Does the Post Workout “Window of Opportunity” even Matter?
If you read my previous article on energy systems and sports nutrition (If you didn’t read it, click here!) you may be thinking that in order to have strength and especially muscular gains in the gym you have to be pretty anal about your Nutrient Timing. You may even have gone as far as to think that whether you lose or gain muscle mass or simply recover depends entirely on how quickly after your last rep you can get that perfect ratio of sugar (dextrose) & magical Progenix protein peptides from the shaker bottle to your lips. In my last article I said the very alarming statement “Crossfit is Aerobics” and now I am going to say something way more blasphemous….
Post Workout Nutrition Timing DOESN’T MATTER (almost)
Since the beginning of time, part of the bodybuilders 10 Commandments has been the Post Workout Window of Opportunity, which is like a time bomb ticking down. The only way to diffuse it is to have a perfect combination of protein and some kind of special simple fast digesting carbohydrate such as dextrose, maltodextrin and waxy maize, or a patented superduper combination of all three! If this Gain City Shake is not consumed, the bomb will go off, and will result not only in zero gains, but actually losing gains making the entire workout a waste.
If this is truly what you believe and have been told, then as my favorite sports nutritionist and natural bodybuilder Dr. Layne Norton says, “#yougotgurud” – Seriously type that into https://twitter.com/Search
Now it is generally wise to bookend your workouts with adequate protein and carbohydrates especially if you’re an athlete, however lets briefly look at the 3 primary reasons for the Dogma of Post Workout Nutrition:
1. Glycogen Replenishment
2. Preventing Protein Breakdown
3. Raising Protein Synthesis
Glycogen Replenishment
This is perhaps the primary reason for the term “Window of Opportunity” as there is a legitimate window after exercise where our muscles are more permeable to glucose uptake, primarily because of the translocation of a protein called GLUT4 from the muscle belly to the membrane of the muscle. Both insulin and exercise signals GLUT4 to move to the surface of the muscle whereupon it acts like an open door or gate allowing glucose to freely travel into the muscle where you need it most. It is even shown that after this 2 hour Window the rate of glucose uptake can decrease by as much as 50%, which is huge.
With all the evidence in support of the all-important PWO timing, you can understand why we have placed so much value on glycogen replenishment. However, the need for immediate glucose intake post workout is based on a few presuppositions:
1. Our glycogen is completely empty after a workout: This is typically only true if you either didn’t begin your workout with a full tank of glucose, or your workout last over an hour of continuous work. A typical CrossFit workout might begin with a low volume Strength or Olympic lifting Part A of roughly 3-6 sets of 5-10 reps at 65-85% maximal intensity, and finish with an 8-20min. MetCon. This workout would use up roughly 30-60% of our muscle glycogen.
2. I need my glycogen to be completely full immediately: Roughly 95% of the members at Beaverton CrossFit do only one workout per day, 4-6 days per week. So why? Why are we in such as rush to have full gas (glycogen) tanks if we aren’t working out for another 24hours? The point is there is no rush for almost all of you! You can relax, as even though glucose uptake is fast immediately pwo, it almost doesn’t matter as you have plenty of time to recover.
Preventing Protein Breakdown
Insulin is anti-catabolic, which means it can prevent protein breakdown post exercise, which will then contribute the muscle hypertrophy. This has led to a lot of post workout insulin spiking via simple carbohydrates. There are two problems, one with the research and the other with application. First much of the research has been done in a fasted state, which greatly increases protein breakdown. Second, the effect of insulin on net muscle protein balance has a plateau that can easily be reached with amino acids or protein alone, without the added carbohydrate.
Raising Protein Synthesis
Muscle Protein Synthesis (MPS) is required for the growth and repair of skeletal muscle mass (hypertrophy). Following a workout MPS is already elevated from the workout alone and the studies are extremely mixed as to whether immediately consuming protein has any added beneficial effect on MPS. The conclusive studies are again done in the fasted state. So the beneficial effect of increased levels of MPS post workout will likely have more to do with the previous meal consumed 1-2 hrs. pre-workout or an amino acid or protein supplement consumed 10-30min. pre workout.
Conclusion:
For 95% or more of you, Post Workout specific nutrition and timing is nothing to freak out about. This is assuming you are eating 3-5 mixed healthy meals per day and getting roughly 30-45g of protein per meal. It is still generally good practice to consume a hefty meal post workout, which can be in the form of a protein shake, however its not necessary. If anything all I want to make clear is that after your workout there is no incredible rush to chug down a carb/protein shake, but rather you can take your time, go home and make a meal.
Exceptions: For the 1-5% of you, who fit the following description, being a little more attentive to PWO timing and quality will likely give you an extra edge.
• You are very lean: 3-8% BF
• You workout 2 or more times a day, totaling over 60-120min of work
• You are an endurance athlete
• You workout fasted
Did you find some or all of this information helpful? Do you want to sit down with Marcus one-on-one and get your nutrition dialed in? Email Melissa and get a consult set up! mgriffin@beavertoncrossfit.com