Test Prop wont get you ripped overnight or make cardio suddenly magical or easy. I'm using 125mg Prop EOD right now and I can say I love this stuff! Great compound and my favorite form of test by far. If your goal is fat loss the Prop will make you retain most of your muscle while you cut down. It wont produce the results of Tren but it also wont give you the terrible side effects that Tren gave me. We all react differently and my body doesnt agree with Tren. Prop will give you a boost in endurance which will help with your cardio workouts. So I guess you could argue that Prop will help with cardio. But basically, YES, you should do cardio if your goal is fat loss during your cycle using Prop. You will feel a difference after approximately 3 injections and then see a difference in the mirror in approximately 10-21 days of being on Prop. I could see a difference after 2 weeks and Im now headed into week 4 and can see a really big difference. Great, great, great compound. Gotta love Prop.