i run at least 2 miles a day. as long as you dont get high before you do it you are fine. really it i love doing it because now i also never ever get that burnt out lazy feeling i got with doing nothing while smoking. whereas if i smoke a pack of cigarettes the day before(i dont smoke cigs daily) i really really feel it in my lungs and am wheezing by the end. i dont buy weed as often as i used to now but when i do buy it i smoke at least once a day. i find it is a nice way to relax after you work out