There is a lot to be said about interval training - particularly high intensity interval training. Interval training has the potential to:

• boost metabolism
• improve aerobic capacity
• increase overall running speed (if running is your thing - swimming, cycling or any other endurance sport apply)
• jump starts the endorphins that give us a workout high

Today's workout is going to be based on your perceived exertion level, and will combine a little bit of lower body strength training as well.  You'll work through five (5) 6-minute cycles (not including rest or warm up). Each cycle will progressively become more difficult. If you're up to the challenge, the entire workout should be wrapped up within 45 minutes.

Start this workout with a warm up* of about 10 minutes. (Scale of 1 to 10, warm up to about a 5). Go immediately into cycle 1:

*For this post, I'm going to use running as the aerobic portion of the workout. You can substitute cycling, elliptical, stair climber, rower, etc.

Cycle 1
4 minutes of moderate-paced running (scale of 1 to 10, push yourself to a 6 or 7)
1 minute of fast-paced running (scale of 1 to 10, push yourself to an 8 or 9)
1 minute of body weight squats (Not sure just how to do a body weight squat? See the bottom of this post)

Rest 2 minutes

Cycle 2
3 minutes of moderate-paced running
2 minutes of fast-paced running
1 minute of body weight squats

Rest 2 minutes

Cycle 3
2 minutes of moderate-paced running
3 minutes of fast-paced running
1 minute of body weight squats

Rest 2 minutes

Cycle 4
1 minutes of moderate-paced running
4 minutes of fast-paced running
1 minute of body weight squats

Rest 2 minutes

Cycle 5
5 minutes of fast-paced running
1 minute of body weight squats

Rest 2 minutes

*Body Weight Squats are done by standing with your feet hip-width apart, toes pointing straight ahead. I like to recommend people bring their hands straight out in front of them at shoulder height. If you're hands drop down or point toward the ground, your back isn't as straight as it should be.

Drop down into a squat, hold briefly, and return to standing. Make sure your knees stay in line with your toes.

You've got five cycles of 60-second body weight squats. You should be able to get in 20 squats per minute. That's 100 squats your butt and thighs will thank you for!