In this Article

• What is interval training?
• How are interval-training sessions designed?
• How do I determine how hard to work?
• How often should I increase the intensity of the intervals?
• How do I know how high my heart rate is?
• Can I do intervals inside or outside, with or without exercise equipment?
• How often should I do intervals?
• What are the advantages of interval training?
• Are there any disadvantages to interval training?
• What are the physiological effects of interval training and how do they increase fitness and performance?
• How do I know if I should do intervals?
• Will interval training help me burn more calories and more fat?
• Will interval training help me lose weight?
• Is circuit training an interval-training workout?
• Is interval training the same as cross-training?
• I'm a bodybuilder. Should I do intervals?
• Should I warm up before interval training?
• What should I do for a cool-down after interval work?
• Interval Training Index

How often should I increase the intensity of the intervals?

Interval training will improve your conditioning and performance quickly, usually in just a few weeks. As your conditioning improves, your heart rate will be lower at both the work and active-recovery interval even though you are training at the same speed you started the intervals with. When that happens, you increase the work ratio by one-half minute or even a full minute and decrease the active-recovery interval. For example, you change the 3:1 ratio to 2.5:1.5 or 2.0:2.0. You keep changing the ratio over the weeks until you are doing all the work intervals for four minutes and then you start over with a new 3:1 ratio.

Here's an example of a six-week program using one-minute interval increases.

Week one. 6 mph:7.5 mph (three minutes at 6 and one minute at 7.5)

Week two. 6 mph:7.5 mph (2.0:2.0)

Week three. 6 mph:7.5 mph (1:3)

Week four. 6 mph:7.5 mph (all at 7.5 mph for four minutes) Now a new interval at higher speeds

Week five. 6.5 mph:8 mph (3:1 minute)

Week six. 6.5 mph:8 mph (2:2)

Important: Intervals are tough, and so you might want to increase each week in half-minute intervals. You should be out of breath and sweaty during the work interval to make it work but not so hard that you out yourself at risk for injury. For instance, if you can't run at 7.5 mph because your legs simply won't go that fast, then don't do it. Instead, you can increase the incline of the treadmill, and outdoors you can perform the work interval on a hill. Listen to your body and experiment until you find what works best.

How do I know how high my heart rate is?

The intensity of your intervals will make it tough to remain still enough to monitor your heart rate with your hands or even with the monitor on your treadmill or bike. This is where a heart-rate monitor comes in. They are excellent tools for measuring intensity during intervals. Check out Polar heart-rate monitors online at www.polarusa.com. You can buy an inexpensive one for around $50-$60.