Another Study on the Efficacy of Brief Intense Exercise

NSCA's Performance Training Journal quickly summarizes yet another study demonstrating that you get more bang for your buck doing intense intervals rather than traditional endurance training:

The sprint training group performed four to six all out maximal (~700 w) 30 second sprints separated by four minutes of recovery. The traditional endurance training group performed continuous exercise for 90 - 120 minutes at an intensity of 65% of maximal aerobic capacity or a power output of 175 W.

You can click through for the results, but I've already told you which one comes out on top. As a bonus, you don't compromise your speed and power training by eschewing the long slow stuff. And you save time:

When comparing the time commitment of the two protocols the sprint training required 2.5 hours while the traditional endurance training program required 10.5 hours.

A quick Google Scholar search turns up a bunch of similar-looking studies (which I have not read).