Its About Time -Part II, Nutrition Timing

Written by drtweedt

Does Nutrition Timing Matter?

We have all heard about the importance of proper nutrition in meeting our fitness goals. But, does timing matter? In other words, does meeting our nutrition “macros” mean that we will achieve optimal results? Obviously, by the context of the question, nutrition timing matters.

The ratio matters if you want to maximize your body’s ability to build muscle and burn fat. As pointed out in the book, “Nutrient Timing” by John Ivy, PhD, the use of carbohydrates following exercise allows the body to stimulate insulin and blunt cortisol. This helps drive protein synthesis and decrease muscle degradation. So, several studies looked at this effect to determine the amount and timing of the carbohydrate replenishment. They found carbohydrates exceeding 0.5 grams per pound of body weight per hour lead to a plateaued result.

Does that mean we just need to drink our Gatorade after we workout and that’s it?  No.  Obviously we need to look at the effect of protein as well.  Researchers discovered that the addition of protein, to the carbohydrates, helped maximize the body’s ability to restore muscle glycogen. Why is that important? Researchers from the North Texas State University School of Medicine and the University of Texas looked at the two groups. The first group consumed the carbohydrate / protein drink and the second consumed a simple carbohydrate drink within 45 minutes of exercise completion. Then they had them exercise to exhaustion. The first group was able to outperform the second by 55%. But since we don’t all exercise to exhaustion, we need to know if this translates into other benefits.  Therefore, groups from Vanderbelt, The University of Texas, and University of Maastrich in The Netherlands found that this same ratio advantage translates into a protein synthesis advantage. Comparing the carbohydrate / protein group to a protein group alone, they still outperformed them in protein synthesis by 38%. So, if you are simply drinking your Gatorade or simply drinking your protein drink, after you workout, you are missing out!

So, how can we take this information and translate it into an applicable advantage? Lets break down the post activity period into two phases by the body’s ability to respond to insulin and thus repair. The first phase is the Anabolic Phase. This is the short, post activity, period following exercise when the body is primed to rebuild since the natural insulin : cortisol levels are favorable. However, if this is not stimulated, the window closes quickly as the ratio reverses. The second phase is the Growth Phase. This is the time when the body can take full advantage of the primed anabolic phase. Now the body rebuilds muscle and burns fat. Looking in more detail:

Nutrition timing

How appropriate nutrition timing can modulate post-exercise insulin levels

Anabolic Phase

Since your body is primed for the anabolic effects of insulin during the initial post exercise phase, we need to take advantage and optimize this window. Therefore, we have to maintain a high carbohydrate to protein ratio. In looking at the studies, Dr Ivy states that the optimal ratio is about 4 grams of carbohydrates for each 1 gram of protein. The carbohydrates should be high glycemic such as glucose, sucrose and maltodextrin. Finally, but most importantly, this should be consumed within 45 minutes of exercise completion, otherwise, you lose the optimal window as your natural insulin levels decrease and cortisol levels increase.

Growth Phase

Rapid Phase

If you have taken advantage of this initial anabolic phase by consuming the proper carbohydrate to protein ratio, your body is now primed to build muscle and burn fat. However, like any car, simply turning on the ignition is not enough. During this second phase, your body needs fuel to take advantage and maintain the anabolic machine. Since, maintaining a high carbohydrate load and stimulating insulin could lead to fat deposition, we now change our ratio to a higher protein and lower carbohydrate ratio. One gram of carbohydrate to 5-8 grams of protein is ideal.

Sustained Phase

This is the long period of recovery lasting from about 4 hours after exercise to the next day. So, we continue the 1:6 carbohydrate to protein ratio as discussed before. The only difference is that you start to shift away from pure whey protein, which has rapid absorption to a casein based protein before bed. The longer absorption of Casein, allows your body to stay fueled during your overnight fast.


Take Home Points:

While most of this seems geared to the weightlifting population, it is actually applicable to everyone who wants to get fit. Priming your body doesn’t simply mean that you will gain nondiscriminatory weight. If you adopt this fitness model, your will find that your body will react and your fitness goals can be achieved more quickly. Exercise and nutrition go hand in hand. In other words, you will not succeed to your optimal level if you don’t pay attention to both.

In a practical sense, I use shakes to meet this nutrition goal. It is extremely difficult to plan your daily meal plans, fuel your body, achieve your caloric intake and still maintain your day job. So, when I looked back at the options, I found that BeachBody’s Results and Recovery meets the Anabolic Phase goals with the ideal ratio. The Growth Phase can also be met easily met but requires a bit more attention to the protein to carbohydrate ratios.

After applying this to my current program, I can see a marked improvement.  Although, its been repeatedly stated, its worth repeating: Food Is Fuel.  It’s up to you to decide how well your body runs.

Nutrition Timing Summary

Nutrition Timing Summary


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