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Does Nutrient Timing Matter? A Critical Look
Advising clients to consume a balanced snack 2—3 hours prior to exercise and to consume a carbohydrate- and protein-containing snack or meal following the session helps them advance their workout, enhance their glycogen stores and recover successfully. Proper fuel stores carbohydrate and protein can enhance any workout, and the anabolic characteristics of the postexercise phase hold true for dedicated step, indoor cycling and boot camp enthusiasts alike. Depending on your goals, the correct timing for taking certain supplements may actually aid performance Stuart McGill, PhD states that a sustained contraction of the long thin muscles of the back can rapidly deplete these muscle cells of oxygen. However, contrary to popular practices, a diet extremely high in protein is not necessary. And if you consider that most carbohydrate ingested during and immediately after exercise will either be oxidized for fuel or sent to the muscle and liver for glycogen resynthesis and that even in the presence of increased insulin concentrations, the postexercise period is marked by a dramatic increase in fat metabolism 6; 7 , it should be clear that even a whopping carbohydrate and protein drink will not directly lead to fat gain. The timing is not important.

Post-workout “anabolic window of opportunity”

Book Review – Nutrient Timing

Therefore, how much we eat is critical in altering our body composition and indirectly, our performance. But conventional thermodynamic approaches tell just a portion of the story. After all, few people would benefit from focusing exclusively on weight gain or weight loss. Rather, the focus should be on the composition of the gain or loss.

If you're losing equal amounts of fat and muscle when in "negative energy balance" or gaining equal amounts of fat and muscle when in "positive energy balance," you're probably not taking advantage of the full spectrum of nutrition and exercise information available.

Although this might be a bit of an oversimplification of a complex topic, in some ways the thermodynamic approach of measuring calories in vs. If you have got the right genetics, the calorie in vs. But, if not, simply counting calories will probably just make you a bigger or smaller version of your former self and if you're unhappy with that shape, you won't necessarily like it at a bigger or smaller size. To address some of these limitations of the thermodynamic or "calorie balance" approaches, scientists recognized the value of studying the effects of food selection on body composition changes for more on this concept, see Lean Eatin' 1 and Lean Eatin' 2.

While this line of investigation is in its relative infancy, it's becoming clear that there is something to this whole food type thing. Despite what naysayers claim, once energy balance is accounted for, some carbohydrates are better than others. Likewise, some proteins are better than others and some fats better than others. Therefore, by choosing your food wisely, even if you're eating the same number of calories each day, you can up regulate your metabolism , shift your hormonal profile and alter the composition of your weight gain and weight loss not to mention reap the health benefits of a better diet composition.

As you can see, the science of what to eat has added to the how-much-to-eat picture and advanced our understanding of body composition manipulation. By recognizing the laws of thermodynamics and eating accordingly we can set the stage for weight loss or weight gain.

And by choosing our foods wisely, we wield the power to take control of what types of gains and losses we'll see. In some respects, the science of what to eat has given us the power to transcend some of our genetic "inclinations" i. While the how-much-to-eat and what-to-eat approaches offer plenty of great nutrition information, one newly-emerging area of research, "nutrient timing," has begun to demonstrate that manipulating the time dimension can further assist in taking control of our body composition and athletic performance.

In this way, nutrient timing, or the science of when to eat, is becoming an important part of nutritional planning. To the average person who is not exercising, the principles of nutrient timing are not very important.

For these individuals, what and how much they eat is the most important thing. While nutrient timing isn't critical to the average person, its importance must not be underestimated in the athlete including team sport athletes, endurance athletes, and weight trainers. In the book, " Nutrient Timing " a book I also contributed to , Drs. John Ivy and Robert Portman make a great comment about the current state of sports nutrition practice.

In other words, when many athletes find out that something is "good," they try to get lots of it. And when many athletes find out that something is "bad," they try to avoid it at all costs. Unfortunately this is nothing more than a combination of the how-much-to-eat and what-to-eat approaches discussed above. Combine that with a naive good vs. After all, few foods are always good or always bad well, I can think of a few?

This is certainly unfortunate for two reasons. First, much of the current science points to the fact that if you train regularly, the body is primed for fat gain or fat loss just as it's primed for muscle gain or muscle loss during specific times of the day.

Add in the wrong foods at the wrong times and you sabotage your efforts in the gym. Add the right foods and your efforts are given a giant boost. Secondly, although some foods are not optimal during certain times of the day i. Throwing aside the oversimplification inherent in the bulk nutrition concept, let's now get down to the nuts and bolts of optimal nutrient timing. Since I was a consultant in the development of the book, I'm going to go ahead and take the liberty of borrowing from some of Drs.

Ivy and Portman's nomenclature. In the book, the authors refer to three critical times of the day in which nutrient timing takes on a greater importance. Since I like these distinctions, I'll use them here. The Energy Phase is called this because this phase occurs during the workout when energy demands are highest.

As you probably know, the energy used by skeletal muscle is ATP. This ATP is formed and resynthesized by macronutrients from the diet so carbs, proteins, and fats contribute indirectly to the energy of muscle contraction. This breakdown of nutrients, while completely necessary, is, by definition, catabolic. As such, the workout period, as I've addressed in the past see Precision Nutrition - next week , is marked by a number of anabolic and catabolic effects.

Since this drink not only enhances blood flow but stocks that blood up with amino acids and glucose, the protein balance of the muscle will be shifted toward the positive and glycogen depletion will be significantly reduced.

In addition, those amino acids and glucose units, independent of their effects on muscle protein and glycogen status, can also lead to a decrease in cortisol concentrations and improve the overall immune response part of the acute phase response listed above and described in detail in the Precision Nutrition article.

Of course, if the aforementioned supplement is in a liquid form and is sipped during the exercise bout as recommended , dehydration, a potent performance killer in both strength and endurance athletes, can be staved off as well. When examining the science of nutrient timing in detail, it becomes clear that one of the key "when to eat" times of the day is during the Energy Phase or during the workout.

Of course, in focusing on when to eat, I'm in no way suggesting we should neglect considering what and how much to eat. In fact, they're probably your next two questions so let's get to them right away. As indicated above, during the Energy Phase it's important to ingest some protein and carbohydrate. In my experience the easiest way to do this is to drink an easily digested liquid carbohydrate and protein drink.

Dilution is important, especially if you are an endurance athlete or if you're training in a hot environment. If you don't dilute your drink appropriately, you may not replenish your body's water stores at an optimal rate 9; Now that we know when to eat and what to eat, let's figure out how much.

A sports nutrition regimen should restore muscle glycogen and rebuild muscle protein. To achieve this, nutrient "timing" is important in 2 ways:. Ivy and Portman do a great job of explaining complicated muscle physiology. Because of my scientific and healthcare background, I found the book easy to read. Nevertheless, some of it might be a little too scientific or advanced for the general reader:. Also, it doesn't help the reader optimize their nutrition regimen. This chapter could have been deleted.

Only the discussion of insulin is relevant, but, the authors should have spent less time summarizing the physiologic actions of insulin and more time explaining how changes in diet affect insulin output.

If you don't want to read the entire book, chapter 1 "Nutrient Timing" explains the principles and the table on p. I didn't like the fact that one of the authors has an affiliation with a company that produces 2 of the leading sports drinks on the market eg. Nevertheless, the content represents a fair, objective summary of published research. Quite simply, Nutrient Timing is one of the best sports nutrition books I have read. Despite my concerns about potential bias, I can still recommend this book highly.

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