I’m a 58, almost 59 year old cyclist who has been practicing a low carb/high fat diet for four weeks. This winter I’ve trained mostly on an indoor trainer keeping a low to moderate level of efforts - and have done fine using fat as fuel. The weather here in Michigan broke for a bit so I recently rode outdoors on a very demanding, hilly route. During this outdoor ride the second large hill I encountered, where my heart rate elevated over 170, I immediately bonked and had to walk, (keep in mind years prior I’ve logged 4500 - 5000 miles per year on a bike and never walked due to exhaustion). I new I had 18 more miles to go to complete this particular ride. The fascinating thing was every hill I would encounter, (and there were many) I walked a little less and by the time I had finished the 22 mile route I was able to ride up each punchy hill, (slowly, but able to ride), It was as if I could actually see/feel my body adapting and using fat as fuel at increasing intensities. The bonk actually went backwards during this ride - hit the wall at the beginning yet performance slightly improved as the miles went by. It was something I had never experienced before. I have a lot of training to do to get my performance/speed back up ... but at least I know it’s possible. Your one chart that showed carb depletion after intense exercise in athletes, (different levels of fat adapted athletes) reenforced my thoughts on this. Great information you’ve provided.
Keep it up. I've been low carb for just over a year now. It's wonderful. People talk "weight loss" I used a body fat scale to track my progress. Of the 58 lbs I lost, only 3 lbs were "lean". I'm far stronger now. I bounce around the house like a kid... In addition to low carb, I'm exceedingly leery of seed oils (corn, soy and heat damaged canola).... The research is still mixed on PUFAs in general, but I'm leaning towards avoiding them for now. Ditto pretty much anything "new" or "artificial" or in a bag or box.
@Robert Goodnoe, I had the exact same experience as a teenager, maybe 15. I was training to run a marathon. I was fit and strong but had no idea what I was doing. It turns out no one did in that era (around the late 1970s). I went out for a long run, a 20 miler. It was a single loop on the NE side of Melbourne, pretty remote in those days. I took no food or water. Well, I totally bonked at about 12 miles. I was walking and all I could think about was eating ice cream. I walked maybe 2 miles, then started running. The further I ran, the better I felt. Apparently my body made a transition over to fat or liver started making ketones, or something. I finished the last 3 miles very strongly running as fast as I ever have over a sustained period. It was strange but exhilarating. I searched for that same feeling for years after but never found it again. For the next 2 decades endurance performance was all about carbohydrates.
@@martinirving3824 Wow, that is fascinating. i think it really must pertain to the idea that you just have to go through the whole complete glycogen/ glucose depletion thing rough though it is.. then enforced fuel partitioning happens (??). If you'd had that ice cream im guessing it likely wouldnt have happened. Im trying to be patient now adapting.. its uncomfortable lol.
A small hint for you, when you are fueled by carbs, you load up on carbs before you ride. When you are fueled by fat, load up on fat before you ride. It takes a bit longer for fat to break down when starting exercise. This is the warm up. You can overcome that period by starting with a fat drink roughly an hour before the ride so you get fat already circulating in your blood when you start.
That's awesome for only being 4 weeks into the process. As he said, you can be in ketosis but full keto adaptation can take much longer. My comment is late and you're probably crushing it now!
35 days in after I changed life style 180 degrees. carnivore diet, eat once a day and done two 48 hour fast. Feel grat and all my Undefined health issues is almost gone...But I am worried on my Ketone levels.... Ketones after 14 days started to show 4-5 mmol/L but sometimes spike to 7-8 and once to 8.7 mmol/L. my understanding is that unless Glucose is high this is ok ? My Glucose was 3.4 mmol/L when Ketones was 8.7 mmol/L.
I don’t agree with his evolutionary take on ketosis. Not every low carb tribe or group goes into ketosis. The Inuit and Maasai have evolved to resist ketosis as an adaption to starvation. So while I can certainly see applications for a low carb or Leto diet I believe his evolutionary perspective is off.
I love how no ketogenic studies have actually shown a performance BENEFIT. "keto athletes burn more fat!" As if there's a prize for who burnt the most fat during the race. No, the person who WINS the race eats a LOT of carbs. If you want proper data on how proper athletes eat to perform, look up Louise Burke, Trent Stellingwerff, and others in the area.
You're right, to be the best fat burner in the world doesn't win you anything. But for sports more on the endurance end of the scale than the high intensity one, fat as fuel has more benefits than drawbacks. With high intensity it is a little more difficult since there the nervous system load has a big influence. More carbs but maybe still in the low carb range, maybe not the keto range seems to bring more performance. But those are all N=1 stories AFAIK. So for benefits, again, AFAIK, there is no proof that a high carb athlete is better fuelled than a fully adapted low carb athlete.
People seem to think that when carbs are in the system, no fat is being burned. Athletes who eat carbs burn plenty of fat as well. The body prefers glucose so much that it will convert protein~ even if it has to break down muscle to get it. Keto is a handy survival mechanism, but it’s benefits are overblown. Primitive human diets were rarely ketogenic. They ate too much protein.
@@Subtlenimbus Ketosis is not really about athletic performance but it works pretty well too. Your claim that the body prefers glucose is an unproven assumption. Most tissues are happy to take either glucose, free fatty acids or ketones. Many primitive diets were actually low carb as there were no grains in them. The amount of protein differs but it was never extremely high except for example Inuit. It is however proven that the fat cells don't give up the fat when there is insulin present. The main reason to remain in the ketosis range is to be able to got into fasting mode when you stop eating. Just reducing calories does actually break down the muscle protein when the carbs run out. When you are fat-adapted you do not have that long-time span going from glucose to ketones in which you burn muscle protein. And yes, when you eat fat and protein then that protein will also produce some glucose but it will be used to build muscle as well. Which is why loosing fat and building muscle at the same time does not really work well. You are either anabolic or catabolic based on your insulin and glucagon levels. But you can do your muscle building exercise and then eat enough fat and protein and you will slip out of ketosis to build the muscle overnight but then you get back into it and burn fat in the morning during exercise. Surely if you are looking for extreme muscle growth you won't burn any fat. The science is pretty convincing and it works perfectly for me. A while ago it first reversed my beginning diabetes T2 and got rid of my arthritis and then I lost a lot of weight so I had to restart the muscle building process.
Whelp, As a fat adapted athlete I can point to a few things. Metabolic flexibility to use both carbs and fat as fuel; as glycogen is depleted switching to fat allows for a 'bonk-less' activity in high endurance activity. Marathons, ultras, Ocr races....no need to use fuels or gels. A much more consistent and readily available fuel source, even with low body fat. Fat adapted energy bursts that kick in at 40/50 mins, typically at the time of glycogen depletion is a feeling that puts any pre workout or other stimulant to shame.