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Pre-Workout Nutrition: Carbs vs Fat?


#1

If you were to eat 300g of carbs most in the form of sugar and did a hard conditioning session on the rower 10-15 minutes later would your body use the carbs you just ate as fuel? What would happen if instead of carbs you ate something higher in fat like cheeseburgers/Pizza?


#2

It would slow down digestion of the carbs. Meadows is one guy at least who likes to add some fat pre-workout for that reason. But at some point you are just going to end up with a bunch of heavy food sitting in your stomach. I don’t know that fat by itself is particularly good pre-workout. Your body already contains more fat that it could ever burn in a workout.


#3

-So, the body would use the sugar immediately for fuel, fat would just slow it down or the hard conditioning would?

-But, how would the body respond to a mostly protein/fat meal?Would it leave it alone and use the stored glycogen or would it be a mix?

EDIT: The title of the thread was changed by the Mods. It now seems like I am asking which is better. I just wanted to know how the body would respond in terms of burning calories for fuel.


#4

First, everyone is going to be different. Second, it probably depends largely on what you are used to as well as things like your insulin sensitivity and general health. Protein by itself is actually fairly effective at replenishing glycogen. It will probably also have varying effects on nervous system activation. I’m personally not a fan of pre-workout calories of any kind for that reason.

Bottom line is, no one can tell you what will work for you. Try whatever you want and see how your workouts are, and how your strength and body composition respond (you’ll have to give it some decent time). If it works, keep doing it, if it doesn’t then stop.


#5

Say you wake up at 7 am eat a box of kids cereal, 20 minutes later you run 10 miles, will your body not use the sugar you just ate regardless of "what you are used to"? Is that not what marathon, cyclists do, eat fast acting carbs to be used immediately?


#6

It is not that simple. Fat tissue is in constant flux regardless, it isn't just a storage tank. There are hundreds of simultaneous processes for both absorbing and using energy. If you are diabetic you might spike your blood sugar, spike your insulin, absorb very little, and pee out a bunch of sugar.

20 minutes later, your insulin is already going to be elevated and you'll be favoring storing the glucose in fat tissue before you start running. The body is an insanely complex machine, you can't think of it as a single lever.


#7

Can we get @chris_collucci in here?


#8

There other variables to consider. How close to the workout are you eating? What kind of carbs?

Which do you use?

This basically tells you intense activity uses a lot of carbs and light intensities will burn mostly fat during the activity. You will likely not be using anything you ate within 2 hours of working out as it takes that much time or more for nutrients to even get to the small intestine.

plus 300 g of carbs seems like overkill for a 15 minute workout.


#9

"You will likely not be using anything you ate within 2 hours of working out " then why do endurance athletes eat gel packs during the activity?


#10

Because some ultra-endurance and sporting events last 2 hours or more and those packs are useful in those instances.

But the main reason people use them is because some brilliant marketer told them that marathoners use them so they must help all endurance athletes.