Sounds like an unrealistic promise, right? But it's not – and I have the American College of Sports Medicine as support for me. They suggest that you do 30 minutes of moderate exercise three times a week for 20 minutes of intense exercise, or 30 minutes of most days of the week (usually "5" being usually translated as 5). So 60 minutes versus 150 minutes – which means you reduce your training time more than halfway .
Here's my suggestion to maximize those 20 minutes while doing your sweaty session. Flyby: Tabata training, in which you work extremely hard for 20 seconds, rest for 1
The method was named after the Japanese scientist Izumi Tabata, who did a small but groundbreaking study. Participants were asked to alternate 20 seconds of total cycling with a rest period of 10 seconds for a total of 4 minutes. They made 7 to 8 sets of them, then repeated the process 5 weeks a week for 6 weeks. Here's the cool part: These guys have been more supportive of their fitness than others who have pedaled 5 times a week for 6 weeks at a moderate pace. You have read this correctly: those who have worked half as long have achieved better results thanks to their intensity.
I discovered Tabata last summer when I released a great DVD called Breathless Body by Amy Dixon, an LA-based trainer and sports physiologist. Dixon's training is based on the Tabata method (and has become one of my favorite training DVDs). Then last week, I came across a superb new indoor cycling DVD named Short & Sweet (the name is lightweight, but the workouts are not), which includes a 20-minute Tabata session, among other things.  Getty Images
You do not even need a DVD . You can run Tabata while running, cycling, skating and swimming – virtually any cardiovascular activity that you can work intensively on. Just go out for 20 seconds and then rest for 10 seconds (you want a programmable interval timer or a timer). Do this 8 times, rest for a few minutes and then do it again. Repeat this four more times, and you're done.
But here's the thing: "walking out" does not mean working harder than usual. "It must be an effort emptying the tank," says Dixon. "It must be a 10 on a scale of 1 to 10." You have to work everything you have so hard that you can barely stand the 20 seconds. And no, you will not feel fully recovered after the ten seconds of rest (if you do not, you have not worked hard enough). And yes, you will probably grunt and curse almost every 20-second block, especially those in the end (like me). But time will be faster than ever during a workout, and before you know it, you're done. And you will feel as if you have done something amazing. What they have.
Let Dixon summarize: "Tabata training will make you fit in less time." Amen, sister.