6. Watching TV or Reading.

"People tend to get on cardio equipment and think they're paying the piper, but they're so into their book they're wasting precious caloric time," says Pillarella.
The bottom line is that when you're focused on other things, your workout suffers, she says.
You can walk at a 4 mph pace for 45 minutes and burn 300 to 400 calories, says Pillarella. But you could get the same calorie burn in 20 to 25 minutes doing intervals (running or walking as fast as you can for a minute or two) every 90 seconds.
"It's the total number of calories burned that counts," she says.
If you need a diversion to make it through your session on the elliptical machine, try music, suggests Comana. Invigorate your workout with a fresh mix on your iPod instead of spending your time staring at the crawl on Fox News.
"Music can inspire you to pick up the tempo," Comana says