Ignore fat-burning zone charts at the gym. Some simple math and a heart-rate monitor is all you need to accurately work yours out, according to an expert.

• Generic charts showing an optimal heart rate for fat-burning aren't accurate, research suggests.
• You can calculate yours more accurately with a heart rate monitor, an expert said.

Generic fat-burning zone charts at the gym are not accurate and you can calculate your own with a heart-rate monitor and some simple math, according to an expert.

The fat-burning zone refers to the optimal heart rate for shedding the most fat while you exercise. The charts that you find in the gym typically suggest an ideal heart rate range for this, often varying depending on your age group.

Insider previously reported on research that found that target heart rate zones rarely predict how much fat people burn while working out and, instead, calculating your own individual fat-burning zone is more likely to lead to results.

Isaac A. Chávez-Guevara, a lecturer in the Department of Health Sciences at the Autonomous University of Ciudad Juárez, Mexico, and a fat-burning researcher, told The Washington Post in article published on Wednesday that many people exercise more intensely than they need to to burn fat. He explained how you can find your personalized fat-burning zone.

How to find your fat-burning zone

First, you need to figure out your maximum heart rate, he said. You can do this by wearing a heart rate monitor or smartwatch and walking or jogging on a treadmill at an easy pace. Keep increasing the pace every three to five minutes until it feels "quite draining" and your heart rate plateaus. This is a good estimate of your maximum heart rate.

Once you have that figure, calculate 60% of it, he said. A simple way of doing this is by multiplying it by 0.6. This is the heart rate you should aim for when working out if you are looking to burn fat, he said.

In a new review, Chávez-Guevara and his research team reviewed data from 64 studies involving 7,500 obese people and found that those who worked out at between 57 and 66% of their maximum heart rates burned the most fat.

"You do need to keep moving for more than a few minutes at that pace to burn a meaningful amount of fat," he said.

Strength training and diet are keys to weight loss

The type of exercise you do could also affect how much fat you burn.

While cardio is often associated with losing weight, research has found that strength training or lifting weights can be just as effective, or even more so in the long term, as it helps you build muscle, rather than just burning calories, which boosts your metabolism over time.

However, some experts say that diet might be even more important than hitting the gym for weight loss. And this makes sense, as to lose weight you have to be in a small calorie deficit i.e burning more calories than you are consuming, according to dietitians.

But this doesn't mean cutting out all the foods you love. Insider's Rachel Hosie, who follows the 80/20 rule, previously shared 11 high-protein recipes that make losing fat and gaining muscle easy.