I’ve been keto for about a month. I am a fitness instructor teaching about 8-10 hardcore classes a week (I participate in all my classes) and a full marathon runner – a few weeks into training for my next race. I’m 39, 5’5″ and about 138lbs. I didn’t necessarily go into this diet with the intention of losing weight, I was more intrigued by the ability to function on my own fat supply and not need as many carbs to do it. It seemed ok at the beginning, but lately, I’m so fatigued during my workouts and long (and even the short) runs. I feel slow and sluggish and drained, barely able to get through 3 classes and a run in a day (which I could do on a carb diet). I’m still on the fence about whether or not this is good for endurance athletes. Seems like there’s not much in the way of research for endurance athletes online and the things that I have found are a mixed bag. Is there anyone on here who has the same kind of lifestyle as me and has found success? I really want this to work, but I’m struggling. Any advice or guidance would be greatly appreciated.
Give yourself some more time, it is absolutely worth it. With regard to your other question, from memory it’s Brad Kearns and Mark Sisson who are successful keto endurance athletes. Actually I’m sure there are others that have been interviewed on the podcast too, but the names escape me at this moment. I’d suggest starting there for more advice about your specific training needs.
You could eat 500 calories a day
And that meal could be 75% fat 20 % protein
But it wouldn’t be adequate for you calorically
So focus on grams
0-20 grams carbs
You could Start at 70 grams protein
The rest of your calories up to and exceeding your TDEE will come from fat grams
140 grams plus +++++
I’m guessing your issue is a combo of low calorie
And not yet being fat adapted
Your mitochondria are learning to efficiently make ATP from fatty acids. It takes time for them to re-tool. They’re used to cheap sugar. Stick it out until you’re keto adapted and you’ll learn why metabolic flexibility is such a game changer.
You might not be eating enough fat, you haven’t fat adapted yet so your body is still trying to fuel from carbs vs fat once you become fat adapted you’ll be able to perform better than you ever did. Try putting a pinch of Himalayan salt under your tongue to help prior to working out it can also be lack of electrolytes.