For decades, we have been taught that to maintain basic aerobic fitness we need three 20-muinute aerobic training sessions per week. This is still good advice, but, as active Taekwondo athletes should not we do even more? The answer is no! To build quicker, more powerful kicks, you do not need extra aerobic activity, you need to train your muscles to kick quicker and more powerfully..
Everyone has some percentage of two basic types of muscle fibers: slow twitch (Type I) and fast twitch (Type II). The relative percentage of each type in each person is the result of genetics and training.
Slow twitch fibers are used in sustained aerobic activity, such as long runs. When you engage in aerobic activities for over 30 minutes you are developing this muscle fiber type and its supporting enzyme system. Developing these muscle fibers does not help you kick quicker and more powerfully, because slow twitch muscles have limited potential for both rapid force development and low anaerobic (high intensity) power.