[ Q ] You've written a lot about post-workout nutrition. How important is it to take advantage of insulin post workout?
It depends on your
goals. For starters, just so that everyone is up to speed, insulin plays important roles in both carbohydrate and amino acid uptake across the muscle cell membranes as well as acts as a key signaling molecule to stimulate protein synthesis.
The insulin signaling pathway is an elegant one because once the insulin molecule binds to the cell membrane, it sets in motion two different chemical messenger systems that accomplish three goals:
- This system increases transcription (RNA formation)
- Increases glucose uptake into the cell
- Increases the translation of the cellular RNA into protein. Although there are other pathways that stimulate translation of RNA into protein, the insulin pathway is one of the most important nutritional ones.
I hope it's clear, therefore, that insulin plays a critical role in post-workout recovery of protein balance. Now, whether or not we need a HUGE insulin burst depends on our goals. If someone is interested in maximum growth and recovery, lots of carbohydrate, protein and insulin should flood the body immediately after a workout.
img src=../store/end/acc.gif align=right border=0> With respect to glycogen synthesis, once you get enough glycogen resynthesis to pass the insulin independent threshold (see below), you'll need that extra insulin to boost cellular uptake of nutrients. My research shows that when full glycogen depletion is induced, carbohydrate only drinks and carbohydrate plus protein drinks perform similarly with respect to glycogen resynthesis.
However, when full glycogen depletion is not induced, drinks containing protein and carbohydrates offer much more glycogen resynthesis. I think this happens because anything will help restore glycogen when glycogen is very low (due to upregulation of glycogen synthetic enzymes and even the branching structure of the glycogen itself) but when glycogen isn't fully depleted, it takes a strong signal to drive synthesis and the insulin signal (from protein and carb drinks) is strong enough to do it.
Of course, these drinks also give a better insulin response than either protein or carbs alone. Furthermore the protein is critical for flooding the muscles with amino acids for enhancing the translation of RNA into new proteins.
On the other hand, if someone is interested in getting as ripped as possible, topped off glycogen isn't a goal. Since a huge insulin response might be counterproductive to fat loss and therefore a simple amino acid flooding may be all that's needed.
But before I move on I have to say that I often go back and forth on this one in my mind (that's why I say "might" above) especially in the case of very low carb diets because a big post-exercise boost in insulin (as a result of a carb plus protein drink) may rapidly promote recovery and muscle preservation as well as rapidly bring blood glucose down and bring you right back into ketosis.
Furthermore, studies show that the body shifts toward fat oxidation during the post exercise period even in the presence of high insulin. This means that even in the presence of hyperinsulinemia, lots of fat is still burned, leaving all the carbs to be stored preferentially.
So I'm not totally sure which is a better strategy for dieters. Usually I just try the carbohydrate and protein drinks in all trainees during the post exercise period and if there is a noticeable stagnation in the rate of fat loss (at very low body fat percentages), I have them drop the carbs and use protein only to minimize the insulin response while still providing amino acids.
[ Q ] If one were insulin resistant, would consuming a larger amount of whey protein minus carbohydrates suffice for post workout?
Again, it depends on their
[ Q ] Soooo...
Hold your horses.
In this situation it also depends on what we mean by insulin resistant. If we're talking clinically measured insulin resistance, the individual is probably in need of serious weight loss (because obesity and heart disease are characteristic of true insulin resistant) anyway so in their case, the latter suggestion of just amino acids is probably warranted.
Interestingly, type 2 diabetics (people with real insulin resistance) see an equal insulin response whether they ingest protein or carbohydrate - so perhaps a smaller protein only drink is warranted.
While I'm no expert on diabetes, it is important to note that insulin resistance is characterized by a larger insulin release in response to a normal carbohydrate or protein load. In other words, because muscle and fat cells are partially resistant to the effects of insulin, a whole lot of insulin needs to be released for it to do its job.
Fortunately for diabetics, exercise can dramatically increase the sensitivity of the muscles for glucose uptake and overall insulin sensitivity. Therefore the postworkout period is one time where diabetics are more normal.
With your question, though, I suspect that you are more interested in those weightlifters or athletes who think that a slight propensity to gain more fat on a higher carb diet means that they are insulin resistant. In this case, it's become clear to me that a lot of athletes have just enough knowledge to be dangerous.
Somehow they think that they can diagnose their own insulin and glucose tolerance by how they "feel" after a carb meal. That's nonsense. Therefore if someone suspects some sort of carbohydrate or insulin problem, they need to get their doc to check them out by doing a 3-hour oral glucose tolerance test complete with insulin measures as well as blood glucose measures. That's the only way to be sure if there is a legitimate problem or if they are just eating poorly and that's why they're too fat.
However, with that said, it's important to note that insulin resistance is a sliding scale. You don't need to have full-blown diabetes to be on the road to it. If your blood work shows some impairment in glucose and insulin tolerance, you need to start managing your overall nutritional plan with a higher protein, lower carbohydrate (low GI carb) diet. In addition, supplements like fish oil and rALA can help out too.
In this situation, with respect to post-workout nutrition, the great thing is that the person with borderline insulin resistance can do the same thing as someone with normal insulin tolerance. Here's why. First of all, if someone is insulin resistant, they need more insulin to do the same job (in terms of lowering blood glucose).
Therefore the synergistic insulin release associated with protein and carbohydrate consumption should drive insulin high enough to do its job with respect to stimulating protein synthesis and increasing glycogen storage. Interestingly, since recent data has demonstrated that there are insulin dependent and independent stages of glycogen recovery during the post workout period, it's important that insulin resistant people get their carbohydrates during the early stages of recovery when glycogen recovery is insulin independent.
You see, in any given muscle fiber, if glycogen concentrations are low enough (below 35mmol/L for anyone who cares), even in the presence of low insulin concentrations, glycogen resynthesis is maximal when enough carbohydrate is around. Therefore after exercise, especially high intensity strength exercise (where type II fibers may be very depleted) or high intensity aerobic exercise (where type I fibers may be very depleted) the provision of carbohydrate can assist with glycogen recovery during the insulin independent phase of glycogen resynthesis.
During this phase of glycogen resynthesis, even type 2 diabetics have normal glycogen recovery. However, once above the glycogen threshold, during the insulin dependant phase, the synergistic insulin response associated with protein and carbs can help pack those fibers full of glycogen again.
So although it's customary to prescribe low carb (especially low GI) diets for those with some degree of insulin resistance, the post exercise period is the one time of the day when insulin tolerance is much better than the rest of the day. So use this time to promote growth and recovery. You can use the rest of the day to avoid carbs and take supplements to improve glucose and insulin tolerance.
[ Q ] Alright, last question, I swear. How effective is ALA or R-LA in terms of being an effective nutrient partitioner during the post-workout period.
Recent data is demonstrating that the r- isomer of ALA is a very effective nutrient partitioner in terms of reducing blood glucose response to a meal (it does this by increasing glucose disposal into target tissues). While I think it is a good idea to consume ALA if your insulin sensitivity is poor (again as diagnosed by a 3 hour blood glucose tolerance test), if your insulin sensitivity is normal to good, it's probably unnecessary.
Furthermore, as indicated above, the post-workout period is marked by excellent insulin sensitivity. Therefore ALA will probably have very little additional effect during the post workout period. It's a matter of redundant systems. It's kind of like pushing your gas pedal to the floor. When the car is going as fast as it can go, another gas pedal isn't going to do anything but waste gas.
[ Q ] Thanks for taking the time to share some of your knowledge with us, John.
No problem, my pleasure.