Evidence for prolonged fasting in managing insulin resistance in T2D/obese individuals?
Is a prolonged fast (3-7+ days) still something you would recommend for improving insulin resistance and other symptoms of T2D in older, obese individuals? The conversation with Dr. Jason Fung years ago made the case strongly, but I've seen so much controversy around Fung lately that I'm not sure how to interpret it. Any thoughts on up to date evidence and suggestions? Thanks!
Rucking Conversions for Fitness Apps
Followed Peter's lead and started rucking a couple of months ago. I usually hit the gym for resistance training 4-5X /week around 4:45 a.m., and try to follow with a ruck on three of those days. I am pretty entrenched in the Apple ecosystem, which includes the watch. When I ruck I use the program labeled "Other", just so I know it wasn't a hike or walk. I noticed right away that the fitness app does not make any adjustments for the amount of load I have in my rucksack. Is there a conversion or modification I can utilize to get a better statistical measurement of my work?
VO2 Max / Cardio Fitness on the Apple Watch
One of the features on the Apple Watch is the ability to estimate VO2 Max. Based on VO2 Max, age and gender, Apple also gives you a Cardio Fitness level - Low, Below Average, Above Average and High. This is done for each decade of age (20 - 29, 30 - 39, etc.). Apple has published a document entitled “Using Apple Watch to Estimate Cardio Fitness with VO2 max” which explains the research that was done to develop the algorithm for estimating VO2 Max. You can view or download this document from: https://www.apple.com/healthcare/docs/site/Using_Apple_Watch_to_Estimate_Cardio_Fitness_with_VO2_max.pdf I have heard you talk about VO2 Max on many podcasts - both on The Drive and on other podcasts where you were a guest. You clearly state that this is the most important metric that one can improve in order to significantly increase their health span and life span. I’ve never heard you talk about the fact that VO2 Max can be easily estimated by anyone who wears an Apple Watch. I know that you are trying to increase the awareness of the importance of VO2 Max, and given the popularity of the Apple Watch, I think that if you educate people about the Cardio Fitness / VO2 Max on the Apple Watch, it would really help to spread the word. That being said, I don’t know what your take is on the accuracy of the Apple Watch algorithm for estimating (guesstimating) the VO2 Max, or if you’re even familiar with it. Here are two YouTube videos where the VO2 Max on the Apple Watch and other watches was compared to a lab based VO2 Max test: https://www.youtube.com/watch?v=30QUCjh_Q80 https://www.youtube.com/watch?v=MzMZ6ynDxE4 Both of these videos conclude that the Apple Watch (and Garmin) do a “pretty good” job of estimating VO2 Max. Since I’m sure you understand this better than me, you’re probably able to judge this better than I am after watching these videos. Personally, since I haven’t seen any official test of the accuracy of VO2 Max on the Apple Watch, I don’t count on it being totally accurate. However, I do feel that it provides a good estimate, and more importantly that it will provide a good picture of whether one’s VO2 Max is going up, down or staying steady. I believe that this can be very helpful. Many Apple Watch users don’t even know about the VO2 Max / Cardio Fitness feature, but in many cases we can see their VO2 Max history from a year or two in the past, and that gives a very good picture of what has been happening over that time. The estimated VO2 max is calculated each time someone does an Outdoor Walk or Outdoor Run workout that is recorded on the Apple Watch. As a result - many people are having their VO2 Max / Cardio Fitness Level recorded, but they don’t even know that it was recorded and that the history is stored on the iPhone in the Health app. I often help people look at their Cardio Fitness together with their Activity Charts for the same time period. The Activity Charts includes Move (Active Calories burned), Exercise (number of minutes a day), and Stand (number of hours where they stood up at least once for a minute). The Stand hours are not as important as the Active Calories and Exercise. These are the famous “Activity Rings” on the Apple Watch. By looking at their Cardio Fitness / VO2 Max and their Activity Charts over the past year or two, we can get a good picture of their fitness level and what they have done that caused it to increase or decrease. Given the importance that you give to VO2 Max, I think it is important for you to talk about how the Apple Watch can help people check and monitor their VO2 Max over time. I don’t know if this would be appropriate for an AMA or perhaps a regular podcast on The Drive. If you’re not that familiar with the Apple Watch, I’d be happy to help you with this, and help you figure out if this is something that you’d want to learn more about so that you can help more people use their Apple Watch in order to improve their VO2 Max. As I mentioned earlier, Apple classifies Cardio Fitness into quartiles based on the VO2 Max where: Low Level is below 25%, Below Average Level is 25 - 49% Above Average Level is 50 - 74% High Level is above 75% I’m 66 years old. According to my Apple Watch, my VO2 Max has varied between 41.5 - 43.5 over the past year. The Apple Watch considers this a High Level of Cardio Fitness for a Male over 60. For a male 60+, high is considered a VO2 Max > 36 For a male 50 - 59 high is considered a VO2 Max > 41 So my Cardio Fitness is considered high for a Male 50 - 59. This means that I’m close to having a high Cardio Fitness Level for someone who is 20 years younger. I know that this is what you think people should strive for.