Is it necessary to do cardio while you are taking a 4 week cycle of Clen? I plan to put in a solid hour to an hour and a half of lifting a day and eating about 2500 of good calories and about 270 grams of protein. I am also considering taking Cytomel in between Clen cycles. I am just afraid my heart pounding out of my chest while doing the cardio. Any input anyone has would be greatly appreciated. Thanks.