Invariably, you’re going to run into a few plans and programs that purport to be really good for you, but in the end, there isn’t really anything that’s to be gained by them. How to tell a good program from one that doesn’t really do much is this: is this program that you’re dealing with going to be able to yield in a way that’s measurable? It’s a lot more complicated than this, but you can think of it in terms of running distances. If the program says (and remember this is just to illustrate the point) that at the end of it you’ll be able to run a 7k, versus the 1 mile you were able to do previous to the program, then that’s a measurable yield, and you can judge these cardio workout plans accordingly. And that’s really the key. See, exercise and fitness, it’s a highly quantitative thing, as is cardiovascular health.