by Jake Foster @jakerfoster
“If you don’t drink a protein shake within 30 minutes of training, you will lose all your gains.”
Every gym goer has heard this advice preached to them from trainers, muscle magazines, or other workout enthusiasts. That’s why most of us are quick to grab our whey protein shake, a smoothie at the gym bar, or hit up the local Chipotle as soon as we are done exercising. Because if we don't, according to the “bros”, we are not going to rebuild the muscles that we just worked so hard to breakdown.
So, we quickly scarf down our post workout meal to keep our gains safe. But, eventually, the workout high that we were feeling is quickly replaced by a gurgling in our stomachs. We feel bloated, uncomfortable, and have a sudden urge to either lie down or visit the nearest restroom. And no, that’s not the Chipotle talking. In fact, it probably has nothing to do with the food you ate. It’s “bro science” gone bad. You have been filling your body with calories it is not ready to digest.
Exercise inhibits digestion
We often forget that training is stress. Our bodies do not biologically differentiate between the stress felt in a car accident or the stress of a tough workout. Both stress responses trigger the body to divert energy away from its’ normal functions in order to provide energy to deal with the recent stressor. One of those normal bodily functions that require a massive amount of energy is digestion.
Digestion occurs within our gastrointestinal (GI) tract, which is a complex system of organs that use violent muscle contractions break down the food that we eat. These contractions take place within a “pool” of enzymes and stomach acid that help dissolve our food. But, in the midst of a stressful situation, digestion comes to a halt. Your body does not want to waste energy on muscle contractions in your gut when it needs that energy for your arms and legs. It stops producing enzymes, acid, and redirects blood flow from the stomach to your extremities. All of your body's focus is in facing the stressor at hand.
It is actually a beautiful design when you think about it. Our bodies innately know where to prioritize energy. This also makes it obvious why shoving food down your throat after you workout is a horrible idea. No wonder you feel bloated after your post workout meal. Your body has no energy to digest it.
What about the anabolic window?
Before ending this article, we need to clear up the myth of eating within a certain time frame after you train. We now know that this is a poor choice for digestion, but what about all the people who say it will hurt your gains? This idea is commonly known as the “anabolic window” and thanks to recent research, it has largely been disproven.
According to a study from the Journal of the International Society of Sports Nutrition, led by bodybuilding nutrition experts Alan Argon and Brad Schoenfield, there has been no clear evidence found that a large protein intake post workout will increase muscle gains. What is more important, according to the authors, is not the exact timing of protein intake, but the overall amount eaten in a given day. So, you don’t have to skip out on your tasty protein smoothie that you enjoy. Just don’t drink it right after you workout.
So, when can I eat?
You can eat when you chill out. Your body needs to transition from what is called sympathetic, aka “fight or flight” stress mode, to parasympathetic, aka “rest and digest” mode. This transition takes longer depending on the style of training you are doing. For example, an easy hour walk or bike ride requires less of a cool down period than an hour of high intensity CrossFit. As a general rule of thumb, for easier, aerobic exercise, wait at least 60 minutes before your next meal. For strength training or higher intensity exercise, wait anywhere between 90 to 120 minutes to eat. Unless you are a professional athlete who needs to train multiple times a day, you should not be concerned with quickly refueling your body with food. You should be more concerned with how you are going to let your body rest and actually digest your food.