A new study suggests you need to sweat for nine to ten hours every single week.
The numbers come out in the British Journal of Sports Medicine. The goal? Cut your risk of a stroke or heart attack significantly.
This is far above the standard advice. The World Health Organization recommends just 150 minutes. That is two and a half hours. Barely half a day.
Some experts think you should take this new research with a pinch of salt.
Sean Heffron is a cardiologist at NYU. He thinks the study’s authors are understating how much exercise actually helps. He disagrees with the math.
Here is what they did.
They looked at 17,00 people from the U.K. Bioback. They used accelerometers. Devices that track movement. For one whole week.
The finding? You need between 560 and 610 minutes of moderately vigorous activity. That is roughly nine to ten hours.
And it gets tougher for the unfit. If you aren’t already in shape, you might need another 50 minutes on top of that to get the same benefit as a fit person.
Compare that to the WHO guideline. 150 minutes drops risk by only 8 or 9 percent.
Heffron calls that “not nothing.”
If a drug worked that well we’d celebrate. He’s right to be annoyed. The gap between 9 percent and 30 percent feels like a missed opportunity.
Not a replacement for common sense
The new data doesn’t prove the WHO wrong.
Ulrik Wisløff knows this well. He leads cardiac research in Norway. He points out that 150 minutes was never the “best” number.
It was the “possible” number.
A public health floor. Something people can actually achieve without quitting on Monday.
There is also a problem with the method.
The design obscures how intense activity feels for different bodies.
Think about a walk around the block. For a 75-year-old that’s hard work. For a 25-year-old sprinter? Nothing. The accelerometer sees movement. It doesn’t feel your breath.
Wisløff notes we probably underestimate how much we move already. Gardening? Vigorous. Tennis? Count that. Breaking a sweat is the goal. You don’t need a gym membership to do that.
Intensity matters more than volume.
Previous studies showed just five minutes of hard work a day cuts mortality risk by 30% for inactive people. Small doses hit hard.
Then there’s genetics. The study ignores DNA. And it only looks at one week. Did those participants have a busy week? A weird week?
Heffron says he would ignore the part about unfit people needing to work harder.
It’s not a competition.
You won’t know who benefits most until they do the work.
Moving from zero to something always helps. No activity makes diabetes or high blood pressure worse. So just move.
Where do you draw the line between “enough” and “optimal”?
Nobody knows for sure. Maybe you just have to try.
