i did a 5 week ULC experiment doing my normal bodybuilding routine the entire time.. what i found is after about 2-3 weeks it wasn't hard to work back up the same intensity in my training as before. I was able to put on 4lbs in that 5 weeks as well which is good for me as i don't put on weight that easily. But my issue was how I felt. I felt small which mentally is really hard to overcome for someone trying to improve their physique. In the end i feel I need that feeling of having your muscles full of glycogen to act as an extra motivator to keep pushing on.