His wife called him crazy. Most sports nutritionists would have, too. Just to prove he could do it, Joe D'Amico trained for his 15th marathon, the Los Angeles Marathon, eating a McDonald's-only diet.
Not only did the self-dubbed "McRunner" cross the finish line among the top 30 marathoners, he ran a personal best time of two hours, 36 minutes and 14 seconds.
While others might be astonished by his enviable, fast food-fuelled finish earlier this year, Mr. D'Amico, who is not sponsored by the restaurant chain, says he's not surprised.
"The fact is I had put in a lot of really solid training," he said by phone from his Chicago area home, noting he ran an average of 100 miles, about 160 kilometres, a week in preparation for the race. "I'm a firm believer in mileage."
Although his intake wasn't exclusively Big Macs, French fries and Quarter Pounders with cheese (he also ate many Yogurt Parfaits, salads, Egg McMuffins and Chicken Snack Wraps), Mr. D'Amico's heavily processed meal plan provides plenty of food for thought as to what makes an optimal marathon diet.
Many professional athletes take great pains to fine-tune their diets. Wimbledon champion Novak Djokovic, for instance, famously credits his transformation from tennis great to tennis god this season to a gluten-free regimen. No pasta, no bagels, no pizza.
Robby Ketchell, the director of sport science for the Tour de France's Team Garmin-Cervelo told Esquire magazine this month his leading cyclist Thor Hushovd eats 250 to 300 calories per hour while racing, and relies on the team's travelling chef to prepare lean proteins, fruits and veggies and "clean carbohydrates," to ensure peak performance. Canadian professional Ironman triathlete Brendan Brazier swears by a nutrient-dense, vegan diet.
But then, there are other sports stars like Australian cycling Olympian Ryan Bayley, who is arguably as well known for his penchant for fried chicken, ice cream and burgers as he is for his record-breaking dual gold medals in Athens. U.S. running champ Bill Rodgers, who set a Boston Marathon record of 2:09:55 in 1975 and again at 2:09:27 in 1979, was a legendary junk-food junkie, known to indulge in copious amounts of cookies, potato chips and post-run gin and tonics.
So just how much does your athletic performance depend on what you eat?
Mark Haub, associate professor in the department of human nutrition at Kansas State University, suggests the answer is not as straightforward as you might expect.
Dr. Haub, a former marathon runner, is perhaps better known in the media as the "Twinkie diet" professor. Late last year, he embarked on a 10-week diet, based on convenience snacks like Hostess cakes, Oreos and Doritos chips. He lost an astounding 27 pounds in the process.
Instead of normal meals, he ate a sugary snack every three hours and limited his calorie intake to less than 1,800 a day. To supplement the diet, he took multivitamins, protein shakes and a minimal quantity of vegetables.
"Why do we need to eat certain things if we come out as healthy?" he said by phone. If, for instance, an individual is tested to have high bone density and regularly takes in an adequate level of calcium, he wonders, does she really need to include milk in her diet, as conventional wisdom dictates?
When it comes to running a marathon, he says, there's no doubt runners need to make sure they are properly nourished and have enough fuel in the tank, or else they risk hitting the wall or, as it's commonly called, "bonking."
But he's not convinced it matters what formthat fuel takes - whether they eat a Hostess Ho Ho and an antioxidant supplement, or a whole-wheat bagel with strawberries.
"Does it matter? And as I understand it now, I'm going to say no," he says. "Athletes may have greater needs for certain vitamins, minerals, macronutrients than non-athletes. And as long as they get those, I haven't seen much data ... that it would indicate it matters from a performance perspective too much."
Mr. D'Amico appears to have supported this thinking with his McDonald's challenge. Even though he wasn't eating his regular training diet of whole-grain cereals, vegetables, turkey sandwiches and pastas, the number of calories he ingested daily from McDonald's remained at aconstant 3,200, and he tended to eat the same amount of macronutrients.
After analyzing his food log, he discovered he had maintained his carbohydrate intake at around 65 per cent. He determined what and how much to eat, purely based on how he felt, and experienced no dip in energy or strength. The 6-foot runner even lost weight, from 142 to 137 lb. And most importantly, he says, he realized he didn't have to be anxious about what he ate.
"I definitely see that in some marathoners and runners around me - they're searching for the perfect food for the perfect timing when you eat it, the perfect portion," he says. "I don't think perfect's out there. I think a lot of us drive ourselves batty. We have to have FRS [energy drink]or Gatorade. There's no magic in that."
Toronto registered dietitian Mary Bamford, however, subscribes to the more conventional sports nutrition mantra that, while no amount of good nutrition will make an average athlete elite, a poor dietcan make an elite athlete average. So a "clean" regimenof lean proteins, whole grains, fruits and vegetables won't necessarily shave minutes off your time, but a high-sodium, artery-clogging diet could potentially end up slowing you down, she says.
"If I took a Mercedes and put high-performance fuel in there, I know that car is going to work very well for a very long time," Ms. Bamford says. "If I start putting in the lowest-grade gas in ... it'll work fine for a couple months, but the engine's going to start knocking after a while."
Likewise, the body can compensate for a junk food diet for a while, she says. "But is it going to perform at its best? Will it feel its best? Not so much."
The marathon diet
While other runners were taking care to nourish themselves with whole grains, skinless chicken breasts, steamed vegetables and protein shakes in the last 30 days before the L.A. Marathon in March, Joe D'Amico, a.k.a. "McRunner," restricted his diet to what he could order off a McDonald's menu. (His exceptions were non-McDonald's water, energy gels, multivitamins and ibuprofen.)
Mr. D'Amico estimates he ingested about 3,200 calories a day, roughly the same amount as during previous training programs. (Some elite marathoners have been known to consume as many as 5,000 calories a day while training.) Below is a sample of what Mr. D'Amico recorded eating on his blog for Day 26 of his month-long challenge:
Morning: Egg McMuffin (with egg only), egg & bagel sandwich and a small orange juice.
Afternoon: Two hamburgers, no pickle, a "bucket" of Coke and a small Shamrock-chocolate shake.
Evening: Three-piece Chicken Selects (crispy breast strips) with three honey packets and plain oatmeal.
Snacks: Two packs of granola.