The Importance of Being a Furnace*


"If the furnace was hot enough, anything would burn, even Big Macs."

"And too, there were the questions: What did he eat?  Did he believe in isometrics?  Isotonics?  Ice and heat?  How about aerobic, est, ESP, STP?  What did he have to say about yoga, yogurt, Yogi Berra?  What was his pulse rate, his blood pressure, his time for the 100-yard dash?  What was the secret, they wanted to know; in a thousand different ways they wanted to know The Secret."

--John L. Parker, Jr.

It seems like I can't escape diets.  Everywhere I look I'm reading about people's diets.  My Facebook feed is full of pictures of what all my ultra running friends are eating.  In interviews, the elite runners I listen to are constantly being asked about their diets.

Why?  Part of it is the American obsession with diet, sure, but it's more than that.  As the sport gets more competitive, we're all looking for an edge; that's part of it too, the hope that we can find an advantage, the secret.  But there's another factor at play, too: it seems like people want to tell other people what they are eating, and why everyone else should eat that way too.  This may be due to the economics of ultra running, still in its infancy as a professional sport for some; sponsorships in many cases are tied to an athlete's social media profile, and all those bloggers need something to write about.  (Guilty as charged.)  And social media by its very nature encourages this sort of food-based voyeurism.  (Though maybe you should stop.)  But there seems to be a proselytizing aspect to it as well, particularly in the ultra world; not only to people want you to know what they're eating, but they  want you to know that you should be eating that way, too!

I'm reminded a bit of the minimalism craze of the late aughts, after Born to Run came out, and everyone wanted to tell you (rather loudly) why you, too, should be running in Vibrams.  The two cases share some similarities.  In both, there is a lot of research out there that can be conflicting and confusing, and the scientific community can't seem to reach a consensus.  Acolytes on all sides of each issue spout one-size-fits-all solutions.  And interestingly, both problems seem like they should have a universal solution.  I mean, shouldn't there be an ideal diet to optimize performance?  Shouldn't there be an ideal way to run, to minimize injury?

But the fact that so many people are finding success with so many different approaches would imply that there is no universal answer.  There are world-class athletes on paleo/LCHF/OFM diets (Zach Bitter, Jeff Browning, Tim Olson, Nikki Kimball);  on vegetarian diets (Sage Canaday, Scott Jurek, Mike Wardian); on vegan diets (Sandi Nypaver, Yassine Diboun); on gluten-free diets (Devon Yanko); on gluten-free AND vegan diets (Laura Kline, probably some hamsters); on all-fruit diets (Denis Mikhaylove, Mike Arnstein), and everything in between.  I think the common denominator is not what these people are eating, it's that they've all found what works for them.  There are arguments to be made for almost any diet.  We have enough trouble identifying what a healthy diet is for regular people, let alone defining what ultra-endurance athletes should be eating to maximize performance.  The more I read and hear, the more I think that the specifics of what you eat don't matter.  What matters is that you're paying attention to it.  If you are cognizant of what you're putting in your body, of what is does to you, of how it makes you feel and how it affects your performance, you're going to figure out what works for you.  And that's the secret.  That's where the advantage is.

Having said all that, here's what I've been eating.

This is not to say what you should be eating.  I may be a hypocrite, but I'm not going to go on a rant about people telling other people what to eat and then contradict myself two paragraphs later.  (You'll have to wait at least two, three posts for that.)  This is because since I've started to pay attention to my diet, at the beginning of last year, and have found something that, for now, works for me, people have been asking me about it.

At the start of 2015, I started following a low-carb, ketogenic diet.  (I hesitate to say "high fat," because I'm not sure that I'm actually getting the 60-70% of calories from fat that most "experts" would recommend.)  There were several factors in play when making this decision.  Primarily, I wanted to be more mindful of what I was eating, to help control my weight and to aid in performance.  I wasn't overweight by any stretch, but at 5'6", I was having trouble staying under 145 pounds, and wasn't anywhere near the 135-lb race weight from my collegiate days that I thought was most beneficial for my running.  I had done some reading and talked to several people who had experienced success with the diet, and the scientific theory behind it seemed, at least, plausible to me.    And, crucially, (and in contrast to calorie-counting, vegetarianism, fruitarianism, etc.), it seemed like something I could adhere to for an extended period of time.

My experience with the diet mirrored a lot of what I had heard and read.  At first, I felt pretty crummy and my running went in the toilet for about three weeks.  After that I started running normally.  I lost weight and was able to keep it off without starving myself.  And I found in races that my energy levels stayed much more stable, and I was much less prone to "bonking," despite taking in fewer calories than I had previously.

