Not that long ago when I felt like I have the last few days, I would have used it as an excuse to not work out. I had muscle induced headaches. Like pretty bad, but with ibuprofen, the muscle achiness went away and so did the headache.
Now, I knew better than to do the exercises that strained my neck in the first place (strength training), but instead of sitting on my duff, I did week 1 day 2 of C25k and my total miles was 2.27 in 30 minutes and with 10 minutes of walking (I walk fast on both my warm up and cool down as I'm a fast walker) and then another 8 minutes of running and 12 minutes of walking, that's not a bad pace at all. that is 13:22 minute miles with almost 75 percent of it walking! I walk about 14:45 - 15 minute miles with straight walking, so the running part definitely speeds me up. And best of all, it felt great - not killing me.
Then, I came in, cooled down and then got my bike ready to take out. Last year I bought a Burley Travoy trailer for my bike so I could go bike riding to the store instead of driving. We have bike/walking paths from door to door of the 2 miles or so. I rode there, got my shopping done and came home - adding even more fitness to my day by getting a needed chore done. I'm going to do that several times a week and the same when I go to the farmer's market starting in June.
Anyway.... I did all that when in the past I would have used feeling bad as an excuse to do nothing. And guess what? I feel GREAT! And strong! And very proud of myself! Yay me!