Drop up to 10 pounds a month by going to these Atlanta fitness classes every week

Aerobic exercise is good for your body and your brain.

Aerobic exercise is good for your body and your brain.

It's tricky to measure fitness by the number you see on a scale, but once you've determined a healthy goal weight, what are the best means of reaching it quickly? About 80 percent of your health and fitness revolves around your diet, but what you do with the other 20 percent can definitely be a swift kick in the right direction.

According to personal trainer Jeff Smith, intensity beats duration when it comes to exercise. That's why high-intensity interval training (HIIT) is one of the best fitness routines to encourage weight loss in the body. Check out these Atlanta HIIT classes a few times a week for a boost in your fitness routine that just might reveal itself on the scale.

Midtown and Sandy Springs locations. theblastlife.com

This Atlanta-born fitness program rotates between treadmills and weight training for a workout that targets your whole body and keeps the calorie burning going long after you hit the showers. While the classes are quite a blast themselves, the moniker comes from an acronym: "Balanced Level of Aerobic/Anaerobic and Strength Training." The bonus? All of BLAST's instructors are trained to make modifications for injuries or issues, so nothing has to hold you back from hitting the studio.

Midtown, Alpharetta and Inman Park locations. exhalespa.com

This nationally-loved chain of exercise studios kicks things up a notch for their Extreme classes, which involve students operating at max capacity for short periods of time. Plyometrics, burpees, weights and more await the brave fitness fiends who attend this high-intensity class, but the instructors are always welcoming and sure to encourage newbies to find a pace that works for them. The room is divided into stations, and while students generally rotate through all of the exercises twice in each class, there's enough variety to keep even the cockiest workout gurus on their toes.

3167 Peachtree Road, Atlanta. 470-553-0080. sculpthouse.com

One of the only studios in the nation to combine the strength-building elements of the pilates megaformer and the fat-burning benefits of the treadmill, Sculpthouse is winning fans all over the metro area for its CardioSculpt class. Unlike many treadmill classes, which can wreak havoc on the joints, Sculpthouse uses curved treadmills for its running intervals, providing a low-impact workout that doesn't lack intensity.

Buckhead and Poncey Highland locations. chaosconditioning.com

Led by instructor Jeff Baird, Chaos Conditioning uses a consistently rotating menu of high-intensity workouts arranged at stations in both locations of The Forum Athletic Center. Get your strength training fix alongside heart-pumping cardio for fitness fans of all levels. Watch time fly as you sweat your way through the welcoming, upbeat class: the circuit system keeps anything from feeling repetitive or boring.