How Do You Know You’re in Zone 2? Finding the Right Training Intensity Without a Wearable | Inigo San Milan | Be Well Moments

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0:10So when we think about Zone 2, and tell me if I'm wrong, but I always think about Zone 2 in training, that I can just about talk but not in a comfortable way. How can someone understand, if they don't have a wearable, how can they understand where Zone 2 is? Yeah, that's a good question. And this is about it. And it resembles closely to what we see in the laboratory when we establish the parameters for that zone two and the rest of the zones, right? Yes, that's an intensity where definitely we cannot keep this conversation. This would be resting as we are. But it's a conversation that you can sustain.

0:52I mean, you can sustain, but it takes an effort, right? It's a forced conversation that you have to breathe, you have to talk, but you can't sustain it with an effort. If you can't sustain, if you cannot sustain that conversation for more than a few seconds, you're already in very high intensity. And this is due to glycolysis, which is another event that you see very well in the laboratory. When you're working in zone two, you're burning glucose, but you're burning fat. and that's the intensity of the one you burn the most fat, which is another concept now getting very popular, which is the fat max, right?

1:35That's intensity of the one you burn the most fat. I've been using that concept for 25 years at least and using it for weight loss purposes too. People would come to the laboratory because they've been trying to lose weight through exercise and they can't. And then when you do the test, you see that they've been exercising too high intensities where you burn zero fat. And you show that to them because in the laboratory, you see very well where you burn the fat, you see the grams per minute, the fat oxidation and grams per minute and carbohydrate oxidation. So they get to a point that you get to your fat max.

2:14And then as exercise intensity increases, the fat disappears and you would burn zero fat and why is that is because as you go on to a higher exercise intensities the the cells the muscles need a faster atp faster energy and that energy cannot be supplied by fat anymore because while fat can give you more overall energy it's slower it's like a diesel gasoline right it's lower way it takes more time to give you that energy which when you're at lower intensity is great right this is part of the evolution right of humans because we can only store about half a kilo 500 grams like two pounds of glycogen no one pound of glycogen sorry which is how we store glucose carbohydrates right so the body tends to preserve that tank very well and for that starts using other fuels mainly fat right but when exercise intensity is very high fat cannot be cannot give you energy fast enough and you need to switch to carbohydrates and then and sorry i've been going the long way this is what happens is like a you suppress fat and this is why a lot of people were not burning fat because they were always in in carbohydrate burning they were not burning adipose tissue but then through the talk test to your point the fact you're speaking fast is because you're burning a lot of carbohydrates you're producing a lot of lactate and you start buffering that lactate and that co2 that's part of producing of buffering the lactate and that forces you to breathe faster right so when you're breathing faster, you're at a higher metabolic stress and you start decreasing significantly the amount of fat burning.

4:12So when you can't stop at all, when you can't speak at all, you're not burning fat, you're burning glucose. Wow. Okay. So sometimes people might just be doing too much high intensity and that's why they're not losing any weight. Yes. We've been knowing that for decades as well in working with athletes. I don't think that's a normal conception in the public. I think a lot of people today will go to the gym to want to sweat and burn a lot of energy and wonder why they're not losing weight. And this is the exact reason why. So you're saying if they can balance that with more zone two and recovery, their mitochondrial health will improve.

4:48Yes. Yes, it pays off. People would say, of course, yeah, but if you do high intensity, you increase your basal metabolic rate and you burn fat down the road in the next 6 12 24 hours sure of course you can do that of course but why not burning fat while you're exercising so they instead of burning fat after you exercise relying on what you think that you're going to be burning at rest because of the high intensity that you did right i think there's room for both concepts obviously yeah but again why not burning fat during exercise because you're going to burn in more fat during exercise you burn it depends right uh but you depend it depends on your fitness level and your mitochondrial function level you burn between 0.2 0.3 to 0.8 or 9 close to one gram per minute right of fat that doesn't seem quite a quite much but day after day after day after day it counts right but uh during the rest during the rest you burn very little fat right so maybe burning 0.1 0.15 um so why not burning 0.4 0.5 grams uh half a gram for for doing exercise for 60 minutes or 90 minutes right and uh just you get a calculation people can do get a calculator uh you know it just plugs the numbers in and you're going to see that if you have about four days a week uh about five or four to five hours a week um burning fat 0.4 0.5 you know every month you're going to be losing it depends on the time you know and your fat burning but you can be losing one kilo if you want to lose weight right so along with the diet it can really help, you know.

6:46But anyways, that fat max coincides also with zone two. That's a good parameter to see. Thanks so much for listening. To hear the full episode, there's a link in the description.