Originally Posted by
rubiksoval
The deal is your body needs carbohydrates to ride at any type of intensity.
If your goal is to plod around as slowly as possible for random amounts of time, low carb/keto may suffice.
If your goal is to actually go out and push a little bit on the pedals, you need some carbohydrates. It's about as basic a nutrition/metabolism issue as there is, and yet threads like these still pop up because people buy into these ridiculous premises that are either completely fabricated or heavily misleading.
This is true if one has relied on eating carbohydrates as a primary macronutrient, which most humans do. But if you don't eat carbs, your body will upregulate liver gluconeogenesis enzymes that converts glycerol(the 3 carbon backbone molecule of triglycerides(fat molecule)) in to glucose. It will also up regulate lactate shuttle enzymes that can convert lactate back into sugar when your lactate production outpaces glucose burn. Glucose is vital for high intensity physical effort. The thing is the body does an amazing job producing glucose in the liver. You don't have to consume it.
But look no further at the amazing physical feats that a cheetah(or any animal in nature for that matter) can do without carb loading. They aren't sluggish. Would you rather be chased by a lion that were well fed or hadn't eating in 5 days? While their bone and muscle structures aren't the same as a primate, their ATP(energy molecule) generation is the same. It's just that humans mastered fire/farming about 10k years ago and eating carbs pulled us away from our natural physiologic state.
I'm not trying to demonize carbs and convert people into the "keto" cult. Carb load all you want. That's fine with me. But if one is curious about the biochemical physiology between glucose, sugar, and ketones it's quite fascinating. Why not understand it something that is occurring in all of us from the day we are in utero till the day we die.