This Is Why You Don't Go to the Gym

We can't keep our own fitness promises for the same reason that addicts are addicts and Congress can't pass deficit reduction

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Every January, millions of Americans, brimming with optimism and a little extra belly from the holidays, commemorate the new year by making an unfamiliar urban trek. They go to the gym.

One in eight new members join their fitness club in January, and many gyms see a traffic surge of 30 to 50 percent in the first few weeks of the year. Stop by your local gym today, and the ellipticals will be flush with flush new faces. But next thing you know, it will be April, our gym cards will be mocking us from our wallets, and our tummies will have sprouted, on cue with the tree buds.

Economists make and break gym promises just like the rest of us. And, as they're considerably more likely to run statistical regressions on their personal lives, there's a healthy academic literature about going to the gym. Here's what economics can teach us about fitness and the fitness industry.


People are way too optimistic about their willpower to work out, Stefano Dellavigna and Ulrike Malmendier concluded in their famous paper "Paying Not to Go to the Gym." In the study, members were offered a $10-per-visit package or a monthly contract worth $70. More chose the monthly contract and only went to the gym four times a month. As a result, they paid 70 percent more per visit than they would have under the plan they rejected. Why? Because people are too optimistic that they can become gym rats, which would make the monthly package "worth it." Silly them.

You might call this behavior "laziness." Economists prefer "hyperbolic discounting." This is the theory that we pay more attention to our short-term well-being and "discount" rewards that might come further down the road. Think of a small reward in the distant future, like taking a nap three weeks from now. Doesn't hold much appeal, does it? But when the small reward is imminent -- Take a nap right now? Woo hoo! -- it's considerably more attractive. Given the choice between small/soon rewards versus larger/later benefits, we'll take the former. Hyperbolic discounting helps to explain why Congress can't pass deficit reduction, why drug addicts stay addicts, why debtors don't pay off their bills, and why you keep telling yourself that the right day for exercise is always "tomorrow."

The other problem with sustaining the motivation to work out is that ... well, motivation is exhausting! According to the theory of decision fatigue, the simple act of making any decision depletes us of a limited store of willpower. Exercise isn't just an investment of time, it's also a choice -- and a difficult, even exhausting choice for people whose daily habits don't involve running and lifting.


Think about what you're paying for at the gym. The machines, the free weights, the televisions, the shower. But aren't you also investing in motivation? A membership is different from a one-time purchase. It's also a promise that you expect your future self to uphold. But too often, a membership isn't enough to keep us at the gym. Maybe the nudge we need is just ... money.

A 2009 study out of the University of California-Santa Barbara reached the unsurprising conclusion that people are more likely to work out when rewarded with cash. Go to the gym once, and the results can be hard to see. Collect a check at the gym, and the results are in your pocket. But let's assume you can't find somebody to pay you to work out (a likely assumption). The solution is to find somebody to tax you for not working out.

Recently, a couple of Harvard graduates launched a program called Gym Pact based on the simple principle that if skipping the gym is a broken contract with ourselves, we ought to pay a penalty for slacking. So Gym Pact charges your credit card a penalty of at least $5 if you fall short of your work-out goal each week.

"If there's a cavity, you know it needs to get filled in, but if it doesn't hurt right now, you may not bother,'' one of the founders told the Boston Globe. "In traditional gym memberships, not going is not very costly. In this one, you actually might feel the pain of not going immediately.''

That's a fine idea to get people to spend more time at the gym. Too bad your gym has different plans.


Gyms make most of their money from two sorts of people: 1) Absentee members and 2) super-users who pay not only the monthly fee but also for the add-ons, like trainers and classes, all the way down to the whey smoothies.

"Commercial health clubs need about 10 times as many members as their facilities can handle, so designing them for athletes, or even aspiring athletes, makes no sense," Men's Journal explained in Everything You Know About Fitness Is a Lie. One way to build a financially efficient gym is to make it appear really financially inefficient for gym rats:

The winning marketing strategy, according to Recreation Management Magazine, a health club-industry trade rag, focuses strictly on luring in the "out-of-shape public," meaning all of those people whose doctors have told them. The entire gym, from soup to nuts, has been designed around getting suckers to sign up, and then getting them mildly, vaguely exercised every once in a long while, and then getting them out the door.

Now is the winter of our idleness. In January, our cup of willpower overfloweth. But by June, the odds that you've kept your New Year's Resolutions falls to under 40 percent. On the bright side, your flabby willpower means open weight machines for other gym members. Our laziness isn't good for our fitness, but it just might be good news for the fitness industry.