A typical day during the summer before my 2019 season was almost entirely training. It would start early, have a few breaks when needed for meals, bathroom, and air, and then it would end late. Afterwards I always spent time with friends before calling it for the day and going back home. I also played many matches with friends of mine that were mostly better than me at tennis so I could improve faster and become a more competitve player and a better leader for the tennis team. Below is an example of how an average day of training, in a week with no matches, would go.
The days seem long in the list but it was always fun because most the training was spent with people that I got to make friends with from other schools, cities, states, etc... and I rapidly became a better player. All of this work pays off in more ways than one as well. I noticed that during these long days, even after hours of working out, I started thinking clearer and faster as well. I believe that exercising even to a lesser extent than this definitely helps not only the body, but the mind as well.