When to eat before a workout to avoid the insulin/sugar crash

How long before a workout is it best to eat sugar or fast burning carbs to avoid the insulin spike and sugar crash?

I got it wrong the other day with a workout about 45 mins after a huge lump of birthday cake and sat there sweating and feeling dizzy before giving up, and going back for more cake…


I’d get to a doctor. Aside from cake not being healthy for you, I’ve not once felt like that after ingestion of a product full of bs chemicals and sugar. I’m a pig, and love said bs chemical/sugar goodness :smiley:
To further answer your question, I typically workout fasted. Two each is own, you’ll have to find what works for you. Seriously though, go see a doc

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Generally it’s 3-4 hours eating a proper meal to allow blood sugars to return to normal and allow your body to process the food. However this will depend on the individual, the type/intensity of the workout and the food eaten. Cake :birthday: before intensity is probably not the best way to go. I’m not sure if anyone has studied the affects of cake as pre-ride nutrition. However based on your n=1 experience it appears more research is needed :wink:.

I’d hazard a guess it’s something to do with your digestion rather than the simple sugars. Just think how many times we take a gel or energy drink/cake/coffee stop and don’t suffer on the bike.
Could just be the stodgy goodness staying heavy in your stomach

You’ve been running a calorie deficit and got a big blood sugar spike beyond normal levels I’m guessing. Quite common.

If this is the case then avoid sugary foods while cutting weight unless it’s during the workout, can cheat there, or immediately post workout.

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No, it was just a standard blood sugar dip. I never eat sugar unless it’s a gel, bar or drink in a workout or race context, so I am more sensitive to sugar spikes than most people maybe. It was after work so i probably was running low on energy anyway.

The original question was about how to time a pre-race gel (or something like sugar) so i didn’t get the insulin hit, before the exercise started and the insulin response becomes blunted, so that blood sugar doesn’t get reduced just when you need it.

Many times, coach Chad has recommended something like 5 minutes before. His example was to take a gel after your warm-up while on the start line. He also said that 1 hour before is probably the worst time.

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Yes, 45mins would be a disaster for me, 10 mins max I’d say.

I concur that I’ve heard the one hour mark discouraged a lot. I’ll add as my N=1 that I’ll often eat about an hour before I get on the bike, typically as that’s what my schedule allows on some days. Usually carb focused, if I’m planning anything sweet spot or higher. I’ve never had a problem with it. There’s a lot of individual variability here, its important to figure out what works for you.

If the goal is to not let your blood sugar decline prior to the ride, eat 2+ hours in advance, and/or just before.

I regularly eat a bar or something else solid about an hour before a multi hour race. I won’t have anything super fast (gel) at that time frame but will have a gel on the start line. For me the need to get ahead of the caloric burn of road racing, as well as the typical lack of intensity in the first 30-45 minutes of a race, means I can get away with starting my digestion processes on this time frame.

For hard interval sessions I’ll have some slower carbs in the 30 minutes leading up to a session - maybe a sweet potato or a small bowl of cereal and then have a gel after the warm-up or maybe the first or second set of intervals if I think I’ll be going really deep

Longer sweet spot or endurance workouts I tend to not fuel beforehand and just eat during as needed, but slower carbs like fruits