Not sure exactly what my question is, I think it's a few things, hopefully you all can help me whittle it down! My phone measures my step count so I have a good amount of data about how many steps I can walk on average a day / week / month / year etc. I know there's often discussion on here about what things can be / are measured in clinicals trials etc for ME. I'm wondering what things can be measured that people feel are potentially relevant to ME, and if they can be measured by the patient, at home, what devices would be needed? For example, I had a smart watch for a while that measured my heart rate, and that seemed like useful info, there definitely seemed to be a very clear correlation between my heart rate going above a certain point and me feeling absolutely terrible afterwards. I since sold the smart watch as I wasn't sure what else to do with the data. But I'm curious about what other things can be measured by ourselves, and if they might be relevant to ME, and why. I know it's fairly inexpensive to buy something for taking one's own blood pressure, wondering if there is something with a more intentional medical application than a smart watch for heart rate, I think it's possible to measure blood sugar levels at home, but I'm not sure if that's useful relevant etc. So yea - what do people measure themselves, how and why?
I don't measure anything, but I have in the past measured HR and HRV using a Polar chest strap and apps. In general, a chest strap gives more accurate readings than watches. There's a lot of material on the forum (and elsewhere online) about HRV — though I feel it is often overhyped. One thing that can be measured easily is device screentime, which correlates well with mental/cognitive exertion if one uses their phone and/or laptop regularly. My screentime will correlate with how well I'm feeling, but the latter drives the former and not vice-versa, so it may not be that useful to track.
Someone once gave me a glucose / ketone monitor, but it was quite old and seemed like way too much faff to be worthwhile. The newer devices are much easier and might be worthwhile if you felt like diet and metabolism was an issue.
I tend to hover around 92 for blood oxygen, and have wondered if one of those finger-clippy laser gubbins would be a fun accessory, but I have no real reason to think that the data would make any difference. They must be super-cheap, though, as home medical toys go.
I have a finger pulse oximeter which I use occasionally when I don't believe my fitbit's pulse rate recording. Useful as a cross check. My oxygen level on that ranges from 95 to 98, ie normal range. I bought it in the early days of Covid-19 when the news came out that it was worth monitoring oxygen levels when you catch Covid to see whether it's dropped low enough to need to go to hospital to be given oxygen. I find my fitbit worn on my wrist is accurate enough on steps and heart rate for guiding me on what level of activity I can manage without triggering PEM. Of course it counts arm movements as well as steps, but since I find things like dressing and folding laundry exhausting, that's actually useful for me. The heart rate is useful as a reminder to stop activities sooner than I was doing - I tend to keep pushing on once up and doing stuff, rather than taking rests if I don't have something more objective to remind me to take a break. The combination of both keeping my step count and heart rate below levels I find work for me has helped reduce frequency and severity of PEM. Also the pattern of daily resting heart rate reflects fairly accurately my state of health. I haven't looked into heart rate variability. I have been using these for several years now, and look at them less often as I've adjusted my activity levels and patterns and live a fairly regular very low key life most of the time. I can tell by my symptoms when I need to stop activity usually, though heart rate is a cross-check. I'm fortunate that cognitive activity seems less of a problem for me in that I can spend far more time each day on it than on physical activity without triggering severe PEM. Though I do wonder whether cutting back significantly on cognitive activity might allow me to do more physically and help me to feel less exhausted and sick all the time. How do you measure screen time? Is there an app?
The entertainment value wears off quite soon, to be honest, although they do provide a quick way to measure your heart rate if you haven't got a smart watch. My blood oxygen is consistently around this rate too, unless I've only just stopped doing something, in which case it's often in the high 90s. This suggests the low readings are due to reduced peripheral circulation when resting. I haven't got gangrenous hands, so it probably just tells me I sit down a lot. They are, we were advised to get one for my late mum after an operation. I think it was £15 at 2017 prices. I ended up with it for some reason, but then again I ended up with most of the stuff she didn't want—say what you like about my mum, but she was a champion offloader of gadgets and tat.
Devices usually measure this by default, and you can check it in settings. Or you can download third-party apps.
If you have Mac systems, you have to expend quite a lot of energy persuading the bloody things NOT to nag you about your screen time. It drives me nuts—see also Focus, which is where they turn off your alerts when you're working or sleeping. Which might be okay when they tell you about it, but not so much when they don't. People have overslept or missed really important calls, for no other reason than that their flaming OS had updated with some new variant of digital martial law automatically activated. But grumbles aside, I'm sure it's very easy to do this if you do a Google query about whatever OS you use.