I mentioned it on the blog, and a few people were curious, but then I started running well, and people started to get really curious. ("What was the secret, they wanted to know...")  Some of the more common questions:

Why do you eat that way?  What's the theory behind it?
I've mentioned above why I started with this diet; click the link for a longer discussion of my own personal reasons for the switch.  The science behind a low-carb diet for athletes, which certainly in dispute, makes sense (to me at least) in theory.  For strenuous exercise, the body depends primarily on carbohydrates, and is most efficient at using carbohydrates as fuel.  You can burn fat, but if you eat a standard diet, probably not efficiently enough to use it as a primary fuel source, particularly in races.  Why does this matter?  Well, your body can store about 2000-2500 kcal of carbohydrate (in the form of glycogen).  At about 100 kcal/mile (about what it takes to run a mile, regardless of pace, believe it or not), that means you can go about 20-25 miles before depleting your glycogen and needing to replenish it.  For most exercise, this doesn't matter; you can run a marathon, or close to it, without worrying about taking in too many exogenous calories.  But for an ultra, you'll need a lot of calories, and getting those calories in can be a problem.

The theory behind a low-carb diet is that, over time, if deprived of carbohydrates, the body will actually become more efficient at burning fat--almost as efficient as it is at burning carbohydrates.  And the body stores way, way more calories as fat than it does as carbohydrates, like twenty times more.  The thinking is, if we can tap into those fat stores efficiently, we give the body an alternative fuel sources as races reach beyond the 2-3 hour mark, and decrease our reliance on taking calories in as we run.

Now, whether or not that's true is a matter of great debate.  (As is whether or not eating a low-carb diet is even necessary to become "fat-adapted" in the first place.)  But many athletes have anecdotally reported that they are able to run longer despite taking in fewer calories after switching to the diet.

What do you eat?
This is an easy one because it never really changes.  For breakfast, scrambled eggs with cheese, or an omelette with cheese and tomato, and usually bacon or some meat.  For lunch, a salad with whatever fat or protein I can put on it (cottage cheese, turkey, pork, hard-boiled eggs, etc.).  Dinner is almost invariably some sort of meat dish: chicken with vegetables, steak, burger without a bun.  Lots of vegetables with creamy dressings or dips.  Snacks are nuts (peanuts aren't the best choice, but they're really the only nuts I like) or cheese, maybe some lunch meat.  Dessert is whipped cream.  I mean, like, straight whipped cream, right out of the can.  I can kind of go overboard with it sometimes, but even half a can is less than 20g of carbs, and usually 3-4 mouthfuls will satisfy the sweet cravings.  I drink water and Diet Coke.  Once in a while I'll drink a low-sugar hot chocolate (that's like 4g of carbs).  I know Diet Coke is terrible for me but what else can I do?  I've tried to like coffee and tea so many times and I just can't do it.

How many/few carbs do you eat?
I'm not really sure.  A big part of my success with the diet is not being overly scientific or strict about it.  Many people I know track their carbs obsessively, but I know myself, and if I tried to be anal about it, there's no way I could ever stay with it.  (I downloaded an app to track my different "macros" but had to give up after a day.)  The recommendations I read from Phinney and Volek (which is a very good starting point in my opinion) is less than 50g/day for the first 2-3 weeks, then under 100g/day for "maintenance."  I can say with some confidence that I'm well below those guidelines, but I'm not zero.  If I had to guess, I'm probably usually in the 30-40g/day range.

Were you/are you able to train on that?  Do you use carbs in training or racing?
As I said before, it took me a good 3-4 weeks before I could really train the way I wanted to.  I was able to run mileage without a problem, but any kind of intensity--even just running slowly uphill--was a giant struggle.  This passed after about a month and then I was back to normal in terms of my training.  But it was a frustrating time.

I don't use carbs in training.  Many low-carb athletes do, including Zach Bitter, who uses specific carbs for specific, targeted workouts.  I don't do that for a couple of reasons.  For one, I'm a bit leery of jumping on and off the carbs.  In general, when I've taken a "cheat day" or had a couple of beers, I won't notice any ill effects, but I'd rather not make a habit out of it.  (Plus, if I'm going to have carbs, I want to really glutton it up.  You know, pizza, ice cream, the whole deal.  I'm not wasting carbs on a baked potato.)  Second, I don't like assigning a ton of value to any specific workout, to the point where I feel like I need the carbs to get the workout done.  If the workout doesn't come off like I want it to, so be it.  But mostly I just need to keep this simple.  Complicating it by adding carbs "strategically" is just another barrier to me sticking with it.

I do use carbs in racing, though, as many (if not most) low-carb athletes do.  My general race strategy is, a carbo-load the night before (to top off the glycogen stores); no carbs for breakfast--eggs and meat, as usual--and no carbs for the first hour of the race (usually just water).  After that, anything goes.  Gels still work fine for me, and I'll do some real food at aid stations--banana, PBJ, pretzels, broth, whatever.

I've heard that after you stop eating carbs and sugar, your body doesn't even want it anymore.  Is that true?
Ha.  Hahahahahaha.
No.

Does it really work?
Dunno.  It works for me.

*My apologies to Oscar Wilde.  I wanted a pithy title.