When it comes down to it, modern day version of cardio is most of the time is pure crap. When it comes to fat burning it rarely if ever really does anything that is worth its time. Cardio to most people is spending 30 minutes or more on a treadmill at a moderate pace that is either walking or jogging. Sure you burn a few calories but you also lose muscle mass and store more fat than you want to believe. To truly take off fat like you would take off a t-shirt, you have to be very intense and short.
When you're jogging at a moderate pace your heart rate goes up a little but stays there for as long as possible in the long time to keep it there. That's great for endurance training but you're getting one shred of realistic muscle from doing this. Having a good glimpse of lean muscle mass goes a long way to increase your metabolism, athletic stamina and filling your lungs with powerful oxygen. When I say muscle mass i'm not talking bulky and grotesque looking like a bodybuilder but more of a classic muscular man pre-1970's. Cardio is good for a few reasons but to truly build insane lung power you need to up the ante.
Extreme cardio is purely blowing up your heart rate to a level where you're huffing and puffing in a matter of seconds instead of minutes that's where fat burning comes into play because your oxygen levels need more blood to pump through the heart and other vessels of the central nervous system. When you do short bursts you're installing those hormones that burn calories like a flame to gasoline. That's why I love developing my style of the Superhero Sprints Program. It's purpose is to keep your workouts short and sweet to where you're basically resting more than working and the reason is because every fiber in your body is taken to optimum levels. Workouts at a great clip are no more than 20-25 minutes, when you add a finisher no more than 35 minutes total of high intensity interval training. When you train cardio for 60 minutes or more at a moderate pace your strength and muscle diminish but you still have your stamina yet build up a level of flab. When you train crazy hard on Superhero Style Training, you're decreasing fat, improving both strength & stamina and you pack on natural and lean muscle.
This style of training is no more than 3x a week because of the need of the muscles and tendons to recover from an insane session. It has been proven from experiments around the country and parts of Europe where HIT is the best way to improve muscle and burn off fat the fastest way possible. I have been studying and testing things out for over 18 years (everyday in the last 10+) and I have no other method to increase growth hormone and metabolic conditioning than HIT Style fitness. That's why I enjoy the workouts I do because I get to eat what I can to fuel up and i'm still burning calories hours after the workout barely doing anything. The basics of Superhero Fitness is doing 5 Sprints (8 if you're outdoors), a circuit & (if you're willing to go even further) a finisher that's roughly no more than 10 minutes. Take a look at the program and see what I mean, there's all kinds of exercises to choose from both weighted and bodyweight, a beginners program, indoor and outdoor training plus training on Supersets. This truly is one of the best courses I've ever come across.
This isn't some rinky-dink training where you go very slow and do little jogs, this is high levels of training that is meant to increase your fitness and building a realistic muscular/lean physique with the purpose of being able to eat enough to fuel up, drink plenty of water and taking a rest day and that could be a walk in the park, hike, swimming whatever you want to stay active but to a level of degree.