A few weeks ago, in his post “Focused Intensity”, Brian mentioned that –

“…the idea that 30 minutes of cardio a day will reduce your risk of heart disease has been proven to be inadequate”.

This caused a number of people to ask “Wait, working out 30 minutes is worthless?”

Hardly.  Thirty minutes is certainly better than nothing and no one is discounting it for general wellbeing, however 30 minutes being all you need for heart health isn’t enough. Here’s the story.

For years the American Heart Association has recommended that adults engage in at least 2 hours and 30 minutes per week of exercise (such as brisk walking) to help reduce the risk of heart disease. Unfortunately two important words were glossed over in their recommendation, and they were these –

“at least”

and somehow, over the years, 2 hrs and 30 mins per week (which works out to 30 minutes per workout) became a magic number. Work out for 30 minutes and you’ll have a healthy heart!

Or not.

Actually, it’s not.

A recent paper published in the journal Circulation showed that a study of the old 30 minute a day adage, while not bad, didn’t measure up. Now, a lot of times when you hear about studies, it’s a good thing to ask all kinds of questions about its thoroughness (we won’t get into population, sample, and dozens of other factors to take into consideration), but if we cut to the chase and look at extensiveness and length of time of the study, this one is pretty good. You know how you hear about studies that say something like “85% of those studied show that eating fast food is healthy for you!” and if you look at the study you find out that it only involved 25 people, all of whom work for, or are family members of, the fast food company funding the study?

This wasn’t one of those.

This study involved 370,460 men and women and was conducted over a period of 15 years. And guess what they found out? That’s right, 30 minutes a day, while not worthless, is not enough to make a measurable impact in preventing heart disease. Of course there are a multitude of variables here such as what level of intensity are we talking about, and on and on. But the message is clear.

You should exercise longer than 30 minutes to reduce your risk of heart disease.

Obligatory disclaimer section: Always consult with your doctor about your workout plans. If you’re just starting out, 30 minutes or maybe longer than 30 mins could be more than your doctor would recommend. But if you’re good to work out, strive for more than 30 minutes, be focused in your workout, and get the most that you can out of it.