ok so im 15 and have no way to access weights. i have a pullup bar, but thats it. so basically all i can do is pullups, chin ups, push ups, sit ups, leg lifts, and anything else that i can do with just my body. would doing a cycle type workout where i do one set of push ups, then one set of sit ups, etc. for like 5 cycles be ok? if so, how long should i rest between each excercise, and can i do that everyday? also, would it be best to do my cardio (running) at a different time of the day, or right before, or after my workout?