Fitness Files: No wonder shopping knocks me out

Rolled into garage, killed ignition, pulled brake.

Immobile, a human sandbag, I’m sunk into the driver’s seat.

My usual sprint from car to bathroom? Impossible.

My customary gathering up of packages, pulled through the passenger door for a squished exit between two cars? Too distressing to consider.

Minutes later, I’m dumped into my desk chair, slumped before the computer, devoid of will or wit to communicate.

Just spent a day shopping. Actually, half-day did me in.

Yes, I brag in my blog about a 21-mile run. Yet, walking the aisles of a department store exhausts me to the core, strangling some organ that running doesn’t touch.

Still facing the computer, I search Google for “mall fatigue.”

Author John Tierney shares in The New York Times Magazine of August 2011 an overflowing shopping bag full of studies on “decision fatigue.” Together, Shai Danziger of Ben-Gurion University and Stanford’s Jonathan Levay seem to demonstrate that a person “can’t make decision after decision without paying a biological price.”

The reason I’m exhausted? The brain is like a muscle, only instead of using up glycogen, the brain uses up glucose.

In a “real-world test of the theory,” researcher Jean Twenge, then at Florida State, went to the mall and interviewed shoppers, asking them to solve simple arithmetic problems.

“Shoppers who had already made the most decisions in the stores gave up the quickest on the math problems,” Twenge is quoted as saying. “[Showing that] when you shop til your drop, your willpower drops, too.”

I like to look back at man’s 200,000-year past to see why I’m biologically prepared to run distance but am unprepared to confront the millions of mall decisions needed for holiday shopping.

Tierney says, “In the rest of the animal kingdom, there aren’t a lot of protracted negotiations between predator and prey.”

So I’m better wired for the millisecond decision between eat or be eaten than for deciding whether my 6-year-old grandson will like the Bat Cave Transformer or whether it appeals only to a grandma? Not to mention whether it is worth the price and how soon would it be discarded into the archeological scrap heap of plastic?

Yeah, that bothers me. Really, I want to flee. Get out of the toy aisle display, a testament to future garbage.

But I persevere, haunted by the fear that the Bat Cave Transformer, once opened, will garner a look of disappointment, not excitement.

But I am so lucky.

Yes, I’m a tortured prisoner of decision fatigue, but I’ve got the means to buy all that detritus. Dean Spears, a Princeton economist, is quoted as saying, “Shopping can be especially tiring for the poor who struggle continually with trade-offs.”

They may have to weigh each gift purchase against rent, gas or food money. More exhausted by compromise than I, poor people are “much more likely to eat during a shopping trip … buying ready-to-eat snacks like Cinnabuns.”

Spears says that their problem isn’t low will power so much as brain-weary decision fatigue.

As you may have guessed, the placement of sweet snacks by cash registers is a marketing decision that speaks to every shopper’s decreased willpower from the accumulation of shopping judgments and compromises.

In Roy Baumeisters’ Florida State University lab, brain-exhausted subjects were fed sugary lemonade and lemonade with artificial sweetener. “Again and again, sugar restored willpower, while artificial sweetener had no effect,” he wrote. “The glucose will at least mitigate … depletions and sometimes … improve the quality of decisions.”

Who knew searching out the reasons for my shopping collapse would take me to the sociology of the poor or studies of brain chemistry?

Here’s my suggestion for a study. I’ve rehearsed distance running for years. I can handle miles others can’t. However, I avoid shopping, so I’ve never developed “shopping fitness.”

Tierney’s article seems to say shopping tires every human brain. Is there a researcher who’d like to explore whether my friends who shop all the time have a shopping endurance that I do not possess?

And it turns out the organ responsible for my collapse is the brain. Maybe my friends have already developed the strategy of replenishing brain glucose while shopping — munching a baggie of raisins and nuts, maybe.

If I pack healthy apple slices, maybe I won’t yearn to bolt from the store. I’ll make confident decisions and arrive home to zip into my garage with enough energy left to visit the ladies’ room and unload my packages.

Newport Beach resident CARRIE LUGER SLAYBACK is a retired teacher who, since turning 70, has ran the Los Angeles Marathon, placing first in her age group twice.