I’ve noticed that for me exercise works as a canary of a coal mine for the body. When the body is getting overstressed, it is first noticeable during exercise.
Things like flu, small aches and stiffness in the body are normal in human life. Urban life and stationary jobs strain the body. Usually these smaller things pass on their own and you don’t pay too much attention on them. But sometimes those are a signal of something bigger. A disease that needs treatment or overstress that you should react to.
For me exercise works great on separating the signals that are meaningful and need to be reacted to. Exercise stresses the body in different way than home and work life. I do CrossFit exercise twice a week and have been doing for three years. If for many workouts in succession I don’t feel normal, it is usually a sign that it is not the normal everyday things going on. I notice it from being out of breath easily and muscle pain after workouts being greater and taking longer to pass.
I also follow my workout results (using our own workout journal app WODconnect). My memory for results is horrible so having a place for the results that makes them comparable over time is very valuable. Sometimes not being able to get the results I have been previously been capable of is also a sign of something more severe (sometimes it is just being tired from previous workouts or something else).
Listening to your body is never stupid but it is especially important when exercising.