Exercising for long periods makes your heart adept at handling a 60-minute jog, but it accomplishes this by trading in its ability to rapidly provide you with big bursts when circumstances might demand.
The real key to prevent heart disease and protect and strengthen your heart is to induce the opposite adaptive response to that produced by continuous cardio and increase your heart’s reserve capacity. Bigger, faster cardiac output more immediately available is what you really need.
From page 8 of PACE®: Rediscover Your Native Fitness
If you look back through the archives of this blog, you'll find a fair bit about interval training. In particular there is a fair bit of research on its efficiency in terms of improving VO2 max (a sort of measure of getting out of breath when you train hard).
CrossFit Endurance is building a whole programme of training for endurance athletes around breif interval based sessions and is worth checking out.
The work that Dr Craig Duncan has done is also interesting with respect to training athletes - e.g. the 20 metre rule.
I've also pointed to Mark Sisson's writing the dangers of excessive "cardio" - Chronic Cardio
Anyway, what about the average person that wants to use intervals to get fitter and burn fat?
Craig Ballantye has some good background in his Turbulence Training material that I've promoted elsewhere.
However, I wanted to point to something that I have linked to on this blog for a long time but not really reviewed, that is Dr Sears PACE book.
I first came across Dr Sears through his book : The Doctor's Heart Cure , which is a well written and accessible look at heart disease. It challenges the conventional wisdom about cholesterol, diet and exercise, recommending a low carb, higher fat diet coupled with interval training.
None of that will be new if you read the sort of things I link to and post here. Sears calls his aproach to intervals PACE:
PACE® stands for Progressively Accelerating Cardiopulmonary Exertion. The PACE® program starts with interval training, but takes it a step further.
He introduces it in the Heart Book, but it is not the focus there - just an element of a programme he is presenting.
The PACE book (and now I understand there is a DVD too) are focussed wholly on this approach.
Some ebooks that I have bought have disapointed me. The advertising copy - which always seems to come in the same style - promises a lot while the product fails to deliver. I can assure you that the PACE book is worth it.
The ebook is 144 pages, dense with information, and explains the science behind interval training for fat loss and fitness.
It also presents a good basic calisthenics routine for strength building. It isn't aimed at athletes, but at the average person who needs to incorporate some rational training and physical activity to their life. It explains why interval training works and how to apply it.
“Cardio” has become so popular we have accepted the term as a synonym for exercise for your heart. This unfortunate misnomer is worse than a waste of your time. It only takes you further from your natural challenges and aggravates the problem. It’s not natural to repeat the same movement continuously 10,000 times over without variation or rest. It will not build heart health and does not correct for what we are lacking.
I enjoyed reading it and learned some new things as well.