If you know anything about exercise, then you're probably aware of two distinct methods people use: resistance-focused exercise and endurance-focused exercise.
While resistance exercise typically focuses on developing your anaerobic system and getting stronger, endurance exercise focuses on developing the aerobic system, which allows you to do more before tiring out.
Before we dive into these methods of exercise—including which one you should focus on— let's take a quick look at the two energy systems of the body.
Anaerobic Energy System
The anaerobic energy system is what your body uses during fast, explosive movements when there is not enough time for the body to send oxygen through the aerobic system.
While the anaerobic system is extremely fast and efficient, it tires out pretty quick. Resistance training is the best way to improve this system and ensure it remains in top shape.
Whether you're completing a heavy set of squats or sprinting away from a bear, if the activity is strenuous and lasts under 30 seconds, you are predominantly using your anaerobic system to supply the energy.
Aerobic Energy System
While the anaerobic system supplies energy for short, explosive activities, the aerobic system picks up the slack when exercise is long and drawn out.
Ever wonder why you can sprint a 100 meters but not a marathon?
That's because during the short sprint, the anaerobic system produces ATP, the body's fuel source, quickly. When the anaerobic system becomes tired, the aerobic system begins to take over the production. While the aerobic system lasts a long time, it takes even longer to send oxygen through the system to supply ATP. So, if you plan on using this energy system for exercise, you are bound by its limits.