Watch it all.
I think that is probably about right, although most athletes will take 10 years to become world class rather than the five this man has set himself. It is important to also pace yourself so that your body has time to adapt to the changes in physique necessary and for new learning and neural pathways to develop and reinforce themselves without the dangers of injury, over-training and it has to be said mental exhaustion and rebellion.
But most of us do not have the determination and the ambition to set ourselves the goal of doing one thing excellently rather than several things moderately well. I never got there, though for some years I did try as a young sportsman and put in the hours and hours, until injury put paid to it.
But what is it that can refresh and drive you on? Him who renews your strength.