What is it?
Interval training is a type of training that involves "bursts" of high intensity activity with rest periods separating them. Interval training can be done as a setting on a treadmill/elliptical, done during a spin workout, or a run.
What are the benefits of interval training?
A major benefit of interval training for running is that is is the most efficient way to make you faster. Think about it- say you run 9 minute miles, and you want to get your mile time down to 8 minutes. If you just went out for a run and started dropping 1 minute off of every mile you run, you would burn out quickly and not get very far. If you alternate your pace (say half a mile at a 9 minute pace, half a mile at a 7.5 minute pace) you won't burn out nearly as quickly.
The other (probably more popular) benefit of interval training is that it burns more calories than a steady paced cardiovascular workout. The bursts of activity make a huge impact on the workload. Today, during my 4 mile interval workout my i phone said I burned 520 calories, and my previous steady paced 4 mile run on the same route burned only 460 calories.
Are there any limitations I should be aware of?
Yes- interval training should only be done once or twice a week. These short bursts of energy are wonderful and all, but they tire your muscles and CV (cardiovascular) system pretty quickly, making you more prone to injury. You should also change your work:rest ratio in order to maximize the benefits of training and further reduce risk of injury.
So what's a good interval workout?
Today, my workout was alternating my pace every half mile for four miles. I ran at about a 9.5 minute pace for a half a mile, then at a 7 minute pace for a half a mile. I measured the distance and pace by using my swanky new i phone app- so it was pretty easy to monitor.
Another popular way to do interval training is by timing as opposed to distance. For example, run or walk at your normal pace for 4 minutes, then for the fifth minute, increase the intensity, and when the fifth minute is over go back to your normal pace for another four minutes.
If you're time is limited, you can do this really quick interval workout and feel like you just ran 10 miles:
Happy Training =)