Here again, I like to keep things very simple. Cardio is all about getting your heart rate up (high enough) for a sustained period of time. The first thing you will notice is that you get breathless as the heart and skeletal muscles beg for oxygen. (Okay, this was for people who never tried exercising before). There are many ways to get a good Cardio workout. Check with your doctor before you start any kind of strenuous exercise if you have been physically inactive. I'm not here to prescribe what type of Cardio you should do or how often and for what duration or with what intensity. That's for you to determine. Rule of thumb: always start off gently and build up your stamina gradually. I know that for myself I need to get in 2 - 3 days of Cardio a week to feel at my optimum. There are different types of Cardio I enjoy:
Cycling uphill for twenty minutes. I pick a 10% grade and go for it. After I had my bike stolen for the third time, I've given up cycling for the time being.
Climbing steep mountains. Baldwin Hills works for me. I also get an awesome leg workout every time I climb those stairs.
Stair-Climber in the gym. I used to do that a few years ago. I started with 5 minutes and slowly worked my way up to 45 minutes. I also used to climb 12 flights of stairs three times, back in the day. Great way to rev up that metabolism!
Treadmill. Good all around Cardio, except I don't like the jarring on my knees when I jog.
Dancing. Put me on a dance floor and I can sweat away five pounds in one night. I was a go-go dancer for a DJ at one time.
Sprints. It was my all-time favorite, until I tore a hamstring running at the beach. Ten x 50 yard sprints spaced 120 seconds apart is all I need to work my lower abs, legs and Cardio. Notice how sprinters have tight, thin waists!
Full Body Circuit Training. This one is on top of my list. I'll do three circuits, resting 90 seconds after each circuit, no rest in between exercises, and do eight exercises. Then, I concentrate on a body part and blast it for an hour.
Aerobics Classes. I have taught Aerobics professionally back in the 80's for corporations and gyms. I would teach 45 minute classes 3 times a day. It's too much coordination for me at this point, so I am not too keen.
Rope Jumping. I tried it and I get tangled up. I envy those who can skip like boxers.
Squat/Dumbell-Pullover Super-Setting. I pick a weight I can squat for 20 reps, and a dumbbell I can pull over 12 times, and do 4 Super Sets with 90 seconds rest in between Super Sets. It works wonders.
Walking. Although not as intense, an uphill walk can still build a good sweat if I speed it up.
I know there are other ways like jumping jacks or burpees in combination with mountain-climbers and push-ups etc. Those are just as valid, but not for me. HIIT - High Intensity Training, I've never tried it but I hear it works.