questions for Dr. San Millan/on metabolism, zone 2 and cancer cachexia
Hello! I have several questions that hopefully can be addressed in the future discussions. 1) Can you please go over in a bit more detail about what happens at each metabolic threshold? Dr. San Millan's page talks about 7 zones, with different preferred fuels in each zone and different (fast or slow) muscle fibers being engaged. How does that relate to VT1, VT2 and VO2max thresholds that I see in the literature? 2) You mentioned before that zone 2 threshold blood lactate starts to increase, and that in professional athletes this occurs at much higher power because their muscles clear lactate faster than it can get into the blood to be measured. What is the difference in lactate concentrations in muscle vs blood - has it/can it be measured? Are there estimates on how quickly these processes occur, i.e., how quickly lactate forms and is cleared from muscle vs blood? 3) If I understand correctly, cancer cachexia is characterized by abnormal nutrient depletion. Can you please talk about what happens metabolically in cachectic patients? Has anyone measured their ventilatory thresholds? Is there benefit of zone 2 training for cancer patients to increase mitochondrial capacity (has anyone tried it) and potentially stave off cachexia? There was a discussion in Dom's AMA about ketogenic diet being a potential approach to delay cachexia - has there been new information on it? Are there any mechanistic explanations for why that could be happening on a metabolic level? And a couple of small things: 1) I tried to follow up on podcast with Sid Mukherjee where he talks about his clinical trial to test the impact of combination of a PI3K inhibitor with ketogenic diet. Have there been any updates on this topic? I found this clinical trial (https://clinicaltrials.gov/ct2/show/NCT04750941), I'm assuming that's the one he was talking about, but I haven't seen any even preliminary follow-up or mention of the study since you talked about it on the podcast. I would love to learn more about any follow-up on connection between hyperinsulinemia and cancer progression, and potential underlying mechanisms of why one might be facilitating progression of the other. 2) A small note - in the Inigo San Milan episode, the link to figure 5 is not leading to the source of the figure and should probably be updated. Thank you , and I am very much looking forward to your podcast!
Recent Podcast on Covid
It was great listening to you and your guests regarding Covid, but the session was at times confusing-for example-if you are fully vaccinated are you advocating not wearing a mask in public or were you all suggesting-it’s all individual opinion.As a healthcare worker in a crazy busy ED where masks are mandated I came away very confused
Zone 2 vs Zone 3 Exercise
Is it true that all intensities below VO2 build Mitochondria, but it is specifically the fat utilization systems that are better trained in Zone 2? From listening to podcasts from people using gas exchange analyzers it sounds like the point at which you use the maximum absolute amount of fat can range from Zone 2 all the way up to Zone 4 making the best point to train fat utilization not Zone 2 but at this point of maximal fat use? Obviously Zone 3 is more tiring than Zone 2 but if recovery is not an issues because you are time limited is Zone 3 not a better option?
Do you believe in the cholesterol hypothesis?
Based on several of your podcasts, it seems you believe in the cholesterol hypothesis, and you recommend statins for some patients. I'd like to know what you think about this article entitled, "LDL-C does not cause cardiovascular disease: a comprehensive review of the current literature," along with their recommendations to stop prescribing cholesterol lowering medications, and instead to start identifying and targeting the actual causes of CVD. Here's the url: https://www.tandfonline.com/doi/full/10.1080/17512433.2018.1519391?src=recsys