Just because I know how to practice well doesn't mean that I practice well. Let me share a story of a session that was a perfect example. Interestingly, I had a conversation with Jerry before I started my practice session that should have given me the clues I needed to practice well, but I ignored them until it was too late.
It happened about a month ago, during the time I couldn't swing a golf club because of my shoulder. I had to do something to keep sane and active, so I was working on my tennis game.
I was trying to groove my groundstrokes to a new level, so I went and hit against the practice wall at the courts at the Rec Center where Jerry works.
The session went okay for a while. I was practicing my one-handed backhand, trying to hit with consistently good racquet preparation, working to generate reasonable power and, important for my development, topspin. (I tend to be very flat off the backhand side, and if I don't work on this the backhand will always be a struggle.)
I was hitting against the wall and in general I was trying to hit back to myself, shots that would be essentially down the line on court, so as to not have to move too much. I was trying as much as possible to make the need to react and move and set up my feet and center and breathe happen easily, so that I could focus on a good, well-prepared swing with a full swing-path. As the rallies would go on, the power would kind of ramp up, my control would get a little bit less, and I would find myself moving myself side-to-side, which was fun in its own way but ultimately led to more frequent errors. After a while the quality of my rallies started to decline, and I started to get a little frustrated. That was when I thought back to the conversation I'd had with Jerry before I started the session.
He had been talking about his Sunday racquetball game. He told me that during his last practice session he'd been "crushing" the ball (he was unsurprisingly pleased by that), and that during his match on Sunday he had been hitting similarly well--for a while, anyway. All of the sudden his shot quality disappeared and he started missing. For a while he couldn't figure out why and then he realized he was fatigued, so he wasn't getting the same movement and proper set-up and drive from his legs.
And then I was able to reflect that the day before I had played soccer for the first time since I injured myself, and though I was on the field for less than an hour, I hadn't played for three weeks and during that time had exercised very little. As a result, my fitness had dropped off somewhat, and so I was more fatigued than usual given the effort I'd put in. All of which pointed to this conclusion: maybe instead of ignoring it, I should actually feel the fatigue, and then break out of my obsessive must-hit-must-practice tendencies and, hey here's an idea, stop practicing, before the efficacy of the endeavor falls all the way to zero or below.
Makes sense, right?
Except what I did instead was practice serves for the next thirty or forty minutes. Will you be surprised when I tell you that it didn't go well, and I mostly missed and I got really frustrated and, instead of stopping, which is what I should have done, I kept hitting and kept hitting because I stubbornly didn't want to end in a bad string of serves. What finally got through this brick-like skull of mine was the realization that if I'm practicing while deeply fatigued I am essentially practicing to hit the ball badly, and that's not really likely to make me a better tennis player, is it?