20 years ago, I was one of those who loved doing back to back classes. Heck, I think my max was 5 classes in a day. I'd travel from Orchard to Raffles Place to Suntec City all in a day to get all the classes in. BODYCOMBAT™ was my thing. So yes, I understand why people love doing back to back classes or more than 2 classes a day. The love of the program, the high I got, the people in the classes I was with. Those were contributing factors that amped up my desire to attend as many classes in a day as I can.
20 years later, now that I've gotten a lot more knowledge and experience in me, I raise my eyebrows whenever someone tells me they want to do more than 2 classes a day. It would seem hypocritical of me to say anything, since I did those myself 20 years ago. But with music at a faster pace, movements being way more complex, and scientific evidence released through the years, I find it appropriate to call out what shouldn't be done for the good of the members who come to my classes.
Science tells us that if you workout for more than 45 minutes at one go, your body will release a higher concentration of cortisol which can cause muscle breakdown, reduce protein synthesis and can actually cause you to gain abdominal fat. If you don't get enough rest or have proper nutrition, the increased level of cortisol can remain elevated and that can cause prolonged muscle soreness, insomnia, mood swings, lowered immune system and even problems with memory function. If you're training to be an endurance athlete, that's a whole different story. But if you're like me, exercising for general health benefits, then we need to consider the time spent in the gym.
1 hour of workout, including warm up and cool down, is really all you need. Giving your 100% within that one hour will help you reap all the benefits of the workout. You don't need to do 2 classes in a row. Heck, I call whoever who tells me they give 100% in their back to back classes a liar. The perceived effort may be 100%, but it never is. And you'll possibly be reaping only 25% of the benefits, which can easily be cancelled out by the elevated amounts of cortisol. Is it worth the while then?