What is the difference as far as intensity goes between clamping and hanging? I ask this because I'm just starting out with clamping and everything I've read about it says to clamp for no more than 20 minutes per day for the first six months. I had been hanging for well over a year and I used to do it for 3-4 hours per day. At the beginning I started hanging at about 45 minutes per day. Is clamping really so intense that an hour per day would be for a seasoned veteran?