THINK​FIT

If you're under 40, hold your stretches for 30 seconds. If you're over 40, hold them for 60 seconds. As you reach your 40s, your

muscles become less pliable, so they need to be stretched longer.

Exhale forcefully at the top of the movement when you do

abdominal crunches. It forces your abs to work harder

Keep your weight workouts under an hour. After 60 minutes, your body starts

producing more of the stress hormone cortisol, which can have a testosterone-blocking, muscle-wasting effect.

Count your repetitions

backward. When you near the end of the set, you'll think about how many you have left instead of how many you've done.

Shop forworkout shoes late in the day. That's when your feet are the largest. Make sure there's a half inch of space in front of your longest toe, and that you can easily wiggle your toes. Then slip off the shoes and compare them with your bare feet. If each shoe isn't obviously wider and longer than your foot, go half a size bigger.

Don't train with a weight belt. Over time, regular

training in a weight belt actually weakens your abdominal and lower-back muscles. Wear it only when attempting maximal lifts in such exercises as squats, deadlifts, and overhead presses.