Big Crash, Finally

This was just about the worst post-exertional sickness I've had since  I started out on this trip in April. I still was under the influence of Benadryl, with some sluggishness and muscular resistance. We went out to Notre Dame and Latin Quarter and I ended up registering 12,000 steps. I've done more than that in this trip and didn't get sick. This time, I stayed in bed all day.

This makes me think that Benadryl has the opposite effect of Sudafed on CFS: it lowers the exercise tolerance. Now, it could well be just coincidence, and there are other factors like jet lag and colder weather here in Paris, or the walk pattern/pace was more taxing. You wouldn't know till you do controlled trial. I could try Benadryl again and experiment, but I don't think I ever will. It has bad effect the next day, period, even if it doesn't lower the exercise tolerance of CFS.

Even if Sudafed and Benadryl have effect on my exercise tolerance, it does not mean that they do on other patients. Even for me, I didn't notice the effect till recently. I've been taking Sudafed since 2009, but only noticed that it partially relieves the ache and fatigue; its effect on the exercise tolerance was not noticed. It could be that my tolerance has increased and became flexible that I'm starting to notice the effect, where as the threshold was a brick wall back then.