These substances are metabolized by the liver. Stimulants elevate the mood, depressants slower down the activity of the brain, and body. Once they are taken inside the body, they reach the specific target organs, act at the site, and the debris is metabolized by the liver and thrown out.
Jump up into the air as high as you can. Land softly and immediately lower into the next rep.
Do as many reps as possible in 45 seconds.
I think one thing you could do in order to measure your cardiovascular strength you can do a full sprint run. In order to help improve your fitness levels you can swim, jog/run, body weight exercises, and a balanced diet.