Originally Posted by
bblair
Q: can a person actually become "adapted" or is this simply physiology?
Q2: Would not an athlete who is termed "adapted" also be a fitter person, thus being stronger, faster, etc.?
People absolutely do become adapted.. that has been shown in several studies.. 100%!
This study (link below) was a "cross-over" study... so each person's ability to metabolize fat was essentially a control on themselves.. each participant did BOTH diets with a washout period between and the differences were VERY apparent... previous studies that did less that 4weeks adaptation didn't show these results.. so in addition to the higher cross over point and the higher fat metabolism ratef or those "fat adapted".. this and other studies show there is adatation that happens over some period... minimally 4 weeks..
Half the group did a keto diet (HF) for one month.. other half did high carb diet (HC) for one month... both continued to train.. then there was a washout period.. then they switched and the group that had done HF did HC and group that had done HC did the HF.
Originally Posted by
bblair
Q3: Bonus question. If I am both fat and carb "adapted" before that was what, protein adapted? That is all that is left.
Fat and carbs are used as fuel.. protein can be converted to glucose, but only if you are is a starvation state... eating carbs raises insulin and insulin inhibits you body from buring body fat. when you cut out or dramatically lower carbs.. your bodys is now able to use your body fat as fuel and if you maintain this for seems like 4 weeks is the minimum you body starts to up regulate a bunch of enzymes and pathways that allow for faster, more efficient metabolism of fat.. our bodies are very efficient.. not going to produce a bunch of enzymes etc when you never use them 🤷🏾♂️
Originally Posted by
bblair
OK, one more. According to my recent VO2 Max test, I switch from burning fat to carbs around 85% of my max HR. So, right around there is where I should train, right? According to the analysis that I was given, that is Zone 2, but in all honest, that is too high for me to sustain over a long period.
This is not how the body work.. you don't "switch" from fats to carbs.. sitting on your sofa watching Netflix yout body is using carbs as fuel. The crossover point is when more than 50% of your energy starts to come from carbs. So when you are in zone 1 and 2 a smaller portion of the energy comes from carbs.. but you ARE still using carbs in zone 1 and 2.. every zone! When you are in zone 5 & 6.. you are using a ton of fats.. just that more then 50% of your energy is coming from carbs... THERE IS NO SWITCH FROM FAT TO CARBS.. doesn't exist.. it's all a continum.
Edit: that Z2 was from my actual test. RWGPS calculates that as a Zone 4 HR, which fits better with my perceived rate of exertion or whatever that is called.[/QUOTE]
**So this is link to the actual study of the 6x800 study that yeilded the 85% crossover and the as high as 8.5g/min on keto diet.. so you can see study design.. the other link I provided was analysis of this study in comparison to previous studies that didn't allow
Low and high carbohydrate isocaloric diets on performance, fat oxidation, glucose and cardiometabolic health in middle age males