Eating carbohydrates directly post-workout has always been an indispensable tactic for fitness athletes and bodybuilder. Bodybuilders and weight lifters eat carbs post-workout to replenish glycogen stores and to jumpstart the muscle rebuilding process. While it is undoubtedly true that eating carbohydrates replenishes depleted glycogen stores and it’s also true that we need food to rebuild muscles, scientific research suggests that replenishing glycogen stores is not the best method for building a lean muscular physique, in fact, it hurts it. We do need to begin the rebuilding process immediately post-workout, but eating fast-acting protein only is the best way to rebuild and get lean.
For all of my clients except extreme bulkers who are challenged to get in enough gross calories to grow, I recommend only a pure whey isolate shake immediately post-workout, followed by a full meal 60-90 minutes after the shake. This gives time for the protein to fully assimilate and begin the rebuilding process before we add any carbs or fats. Here are four reasons why doing it this way is far superior to eating carbs or protein + carbs post-workout:
Protein Synthesis (muscle repair) – More than one study had now demonstrated that including carbohydrates in post-workout nutrition does not improve protein synthesis. Studies have shown that eating just protein post workout dramatically increases protein synthesis, but adding carbs (in neither small nor large amounts) improved this process. In fact, adding carbs may actually hurt, which is outlined in #2 below.
Slows protein absorption – The addition of carbs (or fat, or anything you eat with it) to your post-workout whey Isolate shake slows the absorption of protein into the system and thus delays the muscle repair process. The reason for this is simple. Your body does not partition the foods and drinks we eat in the stomach and digest them individually. Rather, everything we eat at the same time is dumped into the same space for absorption, so by adding carbs or other foods we, in effect, dilute the protein and it takes longer to absorb it all. Look at this as a line to get on an amusement park ride. If only 30 grams of protein line up, then all 30 grams of protein get on quickly. However, if 30 grams of protein and 30 grams of carbs line up at the same time in no particular order, it will take a lot longer to get everyone on. This is also why many medications direct you to take them on an empty stomach, speed and totality of absorption.
Fat-burning – After we train (especially if we train really hard) our glycogen (energy) stores will be thoroughly depleted. When our body has no energy stores in the form of glycogen, it must turn to alternative sources to fuel itself, like protein and, most importantly, body fat! Since we just drank a big protein shake, our protein supplies are now abundant, so the body will be primed to pull from body fat for energy until we eat again. This works even better post-workout as this is a low-energy time, meaning that we aren’t expending a lot of calories. Being that your body can only pull from stored body fat so quickly, it will be able to pull everything it needs from body fat without much issue.
Growth hormone – Science has shown that GH levels are very high after an intense strength-training workout, which is great for the rebuilding process. When we eat carbohydrates, it triggers the body to spike another chemical, insulin in order to digest them (this is not true with eating protein and fats). Unfortunately, there is an inverse relationship between insulin and growth hormone, so as one goes up, the other goes down. So in effect, eating carbohydrates post-workout will drop your growth hormone levels and slow rebuilding even further.
For these reasons, I recommend eating only a quick acting protein post-workout for optimum growth and fat loss. This is best followed up by a full meal 60-90 minutes later, after the body has had a chance to both assimilate its post workout protein, keep GH levels elevated for a while and also burn through a bit of body fat. I have used this method personally with dozens of clients over the past few years and my own empirical evidence has yielded amazing results in body-composition for everyone who uses this method.