You can't get a runner's high in tennis, but you can get in the zone or close to it.
Tennis has bigger highs and lower lows than running. Many of the things that make running beneficial can hurt your tennis game. For example, letting your mind wander during a run is very calming. In a tennis match, you will lose the point if your mind has wandered off to what you're going to eat when you go off the court, or where you're going afterwards, or any number of benign or even self-destructive thoughts.
My highest high during a United States Tennis Association (USTA) league match occured in August, 2003, when I competed along with my team in the regional district championships, held that year in Portland, Maine. I still needed one more round of chemotherapy and my stem cell transplant. I had a fungal pneumonia which was being kept in check with an anti-fungal drug; lung surgery, the only way to get rid of it, was scheduled for later in the month after my platelet count had risen enough to stem bleeding during surgery.
Still, I felt well enough to play, and my doctors had given me permission. Out on the court with my partner, Donna Young, I was free from the pressure to win because I had no expectations other than being able to hit the ball and enjoy being out of the hospital and on the court. I had so much fun that I forgot to fret in my normal fashion. We got in the zone, and won the match 7-5, 7-5. On the court there were just the two of us playing, but it really was a team effort.
The lows can be something else, especially if you are as prone to obsessing as I am. Years before at another District competition in Providence, R.I., Donna and I had been ahead 5-2 in the third and decisive set. The other team crept up on us, one game at a time, and we panicked and tensed. Instead of playing our regular game, we played not to lose. Lose we did, and we spent the rest of the weekend, and actually weeks after that, hating ourselves and analyzing where we went wrong.
I've been re-reading Ian McEwan's novel "Atonement" in advance of seeing the movie, and I remembered a chapter from his novel "Saturday" in which he described his main character's thought process during a squash game. That chapter really resonated with me for the way in which a game, which is supposed to be fun, can assume out-sized proportions. Henry, a successful neurosurgeon, is losing to his opponent, Jay, another doctor:
"The constant change of direction tires him as much as his gathering self-hatred. Why has he volunteered for, even anticipated with pleasure, this humiliation, this torture? It's at moments like these in a game that the essentials of his character are exposed: narrow, ineffectual, stupid -- and morally so. The game becomes an extended metaphor of character defect."
I also recently reread Timothy Gallwey's book "The Inner Game of Tennis," in which talks a lot about the zone. He writes that when a tennis player is "in the zone," "He's not trying to hit the ball, and after the shot he doesn't think about how badly or how well he made conact. The ball seems to get hit through a process which doesn't require thought." He likens it to peak experieces in which people feel at one with the experience and, in the words of psychologist Abraham Maslow, "free of blocks, inhibitions, cautions, fears, doubts, controls, reservations, self-criticisms, brakes." He quotes Phil Jackson, coach of the Chicago Bulls, describing "the zone" in his book, "Sacred Hoops": The secret is not thinking. That doesn't mean being stupid; it means quieting the endless jabbering of thoughts so that your body can do instinctively what it's been trained to do without the mind getting the way."
Gallwey offers suggestions for stopping the mental chatter. First, it boils down to changing your definition of a good match from one in which you have to win, to one in which you played great and had a good time, no matter what the results. (Yeah, yeah, yeah, easier said than done.) He also offers useful techniques along the lines of others who counsel the benefits of mindfulness.
Breathe. Focus. Be aware of the present. Keep your eye on the ball.
In tennis as in life.