To lose weight, you should be ramping up your intensity when you exercise, according to fitness experts, but how do you know that you're exercising hard enough?
If you take a subjective measure of your intensity, you're relying on your own judgment of whether you're exercising hard. Studies show that your perceived exertion correlates well with your heart rate. So if you think you're working hard -- your breathing is deep and rapid, you break out in a sweat after a few minutes of activity, and you can't keep up a conversation -- you probably are.
But if you're a goal-oriented exerciser, heart rate monitors may be the way to go. In fact, Brooklyn-based trainer and nutritionist Michael Feigin says "without a doubt" heart rate monitors are critical for goals-oriented fitness: "Otherwise, the workout is a crapshoot."
"If you want specific results, you have to work specifically," he says. "One reason people become so frustrated is because they don't work specifically. They throw everything they have into the workout, and end up depleted."
Trainer Alex Fell, owner of Warrior Fitness Boot Camp with Ruben Belliard, adds that it's an individual's choice and says the average person can generally rely on the perceived exertion scale. But he encourages people with special medical conditions and competitive athletes to use a heart rate monitor.
Here's how to arrive at the right number for your heart rate monitor:
First, figure out your maximum heart rate: Subtract your age from 220.
Then, multiply that number by one of the following percentages, depending on what you're aiming for: