“A lot of elite coaching is box ticking.” Stated Nick Weal when he and Martin Weston presented at the National Coaches Conference back in 2016. Their presentation included on court demonstrations and insight into the national training camps which they run at the NTC.
Jarrod Egan, former strength and conditioning coach at the LTA says most professionals average four hours of tennis a day. "Generally most players spend four hours a day playing tennis in training. This is split up into a two-hour block in the morning and a two hour block in the afternoon – meaning if they want additional strength or conditioning work they have to squeeze it in-between blocks."
Focusing too heavily on one aspect of a players game could mean neglecting other elements. Avoiding this is where the box ticking comes in, players will have a fairly standard hitting session every day where they can go through the motions and make sure all bases are covered. No real coaching takes place here, more just reinforcing good habits or making minor adjustments. The second session is generally more specific to the players needs.
This fairly unique video of Maria Sakkari gives us some insight into what a hitting session looks like for professional players. For me the most interesting thing here is how the coach changes the focus slightly when he wants Maria to warm up a different type of shot. At one point he wants her to hit more spin to the backhand and at another the focus is on the taking the ball earlier and leaning into the shot. This is box ticking in disguise, he is cleverly getting Maria to practice a variety of shots without changing the drill or slowing down the session.
The last thing is that he consistently encourages her to accelerate and be loose with her shots. When warming up or practicing in general it's much better to hit freely rather than just making balls. You get more of a feel for the spin, it helps to form the full shot by encouraging the racket to follow through naturally and builds confidence for attacking shots. In this footage of Federer in a hitting session you can see just how relaxed he is and how much he accelerates in training.