Scientists looked at how much activity adults need to protect their hearts. They discovered that the usual advice of 150 minutes a week may not be enough.
The researchers saw big heart benefits when people did about 560‑610 minutes of moderate‑to‑vigorous exercise each week. That is roughly three to four times the current guideline.
Moderate‑to‑vigorous activities are things like brisk walking, running, or cycling.
Fitness Level Changes the Goal
The study also showed that people who are less fit might need a bit more activity than very fit people to get the same heart protection.
Because fitness varies a lot, a one‑size‑fits‑all rule may not work well. Future advice could give different targets based on how fit someone is.
Good cardiorespiratory fitness means the heart, lungs, and muscles work together efficiently. Low fitness is linked to higher chances of heart attacks, strokes, and early death.
How Fitness Was Measured
Researchers used a test called VO₂ max to estimate how well the body uses oxygen during hard exercise. Higher VO₂ max values mean better heart‑lung fitness.
The team studied 17,088 adults from the UK Biobank. Participants wore a wrist sensor for a week to track their daily movement and did a cycling test to estimate VO₂ max.
They also recorded other health factors such as smoking, alcohol use, diet, body weight, resting heart rate, and blood pressure.
Heart Events Recorded
Over an average of 7.8 years, 1,233 heart‑related problems happened, including atrial fibrillation, heart attacks, heart failure, and strokes.
People who met the 150‑minute guideline had only an 8‑9% lower risk of these events.
To cut risk by more than 30%, the study found you need the 560‑610 minutes of activity each week. Only about 12% of participants reached that level.
Less Fit People Need More Exercise
Those with the lowest fitness had to add about 30‑50 extra minutes per week compared with the fittest group to see the same benefit.
For example, a 20% risk drop required about 370 minutes per week for the least fit, while the most fit needed only about 340 minutes.
Study Limits
Because the research was observational, it cannot prove that more exercise directly caused lower heart risk.
Participants were generally healthier than the whole population, fitness was estimated rather than measured directly, and the study did not look at sitting time or light activity.
Even with these limits, the results support the current minimum recommendation and suggest that stronger, personalized guidelines could help people gain extra heart protection.