Exercising judgment: The psychology of fitness

The participants who had used up their self-control by avoiding the cookies and chocolates were less determined to finish the impossible anagrams.

“People are aware that they are sometimes vulnerable to saying the wrong thing, eating the wrong thing, or doing the wrong thing, but they may be unaware of their own self-regulatory capacity at any given time,” Segerstrom and Solberg Nes write.

Baumeister says he doesn’t know how far the muscle analogy goes for self-control. He says his team hasn’t pushed anyone to the state of self-control exhaustion in the laboratory. But it appears that people begin to conserve their self-control as they approach exhaustion in the same way they would if they were getting physically tired. Plus, people seem to be able to exert self-control despite depletion if the stakes are high enough (like great athletes are able to do so even when they’re exhausted).

There is even research suggesting that glucose depletion is related to depletion of self-control, much like a muscle. And, also similar to a muscle, research has shown that focusing on a task that requires self-control — exercising or managing your money, for example — improves other self-control-related tasks, such as cutting down on smoking and drinking or helping out with household chores.

“These peripheral improvements suggest that you’re strengthening a core muscle rather than just working on the behavior,” Baumeister says.

Recently, they have done work to test whether, like a muscle, you can exercise your self-control to make it stronger. They gave students a variety of self-control tasks to do every day — sit up and stand up straight whenever you think of it; do all minor activities, such as brushing your teeth, lifting a cup to your mouth, and using a computer mouse with your non-dominant hand; don’t swear — and then they tested the students’ progress on self-control tasks. Their results have been mixed so far. Many participants have been able to improve their self-control, but some have not. Baumeister says the results are promising, but it still needs more study.

“This has not only theoretical interest, but also practical,” Baumeister says. “If we can actually make people stronger, then that would be a good, useful finding.” And it might help you work up the strength to get off the couch.

Once you’re off the couch, you have to figure out how to exercise to best meet your goals. That’s what Thomas Plante has been working on for more than 20 years. Plante, a psychology professor at Santa Clara University, has looked at the psychological benefits of exercise in men and women. He focuses on keeping the exercise constant — 20 minutes at about 70 percent of the participants’ maximum heart rate — and then he measures people’s mood.