How do I

You can put it under cardio and "add my own workout" - name it whatever you want, enter the time and calories burnt. It will not figure the calories for you this way. It's best if you have a heart rate monitor that tells you how many calories you burn. You could use a calorie calculator from any number of websites to figure what you burned as well.

I hear quite a few people put it in as circut training. The calories burned are quite close as they are using the JM formula. You can find the formula on Google.