Carbohydrate Loading

This post is adapted from Nutrition for Cyclists: Eating and Drinking Before, During, and After the Ride, a forthcoming ebook which I will be publishing for Kindle on Amazon.com.

Nutrition for Cyclists: Eating and Drinking Before, During and After the Ride can now be purchased on Amazon.com.  For information about the book and how it relates to what I’ve posted to Tuned In To Cycling, please check out this post.

eating spaghettiWell-organized and popular century rides often offer an all-you-can-eat pasta dinner the night before the ride.  If you go to the dinner, you’re likely to see people putting away enormous plates of pasta and if you ask them why they’re eating so much spaghetti they’ll tell you that they’re carbo loading for the next day’s ride.  What is carbohydrate loading and is eating a lot of spaghetti the night before a big ride the right way to go about it?

The basic idea behind carbohydrate loading is that glycogen stores in the muscles and liver can be increased over the norm by following specific exercise and dietary regimens in the days before a ride.  The increased glycogen stores should then translate into a longer time before fatigue sets in due to glycogen depletion during the ride. There are three recognized carbohydrate loading methods and I will suggest an alternative approach.

The original and most severe method follows a week-long regimen. On the 7th day before the ride, you exercise to exhaustion.  This exercise bout should last a minimum of 90 minutes.  The next 3 days are a carbohydrate depletion phase during which you train lightly while keeping carbohydrate intake at only 10% of your daily caloric intake.  The final 3 days before the big ride are a carbohydrate loading phase.  You continue to train lightly while jacking carbohydrate intake up to 70% of your daily caloric intake.  It’s important not to increase your total caloric intake from the norm over the 6 days of carbohydrate depletion and loading.  During the 3 day depletion phase you replace calories normally consumed in carbohydrates with calories consumed in fats and proteins. During the 3 day loading phase your replace fats and proteins with carbohydrates.

drink-b4-thirsty-mod-4-customThink about this for a minute.  The depletion phase is an extended period of controlled hypoglycemia, essentially a 3 day bonk.  During that time you can be expected to experience all of the negative effects of bonking including weakness and lethargy, anxiety, depression, hostility, feelings of hopelessness and failure, low levels of emotional control, reduced awareness of your surroundings and confused thinking.  In addition, the immune system will be depressed and you will be more susceptible to contracting an illness that may still be present when the ride comes several days later.

A 3 day bonk is hard.  Very hard.  The second method eliminates the bonk by eliminating the depletion phase. On the 7th day before the ride you have a long exercise session but you don’t exercise to exhaustion.  For the next 6 days you engage in progressively lighter exercise sessions each day.  Some people recommend tapering the level of exercise down to a day of rest on the 6th day.  For the first half of this 6 day period you ingest carbohydrates at a normal 55% – 60% of your daily caloric intake.  For the final 3 days you ramp carbohydrate intake up to 70% of your daily caloric intake, again by replacing fats and protein with carbs.

The third method is the easiest of the three. During the week before the big ride you exercise lightly and eat normally.  On the day before the ride you do a very short, 3 minute high intensity workout.  The workout should be made up of a 2.5 minute session at 130% VO2 max which is roughly equivalent to the fastest pace you can maintain over approximately 4 minutes of all-out running or cycling.  Follow this 2.5 minute effort with a 30 second flat-out sprint.  If done properly, this 3 minute workout is going to hurt.  During the following 24 hours ingest 12 grams of carbohydrates per kilogram of lean muscle mass.  Muscle mass can vary greatly depending on age, gender and degree of muscular development.  Based on a very rough average of 35% muscle mass for men and 27% muscle mass for women the carbohydrate intake over the 24 hour period would total approximately 305 grams for a 160 lb. male and 191 grams for a 130 lb. female.

If followed correctly, all three of these methods should produce a markedly enhanced level of glycogen storage on the day of the big ride.  Neither anecdotal reports (which are basically worthless) nor research studies have reached a clear consensus on how much better or worse one method is relative to the others.  The bottom line is that all three methods are effective if followed properly.

baby spaghetti dumpNow, I’ll suggest a fourth method that is usually not discussed in the literature.  Forget about it. Don’t bother with any of this stuff.

Wait . . . what? Consider the kind of riding you do.

If your ride takes less than 90 minutes, carbohydrate loading is a non-issue because proper eating before, during and after your previous ride should have adequately prepared you for the next ride.

If your ride takes longer than 2.5 or 3 hours, you’re going to have to eat during the ride anyway because even perfectly executed carbohydrate loading isn’t going to provide you with sufficient glycogen stores to last for this length of time.  All carbohydrate loading is doing is delaying the time before you have to start eating.

Wiggins eating_croppedIf your ride takes between 1.5 and and 2, maybe 2.5 hours, carbohydrate loading might allow you to get through the ride without ingesting any carbohydrates. But why would you want to do this? If you enjoy rides that last more than 90 minutes you would be much better served by becoming proficient at eating on the bike to fully supply your nutritional needs during the ride. You get better at what you practice and if you find a way to avoid eating on the bike, you’re not going to get better at eating on the bike.

The fundamental goal of cycling nutrition is to provide full nutritional support for your ride.  A competitive race, a long organized or training ride, and a Sunday afternoon toodle around the neighborhood all make different demands on your body but whatever the ride, you will do it better and enjoy it more if you provide the nutritional support the ride needs.  The simplest and most effective way to do this is to develop the habit of ingesting small amounts of carbohydrate regularly during the ride.  The best way to develop the habit is to practice doing it.

If properly carried out, carbohydrate loading can fully support rides lasting 1.5 to 2 hours, maybe a bit more, if you don’t ingest any other carbohydrates during the ride. It’s not much use for rides lasting less than 90 minutes or more than 2, maybe 2.5 hours.  Eating properly during the ride can fully support any kind of ride you want to do. The choice is yours.