What is a good Interval Training Program?

Brian asked:


I am looking for some advice for an interval training program in order to increase my cardiovascular fitness over the next two weeks. I run about 15-20 miles per week and lift weights twice a week so I am in decent shape. I would like to improve my cardio ability and shorten my cardio recovery period over the next two weeks in preparation for a lacrosse tournament that I am playing in.

When I played in college, we used to train by jogging 2-3 mins, sprinting 1 min, then walking for 30 seconds to recover, then start over, repeating for about 30 mins.

Is this a good routine, or does anyone have better advice? Specific advice around the different levels and their durations, as well as overall interval workout length would be great. Thanks!