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NO TIME TO HIT THE GYM? No worries: Recent studies have found that when it comes to exercise, intensity matters more than duration. Even if you have just 15 minutes to spare, you can still squeeze in an effective workout pretty much anywhere that's convenient—the office, the airport or your kitchen.

Find the Right App for You

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For these on-the-fly sessions, a smartphone loaded with the right apps can be a highly efficient personal trainer—and a handy one, too. Firing up an app is far less trouble than loading a video on your computer or television.
There are countless fitness-oriented apps available, but the vast majority are crudely designed, hard to follow and uninspiring. Plus, it can take forever to wander through the app marketplace and weed out the wimpier efforts—time that could be put to better use toning your thighs or strengthening your core.
We did the hard work for you, picking the best apps for tuning up your body (or turning off your brain) in almost no time at all, and organized them in an easy-to-follow chart. Now all you have to do is get moving, however briefly.