"There's only one hard and fast rule in running: sometimes you have to run one hard and fast."

Tuesday, March 12, 2013

1) Fueling strategies

In 5 years of blogging, I've intentionally steered clear of writing about how to fuel when running. The reason: diet is the refuge of the lazy athlete. Everyone would like to believe they can improve, not by training more, or harder, or smarter, but by swallowing something. "You like to eat; you hate to work - I get it - now let me get back to business." My belief has always been that the body will adjust to almost any type of fueling and it's simply a matter of preference, that no one diet is inherently better than another; it's time to see if I can justify that.

There are three pure strategies of fueling. The first is the Constant Supply model, the current standard, where one ingests carbohydrate continuously during exercise. Among ultramarathoners, the prime example is Yiannis Kouros; during the Sydney to Melbourne 960K (600 Mile) race, he ingested 7800-13770kcal per day and expended a calculated 7736-15367kcal, with a 5 day total of 55970 ingested, 55079 expended. [Rontoyannis, 1989, quoted in Noakes' "Lore of Running"] His fuel was 96% carbohydrate. It is interesting to note that Noakes has published that one can utilize only one gram (4kcal) of carbohydrate per minute, when ingesting at least 70-100g per hour [citing Hawley, 1982; Wagenmakers 1993; Saris, 1993].

The second pure strategy is the Constant Deficit model, following a ketogenic low-carbohydrate diet. Perhaps the best ultrarunner currently touting this is Zach Bitter.

The third pure strategy is the cyclic Feast and Famine model, which I fell into through habit and inclination. This method alternates periods of high carbohydrate load with periods of low carbohydrate supply.

There are also mixed strategies, which complicate matters. For example, many marathoners will use the Feast and Famine model only in the week leading up to a major race.

What I hope to cover in the next posts is how the body utilizes fuel during exercise, how one can alter that through diet and/or exercise and what that means for anyone trying to optimize race performance.

I expect the answer will not satisfy anyone.


Running with MTP said...

I like the take enough fuel to make your run a success. You know you body well and I am confident you know if you will run a risk of coming up short on your current workout.

If I am full of glycogen, I do not need anything for a 20 miler. If I am not full, I do. How much I need is dependent on my current supply ~ If I am near empty then I need a contant fueling strategy.

In any runs > 3 hours, I will need something. In my 4-4.5 hour routine trail run, I tend to tke 100 calories per hour the 1st 2-2.5 hours and then 300 per hour the last part.

In runs 5+ hours, I usually follow the constant supply ~ 300-400 calories per hour from the start.

Unless I am completely empty I would not fuel a run under 10 miles.

So I think the answer is situational, but I have no need to run out of fuel in a run (although it happens sometimes)

But if you made me pick between one of your choices it would be constant fueling.

Karen said...

I'm more of a constant fuel person too. I don't fuel on runs less than 2 hrs. Anything longer, I'm usually out running instead of having a meal so I like to take 100 cal an hour and that seems to go well.

wildknits said...

I definitely fall towards the Constant Fuel end of the spectrum.

I attribute some of my 'success' at Sawtooth this past year to my husband handing me turkey jerky at Co. Rd 6. From then on I took a chunk along and really felt that the added bit of protein (and salt) made a big difference in how I felt. So much so, I was searching for him, and the last tiny piece of jerky at Oberg.

That said - there was also the heavenly peach at Crosby-Manitou....

Looking forward to seeing how this all plays out...

Carilyn said...

I don't seem to have ANY sort of consistent fueling method - I'm the Sybil of fueling. The only consistent thing I've noticed over the years is that I do seem to run better with more protein before and during the run. But I think this has more to do with my weird blood sugar issues than any sort of "valid" strategy.

Robyn said...

A barrier to the Constant Deficit method is the level of commitment it requires -- as I understand it, you need to be ketogenic All The Time, not just during the run (or in the 24 hours before the run). This requires a radical (for most) and long term diet change. By contrast, you should be able to do Constant Fuel on virtually any diet (though undoubtedly better on some than others).

On a nearly-unrelated note, I have wondered how much of the well-being people report on a ketogenic diet has to do with eliminating gluten and other so-called proinflammatory foods, and how much has to do with the high-protein, high-fat, low-carb macronutrient breakdown. (Not sure how much I buy into the "inflammatory food" idea, but after eliminating gluten in our household, the improved health and behavior of 75% of the residents is striking. I seem to be the one who is not particularly affected by gluten, one way or the other).

Jean said...

I am really interested in reading this series of posts, Steve. I've never been kind of scattered about how I fuel before and during runs, so I look forward this.