Here, she explains how to tackle this.

What To Eat

First, if you’re trying to shed pounds in general, you should aim to take in fewer calories than you’re expending overall (not just via exercise). This varies on an individual level, but you can use an app like MyFitnessPal to keep track of your cal input and calculate your basal metabolic rate (the calories you burn if you literally do nothing but breathe) here. Then, of the calories you are taking in, group them according to macronutrients: carbohydrates, proteins, and fat, says Simmons. (Hit the reset button—and burn fat like crazy with The Body Clock Diet!)

RELATED: 5 Signs Your Hormones Are Making You Gain Belly Fat

She suggests allotting about half of your daily calories to carbohydrates, such as whole-grain pasta and veggies like potatoes, corn, and peas. Another 20 to 30 percent should be made up of protein-rich foods such as chicken, eggs, spinach, and beans. And the remaining 20 to 30 percent goes towards fat—yes, fat. Opt for healthy sources, such as nuts and olive oil, says Simmons. And don’t overdo it on that avocado: One gram of fat contains nine calories, more than carbs and proteins at four cals per gram.

Check out some of the weirdest things people have done to lose weight.

What To Do At The Gym

The best workout to burn fat is strength-training. (You probably guessed that, huh?) “Increasing muscle mass is going to help increase your metabolism,” says Simmons. That means you’ll be burning more calories overall. Focus on working the largest and most powerful muscle groups to burn the most calories possible. Those muscles include your glutes and quads. You can work those powerhouses with moves like squats, lunges, chest press, and rows. She recommends working one of those groups per day.

RELATED:  5 Ways to Eliminate Back Fat

When it comes to your armpits, the two groups to focus on are your chest and back. For your chest, try moves like pullups, chinups, and cable pulldowns. For your back: bench press, chest fly, pushups, and shoulder press. Simmons recommends waiting a day or two before working your chest and/or back again so your muscles have time to repair and rebuild.

And don’t be afraid to lift heavy. Simmons says the best way to burn fat and get your heart rate up is lifting a heavier weight for a moderate amount of reps. Her strategy: Choose a weight that you can only complete eight to 12 reps with proper form. If you can’t maintain form, it’s too heavy. If you’re losing count of the reps you can do with a weight, it’s probably too light.

And if you’re thinking, “what about cardio?” Simmons says it’s best if you choose high-intensity cardio exercises like interval training or bootcamp classes, rather than running on a treadmill at the same pace for 30 minutes.

The bottom line: You can’t spot reduce your armpit fat, but you can work towards getting fitter overall, which could have an effect on that area.