You're pulling 4-5G for a lot of the corners around the lap. We build up lactic acid because there are a lot of vibrations in the car and you have to have strong legs to hit the brake pedal. We need to be fit to do every lap at 100%.
I used to be a Catholic. I left because I object to conversion by concussion. If you don't agree with what they teach you get clobbered over the head until you do. All that does is change the shape of the head.