UPDATE, July 2021: the 'cure' never quite got me to my normal self, and I relapsed in early March 2021, quite severely by April. I think I was too aggressive in attempting to resume my normal training, though by my usual standards it was pretty wimpy. See my July 2021 update.
As far as I can tell, I have self-cured myself of long-haul COVID*. Just before Thanksgiving, I experienced a huge increase in energy level, and a plummeting of sleep requirements from 12+ hours per day to 8-10 hours per day. I have gotten far stronger on the bike (when I could barely manage an easy 1-mile walk most of October and November!), regaining some of my fitness as well. By “far stronger”, that is comparing a zero to fully functional; I did not ride at all for a full month.
As time allows, I will spell out what I think led to my recovery—a multi-part strategy based on sleep and rest, nutritional support, dietary choices. And now, infrared irradiation, which so far has correlated with stunning improvements (big jumps in wattage) on my now resumed) cycling activities excepting 3 days of rain, but I am eager to ride again when it clears.
Through most of August/September/October/November, I was so weak that a 1-mile walk made me weak. That followed similar but more erratic issues in June and July. Some days I had to go to bed as early as 5PM, then sleep 12-14 hours. Once I slept 16 hours, then was bedridden the following day, too weak to do much more than eat and bathroom. It took a full week to recover from that 'hit'.
I did not consult any doctors (other than some blood tests in late August), since few have even a basic knowledge of nutrition, which is a prerequisite for any organism to be healthy. Indeed, the primary concern of my internist in response to my blood tests was my cholesterol level, when I had been suffering severe brain fog and energy problems for months. There is evidence that cholesterol rises when the body is under duress, particularly infection. Bringing up an inappropriate topic at the wrong time based on a thoroughly discredited cholesterol hypothesis is IMO a horribly inappropriate medical practice.
Below, my workout metrics show the comeback I made beginning November 26. It was November 24th that I noticed a sudden resolving of some symptoms. Over the ensuing ~2 weeks, pulmonary issues steadily resolved, and I made huge gains in power (watts) on the bike with a reduced heart rate for the same power output. On December 10th, I not only hit 212 watts at a reasonable hart rate (for being detrained), I had no sense of systemic fatigue, a problem which had plagued me for months.
As of December 13: brain fog and cognitive issues gone, physical performance is back to normal levels (taking into account 6 months of detraining), cognitive function is excellent, and sleep requirements are reduced back to a normal 8-9 hours, down from 12-14 hours or even 16 hours.
Lingering issues: I can still fatigue more easily, I still have pain in hands and feet occassionally (perhaps due to Hashimoto’s Thyroiditis).