I decided to gather some data. This is the information from a class I was teaching today in the morning. I used the Armour App with the Apple Watch as I believe is more accurate than what comes with the Apple Watch.
The class was Hot I was surprised to see the 686 calories but for me the heart rate at 176 was great since it takes me a long time to bring my heart rate up. The second chart shows the heart rate going up and down during the middle of the class.
I find that it looked similar to the interval training especially between the 20 min and the 65 min.
This will give an idea to the people working out in the gym or other types of workout and they have their data to compare, as to how the heart rate and for some the caloric aspect can become so interesting to observe and compare.