I’m baffled by the concept of carb depletion. Maybe somebody can help me out with this one.
It seems intuitive that as we work out, the carbs (glycogen?) in our muscles and blood gets used up. Sure, this seems logical. But has anyone actually experienced carb-depletion in the gym? I mean is there a point at which you cannot continue? I remember in highschool, I would put in 1-1.5 hours of heavy compound lifting, or 3 hours of circuit training for baseball every day (usually on an empty stomach) and I always had the energy (if not the gumption) to do at least 1 more set. Aren’t you semi-indefinitely able to do more?
So, assuming that CD does exist, what about the large-yet-undefined crowd that guzzles a soda mid-workout to battle carb-depletion? I mean, EATING OR DRINKING DURING A WORKOUT! I know plenty of people do this, and I think this site has promoted it on occasion, but it doesn’t seem very pragmatic.
For one, it takes about 30-45 minutes for anything you eat to hit the bloodstream (maybe less for liquid.) Now, consider you are training heavy, and you have triggered your parasympathetic nervous response. NOW how long will it take to digest something? A few hours? Is that power-dose of carbs really doing anything during the workout? I would argue that it is not.
I believe in proper pre and post-workout nutrition, don’t get me wrong. But can somebody enlighten me on why you would consume nutrients mid-workout?
Eating or drinking something immediately pre or during your workout would in theory trigger an almost immediate insulin response in a highly insulin sensitive person. As we know, insulin is a crazy bitch of a hormone in that it is almost always bad for us UNLESS we are working out, in which case it is highly anabolic. Basically insulin signals the body to store things.
When your not working out, that means fat, but in the middle of a long workout it would tell your body to start building muscle. In actuality, your body cannot really start storing until your done breaking it down,i.e. finished working out. So, drinking an insulin inducing drink halfway through your workout would mean you get that surge at the end of your workout when you need to start building muscle.
As for the carb depletion, I have personally never seen someone drink a soda during a workout, but something like a gatorade is more likely. Gatorade and other drinks were developed for high level college and professional athletes and contain a ton of carbs and electrolytes meant to replenish the liters of sweat you would lose working out intensely.
Since not many of us work out at the Gator Bowl in the Florida heat, many of us do not need all of these extra electrolytes, but would be better suited to oh i dont know, eat a banana at breakfast.
Carb depletion would take more than one workout to achieve. Consider: proponants of CD advise dropping carb intake to very low levels for a week or more, while still training. Also consider that the liver can store around 2000Cal of carbs (~500g) if your going to CD you need to empty the whole biological system.
Intake of carb drinks is routine in endurance events lasting over an hour, and proven effective too. Fluid intake is rapidly absorbed (i.e. does not take 30-45mins).
I have spoken to a couple of body builders (local level)who have intentionally carb depleted, with the aim of super-compensating and achieving a fuller muscled look. They describe they training as “Hell”
There are different levels of carb depletion. Yes you can do another rep or another set but that doesn’t mean your muscles are fully carb loaded. If your max is 315 and you did it once, rested for 3 minutes and couldn’t do it again, your muscles are carb depleted just not completely. That and you probably have little microtears.
Which goes into the second point that there are thousands of variables to look at when looking at real life situations involving the body. Studies and educational resources need to simplify things so they describe one system, but when your applying the knowlege you have to take into account all the systems that come into play.
So for mid-workout nutrition you have two uses. One for the person that is just trying to get bigger, they want to take advantage of their body’s hormone response to quicker storage of protein as well as protein synthesis.
For athletes, and gym rats, 30-45 minutes is nothing and they want the best possible performance after an hour or so working out. Like I said before just because your not completely depleted doesn’t mean they are fully loaded. The better you can perform after an hour the better you can train your body.
I did Lyle McDonald’s extremely effective Ultimate Diet 2.0. It’s a cyclical ketogenic diet and carb depeletion is actually the goal of the first half of your weekly training sessions on this diet. You actually have to bust ass to fully depleat yourself of glycogen, utilizing extremely long time under tension for your sets. However, training under carb depletion is seriously the most miserable thing I can think of right now.
Actually, there’s not a lot of glycogen depletion that occurs during a single workout. If your max is 315 and you do it, and can’t do it again 5 minutes later, it’s more likely phosphagen depletion that’s holding you back, in addition to plain old fatigue.