The most effective metabolism-boosting treadmill trick doesn't even require pressing the power button. For Ryan's Make the Treadmill Beg Fat Blaster, you have to make the belt move by holding onto the bars for leverage and pushing as hard as you can. When you feel like you can't go any farther, turn on the treadmill for a 2-minute walk to bring your heart rate down, taking deep breaths to regain control. “This is the hardest of my routines because it's an interval strength workout,” she says. But when you torch about 425 calories in half an hour and keep your internal furnace stoked for long after you've stepped off the treadmill, it's more than worth it.