Automated Adaptive Pacing

Imagine a little birdie that can tell you how you are going to feel tomorrow. Then imagine it telling you what/how much you can do on any given day. Better yet, it can even tell you how you going to feel for the next several days, hour by hour, so that you can plan activities for a week out at a time.

In the winter of 2008-2009, in the thick of the sickness, I was in a semi-delirium -- everything around me felt like a dreamscape -- and the gravity felt ten times heavier. It was a struggle to even pick up the phone to lift it to my ear. Then the condition would stabilize briefly bringing some hope for recovery. Next thing, it would tank again leaving me mumbling "why bother?".

One of the complaints by CFS patients is that their conditions are unpredictable. It can worsen for seemingly no reason and it's difficult manage when you can't predict your conditions. All you have is the adaptive pacing strategy that employs a few rules of thumbs and listening to your body to avoid over-exerting and getting sick subsequently.

Listening to your body is fairly subjective, however. In the early stages, I was constantly sick and in no shape to walk. But being cooped up inside the house day after day made me feel crappy and my sleep suffered. So I started walking slowly every other day no matter how I felt. That vastly improved both my mood and sleep. Conversely, when I walked a little faster or more because I felt I could, it almost invariably resulted in post-exertional sickness. Listening to my body has become somewhat useful only recently, and it's mostly about listening for post-exertional fatigue that can lead to post-exertional sickness.

CFS specialists recommend that you do about half you what you think you are able to. This allows enough margin of error so that daily variations and unexpected activities won't bring you down.  But it also leaves half of the precious energy on the table. I've been operating at 10% of my pre-illness level, cutting it by half again doesn't leave much for activities other than taking care of ADL. And doing only 50% won't prevent the post-exertional sickness 100% of the time either, because what you think you are able to do is very imprecise, while the body's reaction to the exertion is precise.

They also recommend that you keep your heart rate below the anaerobic threshold. Going over this threshold presumably puts too much strain on the body and can trigger the post-exertional sickness. But my heart rate has been so variable that keeping it below 95 bps, my anaerobic threshold, has been an impossibility. My heart rate regularly shoot up to 120, at least according to my Fitbit, when I walk even on the days when my resting heart rate is 55.

So I have not had any useful tool to manage to avoid the post-exertional sickness other than keeping the records and maintaining a regular schedule of activities whenever possible. And it has been difficult to string together a week without getting sick. (Though, this has more to do with my lack of discipline than anything else).

That's what this project has been all about, to figure out a useful tool that can assist CFS patients in pacing their activities and avoid getting sick. And it would be useful enough if the tool can help bring up the activity level to 70 or 80% of threshold. That extra 20-30%p, combined with avoiding the sickness, can make a huge difference in quality of living.

So I got an activity tracker last year and start looking to figure out a way to manage my activities at optimal level. There has been some insightful discoveries. After looking at it for almost a year, however, I'm slowly coming to a conclusion that off-the-shelf trackers may not be accurate enough to be useful for CFS patients. We may need a medical grade monitor with higher resolution and precision. That is especially true for severely ill patients who can end up with post-exertional sickness just by walking from the bedroom to the bathroom. I'll also need something that can discern different ADLs with enough precision. But there are still a few more hypotheses (dozens, actually) that I'd like to test before moving on to Android Wear and beyond.

Unfortunately (or fortunately, I shoud say), it appears that my CFS is suddenly improving and perhaps even recovering. I have accumulated one year's worth data, so I may be able to continue with my analysis for a while. But I won't be able to test the predictions on myself anymore. If any CFS patient out there is willing to participate, I'd be happy to work with you. I may be able to help you with managing activities in the process. A second pair of eyes is always useful when you are trying to pace.