So, what can you do to make sure that you're not barfing during your next spin class? Well, staying hydrated is one great way to keep blood flowing in the right places, prevent heat illnesses, and help recover after a tough workout . But if you start to feel nauseous and you're already in the midst of a workout, then it's a good idea to dial back your intensity, and take a break until you feel better — which can take hours if you're waiting for your core body temperature to come down. Definitely resist the urge to push through the nausea, because that will only make you feel worse. Feeling nauseous during exercise is normal regardless of your fitness level, so it's not a sign that you're out of shape either.