Stuart - the best thing I have tried for the fatigue and post exercise malaise is Low Dose Naltrexone (LDN). I am 5 years into my COVID journey and have had my fatigue and malaise lessen a bit so I can now walk about 1/3 of a mile without being winded or tired for the rest of the day but must still pace myself everyday. The LDN gives me an additional small burst of energy about 1 1/2 hours after I take it and it also removes a good share of the inflammation in my body...so less overall pain. My legs are also less weak unless I go completely off my anti-inflammation diet and then they are weak again and painful. Neuropathy is overall better now that I can sleep with less pain.

LDN is started at a "baby" dose for us - about .5 to 1 mg and slowly, slowly worked up to 4.5 mg. For the first two weeks, it made me tired (so I took it at night) and it gave me quite vivid dreams (not nightmares). After two weeks, it gave me insomnia so I now take it in the daytime prior to 2 pm. For me, the 4.5 dose did not work as well as 2.5 so I decreased the dose to where I felt the best. This is typical for many using LDN. Some people even split their dose so they get a burst of energy twice a day.