Tuesday, March 21, 2006

Fuel

I had a post a few days ago that provoked some comments and discussions regarding fueling before and during the run, specifically the long run. Kristine (Kconnor) from Austrailia posted this article in the comments to complement the other two articles on the subject I mentioned.

Here's my pre-run-ritual, which I described this way back in September-
1. Wake at 4:30am, stare up at the dark ceiling in bed for a few minutes.
2. Start the coffee, dunk the whole-wheat english muffin in the toaster, pour some o.j..
3. Eat the muffin with peanut butter and jam, drink the juice, coffee and a glass of water at my daughter's miniature ladybug table in the kitchen with the lights off so I don't wake the kids up.
4. Lace them up and head out the door (stuff a few salted pretzels down my gullet if it's 16 miles or over).

It was lighter in September, so I sleep longer now, and I also skip the pretzels since it isn't as hot and I don't need the salt. I've never gone into a run after fasting, and since I almost always run in the mornng I can't do the oft-repeated "eat 2-3 hours before running" fueling refrain. I figure my meal is 550-600 calories or so, and while the juice and jam probably give me a bit of an insulin spike, it's a routine that works for me.

Where I'm trying to change things is in the way my body utilizes fuel in the later stages of my long runs. We all read about how the body uses primarily carbohydrates, stored as glycogen as fuel for working muscles. We also know that we can only store so much of the stuff, and when we deplete this fuel source the body starts to burn fat in tandem with glycogen. Finally, when there's no more glycogen (and exercise continues), the body finally starts to break down muscle as it continues to burn fat. We slow down dramatically at this point.

I seem to have some trouble when the body transitions from using primarily glycogen to depending more on fat. I'm hoping to find a way to make this transition more gradual-to start burning fat sooner while conserving glycogen. One way I'm trying to do this is by not confusing the body by feeding it more calories (usually in gel form) when I start (or sometimes before I start) to feel a little tired. If the body knows it will get a quick shot of 150-200 calories everytime it starts to feel the burn, there's no reason for it to learn to conserve what little glycogen is left after 90-120 minutes of running. By doing more 22 milers without gel, hopefully I can get the body to adapt and start saving more glycogen by burning more fat earlier in the run. Hopefully, this will help me when I actually do use a gel or two during the marathon (or during longer marathon pace runs).

One of the potential problems I see in this approach is finding myself too depleted too often. As in the article Kristine posted, this can seriously suppress the body's immune system, leaving it open to sickness (hmmm, I know about that) and injuries. To combat this, I need to remember to stock up on carbohydrates and some protein right after these runs, when I'm most vulnerable. Again, this isn't for everyone, and it isn't strictly Lydiard although Nobby did suggest it. My guess is that Arthur would say to do whatever you need to do to get the workouts in, and for some that would mean a gel for every run over 10 miles. As always, the most important thing is to keep running, even if if means strapping a box of jolly-ranchers to your back.

Training: 12 miles with Lucas, 1:27:22, 7:17 pace

11 comments:

Johnny Lyons said...

That sounds like a useful tactic, if you survive it like you were wondering. Maybe you can just do those depleted runs at very specific points in your training where you're slightly more stable and not gaining as much. You might have already been planning it this way. I guess I mean to do it on a week where you're not trying to increase mileage or speed work, or hills, etc. Or maybe do it before an easy week. Do you know if you need to do depleted runs often to be effective or just occasionally?

Mike said...

Hey Johnny, thanks for the comments about Pemberton, I'll give it some thought. My thoughts right now are to do probably two "easy" long runs without any fuel followed by one "workout" long run with some amount of marathon pace or tempo with a gel or two. I'm not sure how I'll handle my second 28 miler. I'll probably need one gel to avoid being scraped off the road. I'll listen to the body, and if I don't start feeling better at the end of these after a month or so I'll reconsider. Nothing ventured, nothing gained I guess, but I don't want to start dreading long runs as punishment.

Scooter said...

Mike, thanks for a clear presentation of a concept that affects many of us.

Dallen said...

I agree that the body would benefit fron no gel on long runs. At tha same time it also needs to learn to process fuel after 22 miles. Without any scientific basis I like to alternate between the two approaches.

brian said...

My long runs aren't 28 miles, but I've been trying the same thing--not taking anything during the run in the hopes that it will teach my body to be more efficient. I do plan to use gels during my longer long runs and when I put in some marathon/tempo pace during them. My morning routine is to make a glass of Carnation Instant Breakfast and drink half before I run and then the other half when I get back.

Evan said...

I'm with Dallen on this one. One of the best ways to train the body to spare carbs is to roll out of bed in the morning, drink only water or coffee, and go running. No food. If you're going to do anything quicker than marathon pace, take a gel once you've started running.

The overnight fast followed by any length run is a great way of teaching your body how to run on fat. You have to refuel immediately (within 5-10 minutes of finishing) after the run if you don't want this to lead to slow attrition of your muscle glycogen and delayed recovery from runs.

The overdistance (26+ mile) runs are a different story. You can screw your week nicely if you persist on those without fuel. Don't feel ashamed to take a gel at mile 24 of a 30 miler ...

If you have to slow your pace for a week or two or three while your body adjusts to doing morning runs without food that's probably OK in the long run. I think the body actually adapts pretty quickly to changes in nutrition like this.

(Rather than cluttering up your comments, email me if you want to discuss this some more. I've been doing the morning runs without food since the 20th century!)

Evan said...

P.S. Not sure what you mean by strictly Lydiard ... but I don't think Snell, Halberg and Baillie had gels when they were out doing the famous Waiatarua 22 miler.

My sense from doing long runs with New Zealand harrier clubs for years is that the received version of Lydiard training was to do at least one of the long weekend runs (the 20+ miler often on Sunday, after a Saturday race) straight out of bed before breakfast. So I'd say it's hewing closer to Lydiard to forego the gels. My 2c worth.

Mike said...

Here's the McMillan article I'm referencing, which really goes with what Evan says here. Evan, are you sure they didn't pass a big jar of honey around? Kidding, but I'm sure you get the reference. Not eating breakfast is the next logical step I suppose, but it will be a real change for me. I guess I used to think I couldn't run 100 miles in a week either. The body does have an amazing ability to adapt. No coffee pre-run would probably be the hardest for me. I just couldn't drink it on an empty stomache.

Evan said...

Not sure what the latest scientific word on this is, but I think they still say that caffeine has a positive effect in aiding the metabolism of fats, or decreasing perceived exertion at a given pace. So if you can do the coffee by itself before the run that can be helpful.

Oh, those harrier honey parties, they were something :)

Sasha Pachev said...

Mike - you probably have plently of fuel capacity to run a 2:10 marathon. Just not the engine/transmission combo. So you rev it up, and it burns fuel for the first 2:10 of the race as if you were doing 5:00 miles. But you are not doing 5:00 miles, so 2:10 after the start you still have 4 miles to go, and no more fast fuel.

Don't worry about capacity - work on the engine/transmission to crank up the RPMs, not lose momentum, and thus not burn so much fuel.

I once overheard a conversation between a 50+ year old ultra runner that took 2:55 to run a marathon, and a 2:16 marathoner. The slower one asked the faster what he did to build his fuel stores. The faster one was rather puzzled - he did not have to worry about it.

Thomas said...

I did think about that very problem a while ago - gels or no gels for the run. On the one hand, you're supposed to drain your body of glycogen during the long run. On the other hand, you are supposed to do the same thing on your long run as you do during a race. As I'm not planning on doing a marathon without gels, I'm still taking one or two on my long runs (well, anything over 15 miles).