Is High Intensity Exercise Dangerous?

High intensity exercise like HIIT and Tabata is becoming ever more popular, as it looks like a time-effective method to get fit. But is it safe?

Izumi Tabata

Already in 1996 Japanese researcher Izumi Tabata found that short, high to very high intensity exercise bouts with 10 seconds rest between them were more effective than moderate-intensity exercise. But for almost a decade his style of training was only used by the occasional professional athlete.

This changed when in 2005 another study came along. One that arrived at basically the same findings, yet sold the whole concept from a much sexier angle: if you want to get fit but lack time, do intervals. In a world where everybody has so little time, getting fit on overdrive is a strong selling point.

Accordingly, you today have Time magazine running articles for those who “want to get in shape but just don’t have the time,” and Men’s Health gushing over an “unbelievable 4-Minute cardio workout.”

And yes, it may very well work, but we should look at the safety bit just a tad more intensely than those fitness sites, magazines and the rest. For a “tad” we actually don’t have to go that far, because they usually don’t say a word about that aspect of HIIT and Tabata.

Slightly Surprising – Or Not

Case in point, and a rather ironic example of this type of reporting, is a an  article about Tabata training I found in the Guardian. Its author wondered why not more people use this training style:

It’s slightly surprising […] that the plan is still the preserve of the serious athlete and musclehead crowd – although that may change now that Tabata has agreed a deal with Universal Studios that will lead to a network of instructors and a DVD range released towards the end of the year.

His own publication answered him only three weeks later, when it reported popular UK news anchor Andrew Marr suffered from a stroke after a high intensity rowing session:

Marr said he had followed the advice to “take very intensive exercise in short bursts – and that’s the way to health … I went on a rowing machine and gave it everything I had, and had a strange feeling afterwards – a blinding headache, and flashes of light – served out the family meal, went to bed, [then] woke up the next morning lying on the floor unable to move”.

High Intensity Exercise Takes Experience

High intensity or Tabata style exercise isn’t dangerous per se. That’s only when untrained people do it who don’t get straight As on their health exam and can’t read their bodies very well. Get a checkup and some solid cardio fitness under your belt and only then give it a go.

Jumping into HIIT or Tabata training without these prerequisites in place is reckless. It’s like handing a novice driver a Ferrari 458, telling him, “hey, it will get you from A to B much faster”.

Picture courtesy of Graeme Maclean.