Marco lovely for you to share the data becuase I was looking for a reference and this gives me a lot! I am in a low carb diet myself at the moment on Day 12 with the intention of losing some visceral fat (I am very healthy and fit just have stubborn waist area fat). I observed very similar results as yourself. I had my HRV shoot up(87 from baseline of 65) in the initial days which was accompanied by great mental sharpness. From Day 8 the HRV dropped to 45 and has remained there since. I have lost the sharpness and my body does feel under stress which reflects in the HRV. I am wondering if this is a temporary phase or do I introduce carbs? How did you navigate this and what was your take on this?
thanks Sangram! In my experience it lasted a few weeks, then back to normal (I have now been eating very periodized - which means lower carb about 5 days per week - for about 4 months, with stable data, energy levels and weight / body composition)
those initial weeks/months with caloric deficit and changes in macronutrients were in general quite fatigue-inducing, hence I trained daily (as that's part of my life/routine) but without big volumes, more shorter runs with a little quality here in there (strides, etc.), and a proper workout per week when having more carbs. In general, I think those phases (especially the caloric deficit, but also a large change in macronutrients) are not good moments to train well and make gains, and we need to adjust a bit based on how we feel (I'd say regardless of HRV!). I think those are not good times to 'power through' as we are well aware we are already stressing the body and waiting for it to adjust or for us to stop the caloric deficit, which is something that can only last for a certain period of time.
HRV can be a useful indicator but I'd be cautious even with a stable HRV. Makes sense?
Thanks as usual for your insight here. You seem to be one of the few people consistently writing on HRV & health, especially unusually high HRV. I end up directed back to your blog time and time again in my searches. I use HRV4Tracker in the mornings as well as Stress Monitor which tracks rMSSD via Apple Watch throughout the day, as I am trying to find correlations for managing my health conditions.
I’m curious if, purely theoretically, you’d have any ideas on what might drive very high HRV at the end of an intermittent fast. I’ve been fasting 16-18 hours overnight for probably a decade. As I have been monitoring my hour to hour HRV I have noticed that my HRV will often spike to over 200 (E.G. rMSSD 242, HR 56 which is typical RHR for me) coinciding with hunger at the end of my fast. After eating it will drop, either down to normal or worse than normal depending on other factors. I am doing my own experiments to reduce this swing, but I’m extremely curious whether you have any ideas about the underlying mechanics generally speaking (no medical advice :) )
regarding the data, my recommendation would be to double check with an ECG (like a Polar chest strap paired with an app like the HRV Logger), as unfortunately continuous tracking is highly problematic per se, and this problem is much worse with optical sensing, see some notes here: https://marcoaltini.substack.com/p/a-quick-note-on-continuous-heart - my take would be that the data is very noisy, but again, the only way to make sure it's an actual physiological change, is probably to measure with a different setup. Have a nice weekend
As a regular user can we get the option of normalised HRV? Even if it's a one off addon charge? I'm battling some IBS issues & on days I can't fuel properly I'm in a cal deficit & my measurements aren't that useful cause it's reporting much higher. My resting drops up to 10 bpm when I'm in a deficit!
Marco lovely for you to share the data becuase I was looking for a reference and this gives me a lot! I am in a low carb diet myself at the moment on Day 12 with the intention of losing some visceral fat (I am very healthy and fit just have stubborn waist area fat). I observed very similar results as yourself. I had my HRV shoot up(87 from baseline of 65) in the initial days which was accompanied by great mental sharpness. From Day 8 the HRV dropped to 45 and has remained there since. I have lost the sharpness and my body does feel under stress which reflects in the HRV. I am wondering if this is a temporary phase or do I introduce carbs? How did you navigate this and what was your take on this?
thanks Sangram! In my experience it lasted a few weeks, then back to normal (I have now been eating very periodized - which means lower carb about 5 days per week - for about 4 months, with stable data, energy levels and weight / body composition)
Thanks for sharing and that is good to know! Did you lower your training load when the HRV was low because of the body in some kind of stress?
those initial weeks/months with caloric deficit and changes in macronutrients were in general quite fatigue-inducing, hence I trained daily (as that's part of my life/routine) but without big volumes, more shorter runs with a little quality here in there (strides, etc.), and a proper workout per week when having more carbs. In general, I think those phases (especially the caloric deficit, but also a large change in macronutrients) are not good moments to train well and make gains, and we need to adjust a bit based on how we feel (I'd say regardless of HRV!). I think those are not good times to 'power through' as we are well aware we are already stressing the body and waiting for it to adjust or for us to stop the caloric deficit, which is something that can only last for a certain period of time.
HRV can be a useful indicator but I'd be cautious even with a stable HRV. Makes sense?
That makes total sense. Appreciate sharing your experience.
no worries. You can find some more info here, as I wrote this one later on: https://marcoaltini.substack.com/p/periodized-nutrition-for-endurance
Thanks as usual for your insight here. You seem to be one of the few people consistently writing on HRV & health, especially unusually high HRV. I end up directed back to your blog time and time again in my searches. I use HRV4Tracker in the mornings as well as Stress Monitor which tracks rMSSD via Apple Watch throughout the day, as I am trying to find correlations for managing my health conditions.
I’m curious if, purely theoretically, you’d have any ideas on what might drive very high HRV at the end of an intermittent fast. I’ve been fasting 16-18 hours overnight for probably a decade. As I have been monitoring my hour to hour HRV I have noticed that my HRV will often spike to over 200 (E.G. rMSSD 242, HR 56 which is typical RHR for me) coinciding with hunger at the end of my fast. After eating it will drop, either down to normal or worse than normal depending on other factors. I am doing my own experiments to reduce this swing, but I’m extremely curious whether you have any ideas about the underlying mechanics generally speaking (no medical advice :) )
thank you Michelle, I appreciate the kind words.
regarding the data, my recommendation would be to double check with an ECG (like a Polar chest strap paired with an app like the HRV Logger), as unfortunately continuous tracking is highly problematic per se, and this problem is much worse with optical sensing, see some notes here: https://marcoaltini.substack.com/p/a-quick-note-on-continuous-heart - my take would be that the data is very noisy, but again, the only way to make sure it's an actual physiological change, is probably to measure with a different setup. Have a nice weekend
Interesting thoughts Marco.
As a regular user can we get the option of normalised HRV? Even if it's a one off addon charge? I'm battling some IBS issues & on days I can't fuel properly I'm in a cal deficit & my measurements aren't that useful cause it's reporting much higher. My resting drops up to 10 bpm when I'm in a deficit!
thank you Dush, that seems consistent indeed with my experience.
Normalized HRV is part of Pro, not the regular app. You can try it here: https://hrv4training.web.app