Should I do fewer reps with heavier weights or more reps with lighter ones?
It’s your choice. A recent study from the Journal of Applied Physiology found that people who did 20 to 25 reps of an exercise with lighter weights had the same strength gains as people who did only eight to 12 reps with heavier ones. Whichever weights you pick up during your fitness routine, the key is to work to the point where you couldn’t do another good rep if you tried, says study author Rob Morton of McMaster University in Hamilton, Ontario.

Are the calorie readouts on fitness exercise machines accurate?
Don’t plan your meals around them. ‘We all burn calories at different rates, and machines don’t take into account that some people move more efficiently and burn fewer calories,” says Carol Torgan, Ph.D., an exercise physiologist in Bethesda, MD. If you’re really into numbers, use the readout to compare today’s fitness workout with your last one. “Challenge yourself to either increase the number or reach the same target faster,” she says.

How often do you need to change your fitness routine?
Switch your fitness routine up about every month if you workout two or three times a week. One of your body’s extraordinary powers is that it gets better at any activity the more you do it. The downside: You’ll burn fewer calories. Megan Dahlman, the Dahlman Elite Training Systems owner in Newberg, OR, suggests making a change every few weeks to keep the burn going. Do the activity longer or harder (add hills or intervals if you’re walking, for instance), tackle an extra day a week, or try something altogether new.

What do you need to eat during a fitness workout?
Not as often as the overstuffed energy bar isle would make you think. The only time you need to add calories during your fitness workout is if you’re working out for significantly more than an hour; that’s when your body’s reserve fuel sources can use a fill-up (a couple of bites of an energy bar or a few sips of a sports drink in addition to water) so you can keep going stronger without fading.

BIG BULGING MUSCLES?
Won’t happen! Most women don’t have the right hormones to build bulk. Those how do pile on muscle are very rare – and work extremely hard to get there.
The information above is not intended as individualized medical advice. You should always consult with your own doctor about your medical condition.
Further Reading