You got your first workout in and as one client put it so eloquently, “I was so hungry that I was ready to gnaw my arm off on the way home…” That about sums up the feeling you get after a high-intensity, energy-grabbing workout that is followed by the body seeking to replenish its spent energy.
Your post workout nutrition begins your very important recovery period. We all have heard about insulin. It is all the buzz in the diet world…don’t spike your sugar so you don’t spike your insulin… There is valid science behind this, but after an intense workout, it is the one time that spiking our insulin in a controlled healthy way may be advantageous. To understand the importance, I have to give you a quick physiology class on how the muscle tissue uses and replenishes energy.
When properly done, consuming the right post-workout nutrition can decrease muscle soreness, build muscle tissue, enhance immunity, and lower body fat. More specifically, consuming a Branch Chain Amino Acid (BCAA) enhanced Protein and Carb drink during or after exercise helps to:
- Decrease protein breakdown
- Increase protein synthesis
- Replenish glycogen
After an intense workout, muscle protein breakdown is elevated and the first thing you need to do is get the muscle tissue to begin protein synthesis (rebuilding). In order to maintain or build lean muscle mass the body must have a positive protein balance during recovery meaning it has plenty of protein for building and isn’t breaking down other muscle tissue for repair. It just so happens that the easiest way to shuttle protein into the muscle tissue is with glucose (sugar) which is required to spike the insulin and open channels for protein and glucose to enter.
Our muscles have stored energy called glycogen, which is nothing more than a chain of glucose molecules (sugars that come from carbohydrates). When a carbohydrate enters the digestive system, it ultimately gets converted to glucose where it enters the bloodstream. When it enters the bloodstream the pancreas reacts by sending out insulin.
The body stores this fuel mainly in the liver and in the muscle tissue in a form called glycogen that is the predominant fuel for high intensity energy expenditure. Any excess it does not need is stored as energy in adipose tissue (as fat). So one key to having more energy and less fat storage is to increase your glucose storage in the muscles. If the muscles can take up more glucose, then less ends up getting stored as fat. You force the muscles to increase their uptake by making them do more work. They then adapt and store more energy in order to meet the future demands that it is expecting you to put on them based on your historical patterns. So your muscles are a learning machine. Don’t use them and they will efficiently store less and allow the sugar to be converted to triglycerides and stored in adipose tissue commonly known as stored fat. Use your muscles more and they will take up more glucose out of the bloodstream and store it as glycogen, thus decreasing the need to store it as fat. The whole process is much more involved, but we will leave it at that for now.
When you workout, you spend the glycogen that is in the muscles by burning it for energy as well as using some amount of fat for fuel as well. This energy needs to be replenished before your next workout, and that starts right after your current workout.
In order to make this happen you need to be able to get the insulin receptors to open up channels into the muscle tissue to allow glucose and protein to freely flow in. This happens when you take in high amounts of glucose and cause the pancreas to release high amounts of insulin into the bloodstream. The insulin locks into receptors on the muscle tissue like docking stations, which open up channels for protein and glucose to enter into muscle tissue. Thus like a lock and key insulin docks into the membrane receptors and opens the door to allow nutrients in. These insulin receptors are always out on the surface of the membrane looking to lock into insulin molecules but they are more sensitive and in greater number right after you workout than at any other time.
Although your insulin is constantly working to open up channels in order to take up energy in the form of glucose and protein 24/7, it becomes resistant the more time that passes from the last time you expended any physical force. So right after your workout is when they are out in force and highly sensitive. Sit on the couch a lot and your insulin receptors become very resistant and don’t allow energy in the form of glucose to enter. Do this for enough years and consume large amounts of carbohydrates that you don’t need and Type 2 Diabetes may set in.
When the receptors are filled or “docked” with an insulin molecule, glucose or amino acids (protein molecules) are entering the muscle tissue but the receptor(s) is now busy or preoccupied and cannot open any more channels until they complete their cycle and emerge back out onto the muscle tissue membrane. This process is key to weight management and we will discuss this further in a future post. Just know that you have more receptors on your muscle tissue membrane in the first 30-60 minutes post workout and even for several hours afterward than at any other time of the day. As time passes the receptors become more resistant to docking with insulin. So this is the time to eat and not store fat/gain weight, but be reasonable—you could overfill the receptors here as well but you have a much less chance of doing so.
Now, what happens if you miss the window? Remember the old saying about opportunity knocking but you were not there? If you miss that first 30-60 minutes, you missed your chance until your next workout. That doesn’t mean you can’t continue to store energy but you will recover with less glycogen storage than what would have been possible. When you start your next workout, the muscle will not be as filled with energy as it could have been had you hit that first window of opportunity. You won’t be able to maximize endurance or strength gains to your fullest potential, and you could end up slowing your progress.
So what should you eat post workout? Your body needs fuel in the form of fast metabolizing carbohydrates and proteins to repair the damage done to the muscle fibers. So this is the best time for a protein drink with a select amount of carbohydrates included for refueling of the muscles. We will cover the amounts of what you should eat daily and how it interfaces with this meal/snack in another post, but suffice for now to say that most women may only need about 15 grams of protein and about 20-30 grams of carbohydrates for a high intensity 30 minute workout. Most men require about 20-40 grams of protein and about 40-80 grams of carbohydrates after a 30 minute high intensity workout depending on how much weight was used. This is dependent on the amount of lean muscle mass you have and the type of exercise you perform.
Weight loss candidates take note here. If you are a woman with over 20% body fat or a man with over 15% body fat and are trying to lose more weight than you should stick to just the protein drink without the carbohydrates or with reduced carbohydrates. The issue here is performance vs. weight loss. This will allow you to lose more weight but may impact your energy levels as your glycogen reserves may not be as full as possible for your next workout. Some experimentation is encouraged here. There is some unclear science out there on if your body can adequately convert fat to glucose for replenishment, but so far most studies show that fat conversion is not enough to get the muscle tissue filled back up to its maximum potential for the next workout. One thing is clear—if you have done at least 10 minutes of high intensity training, you should not be eating any fat as it blunts the neuroendocrine response. The high intensity exercise causes your hormones to rise with beneficial results including increased fat metabolism, but it is stopped quickly if you eat fats right after your workout. And you thought that food was not a drug? Think again.
Lastly save the post-workout drink for high intensity weight lifting, interval or endurance training lasting 20-30 minutes or longer. More casual aerobic movements like walking, gardening or a light bike ride should not require this level of protein synthesis and glycogen recovery as they more heavily rely on fat substrates for energy metabolism.
In the meantime make sure you get some nourishment right after your training to maximize recovery.