I like to give credit where credit is due, so I will fully link to an amazing blog written by Tony Gentilcore - But what do you do for cardio?
The best way to summarize the blog:
I highly recommend you head over and check out Tony's post because it is a great, quick read! It also summarizes what I have been thinking about over the past year - year and a half, but have finally gotten my thoughts together to articulate what I wanted to say.
I get questions from people ALL the time, especially when it comes to doing a program like P90X - what about the cardio? Don't even get me started on the people who are coming off of doing a program like Insanity...I think these folks think that their hearts are going to shrivel up and die because they don't have their beloved jumping up and down at a million miles an hour.
Let me state this one thing loud and clear. If you are looking for a challenge, a way to improve your cardio conditioning, a way to lose weight, etc. Insanity is pretty hard to beat. It is a great (albeit, HARD) home workout program. It really does test you physically. However, don't for a second think that it is the only way to get "fit," nor is it right for everyone.
One of my most popular blogs of all time is: "Should I do Insanity if I'm a skinny guy and can't keep my weight up?"
Keep in mind that cardiovascular exercise is determined to be doing something that elevates your heart rate to a level above resting for a certain period of time. You do NOT need to get your heart rate to pound through the roof in order to lose weight. In fact, unless you are specifically training for a specific cardiovascular-specific event (5k, marathon, hockey, soccer, etc.) then lifting some heavy things, and getting your heart rate up a bit will work just fine to keep you healthy and at a reasonable weight.
Want more proof? Over the past year and a half, I feel as though I have drastically cut back on how much "cardio" I do. I have grown up playing soccer and hockey, and have enjoyed training for Tough Mudders and the World's Toughest Mudder, and I was definitely in great shape, but it didn't really change the way I look all that much, nor did it need to be done to make me "healthier."
So, since I have cut out a lot of my "traditional cardio," I have substituted in more heavy lifting, compound lifting, all in attempt to work towards new goals - gaining weight and muscle. I think I have changed a lot during this time and still feel great!
Another misconception that I come across all the time is; I need "cardio" to lose weight. Not true at all. Remember that exercise is great for your body, and it can help you lose weight, but weight is largely controlled by what you consume. If you want to gain weight - eat a lot. If you want to lose weight - eat less....
At the end of the day, what I'm saying is, don't be so attached to the idea of "traditional cardiovascular exercise." As Tony Gentilcore mentions in his post, just try and do 20 heavy squats without getting your heart rate up.