The question was raised by David Blaine who, among many other feats, set a Guinness record for staying under water without an oxygen supply for over 17 minutes. Based on his exploits, he believed that willpower is a muscle that can be strengthened.
Willpower, by Roy Baumeister and John Tierney, is the best book I’ve read on the subject. It was published just a few weeks before I finished Fitness Beyond 50: Turn Back the Clock, so I have minimal reference to it in my book, but one study the authors cite is particularly interesting.
I hope that no one reading this has ever has to go to prison, but if you ever come up for parole, try to appear before the parole board in the morning. Psychologists studied the records of over 1,000 prisoners who were up for parole and found that the time of day was a factor in determining the chance of each prisoner. Those who went before the board early in the day had a 65 percent chance of being paroled, while those in the afternoon won less than 10 percent of the time.
Here’s why: Exercising willpower requires energy, which is supplied by food that’s converted into glucose. As their supply of energy and willpower diminished, members of the parole board most often opted for the “safe choice,” at least from their point of view – parole denied.
We all begin each day with some amount of willpower and deplete it over the course of that day, the rate dependent upon the quantity and complexity of our decision making. The greater the number of decisions, the sooner our supply disappears.
If you plan to start and stick with a program of fitness and healthy eating, a word of advice: Exercise in the morning. If you can’t work out early, at least make the commitment and take steps to ensure that you will do it later (pack your gym bag; set aside a specific time; etc). Apply the same discipline to your decisions about what to eat and not eat. An example: “I won’t eat French fries with my sandwich at lunch; I’ll order a salad instead.”
Is willpower a muscle that can be strengthened? I think so. The more we make decisions that favorably impact our lives, the more likely it is that we’ll adhere to that practice in the future.