work than a marathoner, but the distance runner has more stamina, or ability to use his heart and lungs longer.
Exercise professionals often use the term endurance to apply to your ability to use your muscles over time. Using the examples of a sprinter and marathoner, we can see that the faster runner will have more muscular power and speed, but the marathoner will be able to use her legs longer, or will have more muscular endurance. This is because sprinters train in short bursts of activity, while long-distance runners train their muscles for long periods.
Training for maximum speed engages your anaerobic energy system. You use high-twitch muscle fibers, burn mostly glycogen, and train your heart, lungs and muscle to recover after activity. When you work at a stamina-building pace, you call on your body’s aerobic energy system. You use more fat to fuel this work, use low-twitch muscle fibers and only recover at the end of your workout.
VO2 Max is the term that describes the maximum amount of oxygen you can use during sustained, high-intensity activity. Exercise professionals use it as a measurement of your fitness. Genetics play a role in your VO2 Max, but you can increase this measurement of your stamina with training, such as running.
The best way to build stamina is to work longer, not harder. Working at a higher intensity expands your capacity to work harder, but doesn’t help you work longer. Jogging, rather than sprinting, allows you to run longer, conditioning your heart, lung and muscles to adapt to longer bouts of stress.
If you are a beginner continue to work at the same pace as you build stamina, adding minutes or miles to your runs rather than trying to increase your speed or decrease your time. Start with a walk, raise your level to a jog, then raise your speed to a run. Raise your speeds only after you are able to exercise for the amount of time or distance that is your ultimate goal.