Nutrient Timing For Performance

by Kris Pitcher

Well what else would it be for?! Nutrient timing is an exciting topic because knowing what to eat is one thing...knowing when to eat is what will put you ahead in the game.

We can think about our day in a couple of important nutrient "time zones" - during exercise, right after, and the rest of the time. Simple. But first, let's talk about what's happening during those times.

When we're exercising we're expending energy. If we think about cardiovascular exercise we are typically using stored carbohydrate during this energy expenditure. Carbohydrate is stored as glycogen in our liver and muscles - so we're using that, or we're using blood glucose. The more intensely we exercise the more our body uses this fuel source. (This is why cardio is the least effective way to burn fat...but we'll save that for another day.)

Right after training we have a window of nutritional opportunity. We have the chance to replenish the glycogen stores, to shift from a catabolic (breaking down), to an anabolic (building up or synthesizing via metabolism) state, to grow and repair tissue, and to boost our immune system. Our hormonal environment is perfect for growth and repair and this is our chance to make nutrition work for us.

Our insulin sensitivity is improved because we're transporting and storing glucose in our cells. And it's been found that a combination of protein and carbohydrate replaces muscle glycogen faster than carbohydrate alone. This is the reason for the chocolate milk campaign.

The rest of the day is our growth opportunity. Our protein synthesis is elevated for more than 4 hours after our workout and our main goal is to achieve a positive nitrogen balance. We do that by providing enough protein to make gains.

Nitrogen balance referes to nitrogen from protein sources in the diet in relation to nitrogen excreted. If excretion exceeds ingestion, there is a negative balance (associated with infection and trauma). If ingestion exceeds excretion there is a positive balance (associated with pregnancy & muscle growth).

Are you still with me? Endurance trained athletes are going to need a lot more carbohydrates than a typical 45 minute/session exerciser. The take-away is to time your meals in accordance with your activity so you are adequately fueled pre-workout.

And by all means the gem here is the nutritional window of opportunity for post-workout nutrient timing. Getting 20 gms of protein and, for most men 20 gm of carbs, within 15-30 minutes post-workout is a must. Ladies, depending on your goals - your carbs may be closer to none. It's very individualized depending on your goals and your sport. But get your protein in!

Knowing when to eat is as important as knowing what to eat. Nutrient timing will truly take you to the next level in your progress. It will enhance your performance...it's the ultimate performance enhancing substance! Now, I'll see you later - I've got to get a meal in!