banana's every day, good or bad?

Post-Workout Carbs
What's The Best Choice?


As many of you know, there are really only two times of the day to take in simple carbohydrates: first thing in the morning and after your workout.

First thing in the morning because you are coming off a "fast" - which is how ever long you slept the night before. So, at that time you want a simple carbohydrate source and a quick digesting protein source. Now, if you plan on doing morning cardio, skip the carbs and have a small protein shake, then when you do your cardio you will be burning mostly fat for fuel. When you're done, have your carbs and protein.

After the workout is the other time to take in simple carbs: this is critical because it starts the whole recovery/muscle growth process. Following a hard workout, your body is severely depleted of glycogen and glucose.

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Following A Hard Workout,
Your Body Is Severely Depleted.

During the workout hard working muscles use glucose (usable energy) and glycogen (stored energy) for energy. As such, there is a point at which blood glucose levels (available energy) and glycogen levels (stored energy) get so low that intense exercise can't continue. There just isn't enough available energy for your muscles to use.

So what happens is that the hormone cortisol is secreted, this is your body's "stress" hormone and it has very catabolic effects. What cortisol does is eat up muscle tissue for protein and convert it into glucose. A process called gluconeogenesis ensues, producing glucose from these amino acids in the liver. The net result is a loss of muscle tissue.


The Implications Of Cortisol Release!
Cortisol is termed catabolic as it has the opposite effect to testosterone, insulin and growth hormone in that it breaks down tissue.

The post-workout shake prevents this. It also allows insulin to be released, this is, as most of you know, one of several anabolic hormones in the body (if you are a natural trainer especially, you want to maximize the release of all your body's anabolic hormones through all available methods).

So, whey protein is your best protein source at this time because it is absorbed quickly, what is the best carbohydrate source? Well, we want a high glycemic carbohydrate source. This term refers to carbs that are high on the glycemic index (70 and above rates as high).

The Glycemic Index is a measure of how quickly a food raises blood sugar and hence insulin levels. Normally, it is best to eat lower glycemic foods so as not to initiate an insulin spike (55 and under rates as low). But post-workout, the exact opposite is true.


It is critical to get the carbs (and protein) to the muscle cells as fast as possible. As well, the elevated insulin levels will help to drive nutrients into the muscle cells. And again, high-glycemic carbs are best for this purpose.

The postexercise "anabolic window" is a highly misused & abused concept. Preworkout nutrition all but cancels the urgency, unless you're an endurance athlete with multiple glycogen-depleting events in a single day. Getting down to brass tacks, a relatively recent study (Power et al. 2009) showed that a 45g dose of whey protein isolate takes appx 50 minutes to cause blood AA levels to peak. Resulting insulin levels, which peaked at 40 minutes after ingestion, remained at elevations known to max out the inhibition of muscle protein breakdown (15-30 mU/L) for 120 minutes after ingestion. This dose takes 3 hours for insulin & AA levels to return to baseline from the point of ingestion. The inclusion of carbs to this dose would cause AA & insulin levels to peak higher & stay elevated above baseline even longer.

So much for the anabolic peephole & the urgency to down AAs during your weight training workout; they are already seeping into circulation (& will continue to do so after your training bout is done). Even in the event that a preworkout meal is skipped, the anabolic effect of the postworkout meal is increased as a supercompensatory response (Deldicque et al, 2010). Moving on, another recent study (Staples et al, 2010) found that a substantial dose of carbohydrate (50g maltodextrin) added to 25g whey protein was unable to further increase postexercise net muscle protein balance compared to the protein dose without carbs. Again, this is not to say that adding carbs at this point is counterproductive, but it certainly doesn't support the idea that you must get your lightning-fast postexercise carb orgy for optimal results.

To add to this... Why has the majority of longer-term research failed to show any meaningful differences in nutrient timing relative to the resistance training bout? It's likely because the body is smarter than we give it credit for. Most people don't know that as a result of a single training bout, the receptivity of muscle to protein dosing can persist for at least 24 hours: http://www.ncbi.nlm.nih.gov/pubmed/21289204

Here's what you're not seeming to grasp: the "windows" for taking advantage of nutrient timing are not little peepholes. They're more like bay windows of a mansion. You're ignoring just how long the anabolic effects are of a typical mixed meal. Depending on the size of a meal, it takes a good 1-2 hours for circulating substrate levels to peak, and it takes a good 3-6 hours (or more) for everythng to drop back down to baseline.

You're also ignoring the fact that the anabolic effects of a meal are maxed out at much lower levels than typical meals drive insulin & amino acids up to. Furthermore, you're also ignoring the body's ability of anabolic (& fat-oxidative) supercompensation when forced to work in the absence of fuels. So, metaphorically speaking, our physiology basically has the universe mapped out and you're thinking it needs to be taught addition & subtraction.