Every time I go for a run I get sick afterwards. I vomit and see spots. This doesn’t happen when I do other exercises or even activities that require short bursts of running (ie. football, racquetball). I also am sure to hydrate throughout the day before I run. I actually am almost always fairly well hydrated. It has gotten to the point where a light run for only about 7 minutes has me collapsed and vomiting on my bathroom floor.