Slow twitch muscles are noted for their endurance and have the ability to use large quantities of oxygen required for fat metabolism during aerobic exercise. Fast twitch muscles are the strength and power producing muscles. They are good for explosive bursts of anaerobic energy for sprinting, jumping, lifting and interval work. However, they fatigue fast and are not efficient fat burners. Glycogen is their main source of energy during intense work making them ideal for anaerobic exercise lasting up to three minutes.
Exercise lasting longer than three minutes is aerobic.
Q. Exercise physiologists have traditionally believed that volume, not intensity, is the key to successful aerobic training. A training program based on volume, such as running a hundred miles a week, will not maximize aerobic capacity or develop a high anaerobic capacity . What is required is a cross-training program encompassing aerobic and anaerobic workouts. During an LSD workout the heart rate is usually 75-85 percent of the age related maximum. Anaerobic running, on the other hand, consists of interval training at distance ranging from 200m to 800m, and for cycling 800m to 1500m, at a heart rate of 90-95 percent of maximum.