you can run pre workouts on cycle, you just need to be careful... you technically are not supposed to use stimulants on cycle because they can raise your blood pressure, but some people they do not effect... you just need to stop using it if you start to feel weird or if your blood pressure gets too high... i used pre workouts on my helladrol cycle and at the very beginning they made me feel a little weird but I was fine after that... just be smart and know your body... everyone reacts differently...