Tuesday, March 31, 2009 by Daniel

CrossKitchen: Post Workout Nutrition

crossposted at Crossfit EastBay

So now we know that a double espresso before a workout works wonders, but what about afterward? The topic of post-workout (PWO) nutrition is a hotly-debated one over in the bodybuilding territories of the internet. Over there, the debate is typically not whether one should have anything post-workout, but rather which super-mega-extreme frothy tanker of aspartame and diheximethylcrapalose* (now in Fruit Punch flavor with real Acai!) will get you totally shredded (or pumped, I guess, depending on your goals). Bypassing the hype, though, is there anything that sets the post-workout window apart from any other time for nutritional benefit? Turns out, there is.

The Why
I'm going to geek out on you here for a second. As you may or may not know, the body provides three separate pathways for generating and burning energy: ATP/CP, Glycolitic and Oxidative. In the first, the body burns adenosine tri-phosphate for extremely brief (under a second), maximum-effort movements. In the second, the muscles burn through their reserves of glycogen at about 90% effort, which lasts about 12-15 minutes. The final is the domain of the endurance athlete, in which the body combines oxygen from your lungs with bodyfat reserves to allow you to work at about 50-70% for, essentially, hours on end. CrossFit metcons specifically target the second pathway, focusing on intensity rather than strength or volume. We will focus on strength (Max Effort) sometimes, and will occasionally dip into volume (Murph or a 10k), but the heart of CrossFit is the short, painful metcon (Fran is a classic example). It is here that PWO nutrition is the most useful.

You see, immediately following a punishing workout, the muscles are desperate to replenish their spent glycogen stores. The body can supply their needs by mobilizing body fat or by converting protein to glycogen, but these processes take time! And your muscles are thirsty! They need their glycogen NOW, dammit! Here's where the magical non insulin mediated glucose transport comes in. In the period of time immediately following a workout, we can fly in an emergency shipment of nutrients and amino acids directly to the muscles in a sugar airlift. It's the most direct line from mouth to muscle you'll ever get, so it's a good idea to take advantage of it.

Why? RECOVERY. As you all know, 5-6 workouts a week is brutal, and there's nothing like a bad case of DOMS to wreck your day. And it's not just about soreness: faster recovery means you're able to hit the workouts harder more often, thereby providing greater stimulus and growth to your muscles and central nervous system. Faster recovery means fewer injuries, and less likelihood of illness or overtraining. Remember: we do not get stronger in the gym. All we do in the gym is controlled damage to ourselves. We get stronger as a result of our body's response to that damage, so it is in our best interests to maximize our recovery by as many (legal/safe) means as are available to us.

The What

Hopefully by now I've convinced you that PWO nutrition is a good idea. "But what," you're asking, "should I EAT? Which is better, Gatorade or Muscle Milk?" The answer, of course, is neither. Sure, you could lay out $50 for a tub of chalky-tasting chemicals specially formulated by marketing agents with a penchant for the letter "X," but why bother? There are cheaper, healthier and tastier options.

When considering your choices, these are the things you want to keep in mind: a generous amount of carbs, a small amount of protein, and as little fat as you manage. Now, normally I'm not a very big fan of the carbohydrate, but in PWO-land all the rules go topsy turvy, so now they're good - and the higher their GI, the better (I know, right?). As for protein, the ideal ratio of carbs to protein is 4:1, so about a quarter of the carbs. Fat slows digestion/absorption, so while most of the time I'm huge fan o' the fat, this is not its time to shine. So what fits the bill?

  • Chocolate milk. As crazy as it sounds, lowfat chocolate milk is just about perfect for post-workout recovery. It has that great 4:1 ratio and is quickly absorbed by the body. In clinical studies, it performed as well or better than the highly processed fancy supplements. If I were to get really nitpicky, I'd advocate one made with sugar rather than high-fructose corn syrup, but whatever.
  • Regular milk. Rebecca's drink of choice. Organic is better than not. Lowfat versions have less fat, but whole has more nutrients, so I put that choice down to personal preference.
  • Kefir. This is what I drink. I have my reasons.
  • A sweet potato and a little jerky or salmon
  • An apple or banana with some skim mozzarella or deli slice
  • Applesauce with a little cottage cheese and cinnamon
  • Lowfat yogurt or rice pudding
  • Mix a little unflavored/unsweetened whey with some juice
You get the idea. Eggs, tofu/legumes, brown rice etc are suboptimal, as the fiber and/or fat makes them slow to digest and absorb. For 30-40 minutes of your day, fat and fiber are bad and sugar is good.

The When
Note that this little trick only works if you've pushed yourself hard enough to deplete your body's glycogen stores. So your special PWO meal/drink will only be effective if taken immediately after a hard metcon - the harder you worked, the better it will work, and the more immediate the better. The window is only open for about an hour - after that, your body has returned to business as usual. This is not to say that nutrition after a Max Effort workout would be bad for you, just that it wouldn't be any different from any other time of the day.

The How
This is not rocket science. Obtain a portable drink container and/or some tupperware and make it happen, Einstein. Try it for two weeks and see how you feel.

Personal Observations
For the last month or so, Rebecca and I have been following up our workouts with 16 oz of milk or kefir. We have both noticed a decrease (not an elimination - this ain't voodoo) in DOMS, and a greater level of energy in our workouts through the week. It's great stuff. If you have questions or your own PWO nutrition strategy, please share in the comments.

Note that if your goal is weight loss, you might consider intentionally NOT eating in the hour after a workout. In the absence of glycogen and and food, the body's response to a difficult workout will be to mobilize fat stores to replenish its immediate energy reserves. The downside of this, of course, is that you're missing out on the benefits of increased recovery, so you need to be very careful about walking the line between healthy and overtrained - if you push too hard, you'll spike your cortisol and your fat won't be going anywhere.

*As far as I'm aware, there's really no such thing. Not that any of us would know.

I am not a dietician. CrossKitchen articles come from my personal experience, observations and research, and should not be construed as professional medical advice.


Jenn said...

Good stuff, Daniel - makes a lot of sense. Number One Son swears by a big glass of chocolate milk after a soccer game.

I'm trying to be better about eating within an hour of a tough WOD. My problem is that if I have hit a WOD really hard, my stomach doesn't want food anywhere near it for an hour or more. After I did One Gross WOD with Jason last weekend, just the smell of KAD's lunch was enough chase me away from the table.

Maximus Lewin said...

Jenn - that is in your head. Finish WOD. Catch breath. Suck down 1/2 quart chocolate milk. Delicious and once you see how much better you feel you will want to do it.

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