Absolutely individually. However, it needs to attach to your own daily cycles, because the working capacity and the mental concentration have different max level during the day and night. For example, I can successfully train at night from midnight to 6-7 am. Then within 3-4 hours I have a strange period: it is difficult to concentrate on the performance of movements and the power indicators are somewhat falling. From noon to 16-17 pm I'm fully prepared for training. Then again follows 3 hour interval of lowering my condition. And, further, I'm ready for training all the evening and night til the morning. I'm sure that each of the guys who are hard at training know their own most "active" hours during the day. All this, as I told, individually.