There is a big difference between using illness as an explanation, and using it as an excuse. I’d like to illustrate this by using my recent diagnoses of Anemia and Exercise-Induced Asthma.
Several people in my life have interpreted the asthma diagnosis as “you shouldn’t exert yourself!” but at no point have I turned down an outing despite anticipating shortness of breath, pain in my lungs, intense coughing/retching, and occasional injury as I stumbled due lacking the red blood cells necessary to transport oxygen even if I could breathe it in. In fact, the judgmental people who assumed I needed to exercise and lay off the cigarettes (I don’t smoke) were often worse than the symptoms themselves. Although to be fair, I hoped I merely needed to exercise more, too.
Instead I’d pack up my gear and rush out the door with as much anticipation for the adventure ahead as I would if I didn’t end up suffering. I am a nature photographer, and running around outdoors with a heavy backpack is a prerequisite. Although my pace was affected, and I learned the hard way to turn down hiking-based tours and group outings with strangers, my overall determination was not.
Many hikes have been unintentional. An stroll at ground level saw me follow a sign stating “Challenge yourself! Get there faster” up a terrifying trail. Ill-prepared, gasping for breath, and unable to plod more than a few paces at a time, I wondered where I was trying to go in the first place… and nearly turned around. Doing so would have been a mistake, as the trail led me straight to a bird that had eluded my camera for 2 years. On an easier trail I would have missed it entirely.
I am not discounting the constraints that mental and physical illness oftentimes inflict, but at some point mind over matter needs to factor in. A slow climb up that hill is better than no climb at all. It’s a big world, and you won’t experience it sitting on your ass.