I hope this thread won't generate heated conflict. It's simply a report on my experiment yesterday with riding an unsupported metric century, and eating no carbohydrates before or during the ride.
The basic theory here is that people who are "fat-adapted" can burn fat more efficiently, and don't need to rely on carbs during exercise.
What Does it Mean to Be Fat-Adapted? | Mark's Daily Apple
Since I've eaten low-carb for four years, I should be pretty "fat-adapted." Just for fun, I thought I'd do a ride with zero carbs. I didn't expect much of a difference between this ride and my normal rides, because I usually don't each much carb food during a ride.
Here's what I ate on a normal ride last week:
Breakfast (6 AM): 1 egg, one bacon, 1/2 avocado.
Pre-ride (10 AM ): 1 egg and 1 slice of cheese, coffee with 2 TBS heavy whipping cream.
During the Ride: 120 grams of almonds, macadamias, and pecans, liberally coated with electrolytes (NaCl, KCl, Calcium Citrate, Magnesium Citrate). One Quest bar, one cup coffee with 2 TBS half-and-half.
Total digestible carbohydrate: approximately 15 grams
Here's what I ate on yesterday's ride:
Dinner, night before: Hamburger patty with sugar-free ketchup and sugar-free mayo, 1 glass of wine
Breakfast (6 AM): 1 egg, 1 sausage
Pre-ride (10 AM ): 1 egg, black coffee with 2 TBS MCT oil.
During the Ride: 1 Aidell's Bacon, Mushroom, Swiss Cheese sausage (96 grams), 1/4 hamburger patty, 1 black coffee.
Total digestible carbohydrate: approximately 0 grams.
Note that I didn't eat the sausage necessarily for fuel, but mainly because I didn't want to feel hungry.
I felt a bit more tired that usual towards the end of the ride. My energy on these standard rides varies quite a bit from one ride to the next, but on this ride, my energy was on the low end of the range.
However, my perception of tiredness was strongly influenced by feeling like I was going to barf. That's right, the sausage tasted great, but it was a big mistake. Combined with the black coffee, this really made me nauseous.
My average moving speed was 12.3 MPH for the normal ride, and 12.1 MPH for the zero-carb ride.
Here are the charts for the zero-carb ride:
And here is a comparison with a recent ride:
The laps in the red rectangle are the hill climb.