Personally I have never used these two together. However I have a buddy who has done it 3 times now. Right now he is running Test Tren and Clen. He has the normal sides sweats shakes insomnia. I would just make sure your taking your clen very early in the day and also watch carb intake after 4 or so in the afternoon. Yes Clenbuterol can make cardio harder than normal to do in duration. I usually try to spread out my clen and cardio as far apart as possible. I also have got up early done my cardio then took my clen. Just try a few things everyone reacts in a different way. Good luck bro.