Sprint while you commute?

If you're under 25 and in reasonably good shape, I suppose you could try this exercise regimen ...

Can You Get Fit in Six Minutes a Week? - Well Blog - NYTimes.com

... In one of the group’s recent studies, Gibala and his colleagues had a group of college students, who were healthy but not athletes, ride a stationary bike at a sustainable pace for between 90 and 120 minutes. Another set of students grunted through a series of short, strenuous intervals: 20 to 30 seconds of cycling at the highest intensity the riders could stand. After resting for four minutes, the students pedaled hard again for another 20 to 30 seconds, repeating the cycle four to six times (depending on how much each person could stand), “for a total of two to three minutes of very intense exercise per training session,” Gibala says.

Each of the two groups exercised three times a week. After two weeks, both groups showed almost identical increases in their endurance (as measured in a stationary bicycle time trial), even though the one group had exercised for six to nine minutes per week, and the other about five hours. Additionally, molecular changes that signal increased fitness were evident equally in both groups. ... In other words, six minutes or so a week of hard exercise (plus the time spent warming up, cooling down, and resting between the bouts of intense work) had proven to be as good as multiple hours of working out for achieving fitness. The short, intense workouts aided in weight loss, too, although Gibala hadn’t been studying that effect.

The response has been found in rat studies, so it's a little bit plausible.

If you're not under 25 several caveats apply

• The study results need to be replicated with larger groups and older participants.
• The news article didn't mention gender. Maybe this only works for young men with lots of testosterone on board.
• The risk of injury with extremely intense workouts is high.
• This is a good way to die if you're over 25 and aren't accustomed to repeated levels of intense exertion.
• I suspect when they say "intense" they mean an intensity level that most older people can't reach (short of death).
• Most Americans are exercising for weight loss.
• Maybe we'll find out it causes accelerate atherosclerosis (you never know ...)

That said, if you're young, healthy and reasonably fit, it would be easy to work this kind of routine into a commonplace 30 minute bicycle commute. Just don't do it on a 10 mph bicycle trail!