Once you have a base of regular walking or running for at least six months, you should be ready to increase the intensity level with interval training. Interval training can be done on a treadmill by repeating a pattern of a high-speed period followed by a short recovery period throughout your workout. The key is to not allow your body to get comfortable during the workout so it has to work harder. This will become a valuable part of your treadmill regimen and ultimately increase your fitness.
Interval training can be done on a treadmill by varying the speed. Start with a warm-up period of easy walking or jogging. Before beginning an interval workout, your body must be completely warm with all muscles loose and flexible. Otherwise, you risk injury.
Start with a speed setting that is slower than normal for the warm-up period. Then find a base mph setting that is slightly above the warm-up speed. This will be the speed you come back to for recovery periods. Once you have your base, build on that speed every two minutes.
For example, if your warm-up speed is 3.0 mph, your base or recovery speed could be 4.0 mph. Speed periods would start at 4.5 mph for one minute, then 4.0 for one minute of recovery. The next minute would be at 5.0, then 4.0 again for another minute. Continue to increase the speed period every other minute to 5.5, 6.0, 6.5 and so on while keeping your recovery at 4.0. This pattern should be continued throughout the middle portion of your workout, lasting for 10 to 20 minutes. Always follow with a complete cool-down period.
The other option for interval training on a treadmill is to vary the incline setting. Start with a warm-up period on a relatively flat elevation at 1.0. When you are ready for the interval portion of your workout, increase the elevation for one minute, then recover at 1.0 for one minute. Keep the mph setting the same throughout. Your workout will get harder by changing the elevation, not the speed.
For example, run for one minute at 1.5 incline, then recover for one minute at 1.0, run for the next minute at 2.0, recover at 1.0. Continue to increase the incline every other minute to 2.5, 3.0, 3.5 and so on while keeping your recovery period at 1.0.
The length of the intervals can vary. One minute is a good starting point, but if you are a beginner, you can start at 30 seconds. If you are more advanced, you can make it two minutes. The goal is to keep the recovery period as short as possible, while still allowing your body enough time to recover. The more fit you get, the quicker your body will recover and the shorter your recovery period can be.
Here is a sample treadmill interval workout:
Warm-up, 10 minutes at 3.0 mph Gradually increase the setting to 4.5 mph and allow your body to adjust to this speed. Then: Run for one minute at 4.5 mph Recover for one minute at 3.5 mph Run for one minute at 5.0 mph Recover for one minute at 3.5 mph Run for one minute at 5.5 mph Recover for one minute at 3.5 mph
Continue to increase the speed at each interval and repeat this pattern for 10 to 20 minutes.
Cool down for 10 minutes at 3.0 mph.
The benefits of interval training can be substantial. You will burn more calories during and after your workout, get faster and stronger, and increase overall cardiovascular fitness. Interval training also relieves the boredom sometimes associated with treadmill training.