Unless you have ironclad guts, there’s a good chance you’ve thrown up thanks to running. Because upchucking is an unpleasant occurrence that doesn’t discriminate, knowing its possible causes is essential if you want to avoid regurgitating after (or during) a tough run. If you have ever found yourself draped over a wall after picking up your race medal, here are some possible reasons for your gut’s dissatisfaction - and the ways you can try to combat it.