No matter which type of Yoga you do it doesn’t work your muscles and body the same as traditional resistance and cardio training. There is no denying that yoga is an amazing way to gain flexibility, strength and mental clarity. But as yoga is becoming more and more mainstream, many are substituting a 60-minute yoga class for conventional resistance training and cardio.

Bikram yoga, also called Hot Yoga, a form of yoga performed in a room heated to above 100 degrees, is especially popular. But is it an effective substitution? Can a hot yoga class take the place of the gym?

On average, a 150-pound woman will burn over 400 calories each hour during hot yoga, compared to over 600 calories the same woman would burn running a treadmill over the same period at an 11-minute-mile pace.

However, some of the calorie burn during hot yoga is due to the body working so hard to keep itself cool. During hot yoga, the heart rate does increase, but that doesn’t mean there’s a higher physical demand on your body. Simply put, a hot room does not make for a more intense workout.

One could expect to see a one- to three-pound weight loss during a hot yoga class, but this is purely water weight, and will return when you rehydrate. No extra calories or fat have been burned. You are just sweating because you are hot.

But is yoga, heated or not, a sufficient workout? Strength and Endurance yoga which are challenging, will put enough stress on the muscles for them to grow stronger. Other gentler forms work your flexibility and mental focus, which we all need.

Your muscles, however, must be worked through their full range of motion, against resistance, a minimum of two times a week to properly develop. Yoga, of any kind, just doesn’t provide that.

Yoga is a great complement to any fitness routine, But it shouldn’t replace a full fitness regimen.