If you follow the current fitness trends you know by now that high intensity interval training is becoming incredibly popular throughout the entire world. I personally do a lot of this myself and have experimented with it intensively, so today I would like to share my opinions on it and why I believe it's becoming so popular.
The first reason it's becoming popular is simply because it saves time. You can burn as many calories in a 20 minute workout as you can jogging for 50-60 minutes, so who would not want to do that? Everyone today wants to save time and doing this type of training is a great way to do that.
The second reason is simply because it's a lot less boring than low intensity training. A lot of people need more excitement in their lives and high intensity interval training is a great way to do that. I personally do not do a lot of low intensity training simply for the fact that to me, it's incredibly boring. I think a lot of people feel the same way!
The third reason is because unlike low intensity training, high intensity training helps preserve muscle mass while helping you lose weight at the same time. It releases a much higher percentage of muscle-building hormones such as testosterone and human growth hormone and doing exercises such as sprints actually increases the strength in your legs without doing any "strength-building" exercises!
The fourth reason it is becoming popular is because of something called Excess post-exercise oxygen consumption (EPOC). Simply put, after doing high intensity interval training your body burns more calories over the next 24 hours or so. Comparing that, low intensity really only boosts your calorie burning rate while you're actually doing the exercises.
The final reason it's becoming more popular is because there seems to be a general movement towards more athletic training, which a lot of times includes very high intensity exercises. You see things now such as Caveman training, MMA training, and Cross-fit that is starting to become very popular around the world – and by doing those programs you're pretty much automatically required to do high intensity training!
Although high intensity interval training is not for everyone, I think the general movement in fitness for 2009 and all years after this is that more people will start doing more athletic based exercises which are more fun, usually work better, and take less time than lower intensity training.