Looking for the Old Website?

If you are member of the old Jillian Michaels website:

Please use this link to login:

Old Website Login

Old Website Help

What Is Anaerobic Fitness?

by Sam Ashe-Edmunds

Anaerobic fitness refers to your ability to function at a high intensity for short periods, then recover quickly afterwards. Sports such as tennis, football, basketball, soccer and volleyball require anaerobic fitness, which you can improve with specific training routines. Sprint training is an example of anaerobic exercise that helps you improve your anaerobic fitness. Use more sport-specific training as your season nears to improve your anaerobic conditioning.


Anaerobic exercise occurs at a very high intensity and does not use oxygen to provide energy to the muscles. After two minutes, activity becomes more aerobic, burning more fat, using more slow-twitch muscles fibers and producing more lactate.

Anaerobic vs. Aerobic

Aerobic exercise generally occurs when you work between 70 percent and 80 percent of your maximum heart rate. Your muscles use oxygen to function and you burn more of your calories from fat than during anaerobic exercise. Your muscles call upon slow-twitch muscle fibers to perform contractions. Anaerobic exercise occurs when you work at 80 percent or more of your maximum heart rate. You burn mostly glycogen and use more fast-twitch muscle fibers. Less lactate builds in your muscles during anaerobic exercise because, unlike during aerobic exercise, you remove lactate from your muscles during the frequent recovery periods.


A main feature of anaerobic fitness is your ability to recover after intense bouts of activity. Aerobic exercise does not train your cardiorespiratory system to recover quickly after activity. Recovery is especially important for athletes who need to recover after points and plays so they can start the next one efficiently. A hurry-up offense in football often benefits the team using it because the opposing team may not train anaerobically. If not, the defense will not be able to recover quickly after each play, resulting in tired players.


To improve your anaerobic conditioning, use sprint training. This requires you to work at a very high intensity for 30 seconds to two minutes, then take a short break before beginning another sprint. You don’t need to run to perform sprints. You can create short bursts of activity using dumbbells, resistance bands, a jump rope, elliptical, exercise bike or rowing machine. Mirror the times you’ll experience during a game or match. For example, elite tennis players perform on-court drills very hard for 30 seconds, then recover for 90 seconds before starting another sprint.

Photo Credits:

  • Wendy Hope/Stockbyte/Getty Images

This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.