Current guidelines establish a baseline, not optimal protection
For generations, public health has offered a simple covenant with the body: move for 150 minutes each week, and the heart will be safer. Now, researchers from the University of Macau, drawing on nearly a decade of data from thousands of British adults, suggest that covenant may have been written too modestly. Their findings, published in the British Journal of Sports Medicine, indicate that genuine cardiovascular protection — a reduction in risk exceeding 30 percent — demands not 150 minutes of weekly exercise, but closer to nine or ten hours, inviting a broader reckoning with what we truly owe our hearts.
- Current WHO guidelines of 150 weekly minutes, long treated as sufficient, may offer only an 8-9% reduction in cardiovascular risk — a margin researchers now describe as modest at best.
- Across 7.8 years of follow-up, 1,233 cardiovascular events among 17,088 participants revealed a stark gap between what guidelines promise and what the data actually shows.
- To cross the threshold of meaningful protection — 30% or greater risk reduction — participants needed to exercise 560 to 610 minutes weekly, a target only 12% of the study group reached.
- Fitness level shapes the equation: less conditioned individuals needed 30 to 50 extra weekly minutes compared to fitter peers to achieve the same cardiovascular benefit, pointing toward personalized targets.
- Researchers are now calling for a two-tier guideline system — one floor for basic safety, one higher bar for genuine protection — tailored to each patient's fitness and motivation rather than applied uniformly.
A research team from the University of Macau has published findings in the British Journal of Sports Medicine that quietly unsettle one of public health's most familiar recommendations. The widely endorsed target of 150 minutes of weekly moderate-to-vigorous exercise, they argue, delivers only an 8 to 9 percent reduction in cardiovascular risk — a benefit the researchers characterize as modest, regardless of a person's baseline fitness.
The study drew on data from 17,088 UK Biobank participants tracked between 2013 and 2015, with an average age of 57. Each wore a wrist device for seven days to capture real-world activity patterns and completed a cycling test to estimate VO2 max — a measure of how efficiently the body processes oxygen under exertion. Over a follow-up averaging 7.8 years, 1,233 cardiovascular events occurred, including 874 cases of atrial fibrillation, 156 heart attacks, 111 instances of heart failure, and 92 strokes.
The pattern that emerged was striking: achieving a cardiovascular risk reduction above 30 percent required between 560 and 610 minutes of weekly exercise — three to four times the standard recommendation. Only 12 percent of participants reached that threshold. The study also found that individual fitness matters: less conditioned people needed roughly 30 to 50 additional weekly minutes compared to fitter individuals to reach equivalent protection.
The researchers are candid about the study's limits — it is observational, the sample skewed healthier than the general population, and VO2 max was estimated rather than directly measured. Still, they argue the findings call for a fundamental shift in how guidelines are communicated: not a single universal target, but a two-tiered framework distinguishing the minimum exercise needed for basic safety from the substantially higher volumes required for meaningful risk reduction — and ideally, targets calibrated to each person's own fitness and goals.
A team of researchers from the University of Macau has challenged the adequacy of current exercise guidelines, arguing that the widely recommended 150 minutes of weekly physical activity provides only modest protection against heart disease. Their analysis, published in the British Journal of Sports Medicine, suggests that substantially more exercise is needed to achieve meaningful cardiovascular benefit—somewhere between 560 and 610 minutes per week, or roughly nine to ten hours.
The study examined data from 17,088 participants in the UK Biobank who were tracked between 2013 and 2015. The average age was 57; 56 percent were women, and 96 percent identified as white. Each participant wore a wrist device for seven consecutive days to record their typical exercise patterns and completed a cycling test to estimate their maximum oxygen uptake, or VO2 max—a key measure of how efficiently the lungs, heart, and muscles work together to process oxygen during intense exertion. Researchers also collected information on smoking, alcohol consumption, perceived health and diet, body mass index, resting heart rate, and blood pressure.
Over an average follow-up period of 7.8 years, 1,233 cardiovascular events occurred among the group. These included 874 cases of atrial fibrillation, 156 heart attacks, 111 instances of heart failure, and 92 strokes. When the researchers analyzed the relationship between exercise volume and these outcomes, a striking pattern emerged. Those who met the current public health recommendation of 150 minutes of moderate to vigorous activity per week—brisk walking, running, cycling—experienced only an 8 to 9 percent reduction in cardiovascular risk. This modest benefit held true regardless of a person's baseline fitness level.
To achieve what the researchers defined as substantial protection—a reduction in risk exceeding 30 percent—participants needed to exercise between 560 and 610 minutes weekly. That is three to four times the standard recommendation. Yet only 12 percent of the study population reached this threshold. The findings also revealed an important nuance: people with lower baseline fitness required approximately 30 to 50 additional minutes of weekly exercise compared to those already in better condition to achieve equivalent benefits. For instance, to cut cardiovascular risk by 20 percent, less fit individuals needed 370 minutes of exercise per week, while those with higher fitness levels needed only 340 minutes.
The researchers acknowledge several limitations. This was an observational study, meaning cause-and-effect cannot be definitively established. The participants may have been in better overall health than the general population. Additionally, VO2 max was estimated rather than directly measured, and the study did not track sedentary time or lower-intensity activity. Despite these constraints, the team argues that their findings support a recalibration of public health messaging. Current guidelines, they contend, establish a reasonable baseline for cardiovascular safety but fall short of optimal protection. They propose that future guidelines should distinguish between the minimum volume of exercise needed for basic safety and the substantially higher volumes required for meaningful risk reduction. Importantly, they suggest these targets should be personalized based on individual fitness levels and motivation, allowing clinicians to counsel patients more precisely about what their own hearts actually need.
Citações Notáveis
Future guidelines should distinguish between minimum exercise for basic safety and substantially higher volumes for optimal cardiovascular risk reduction— University of Macau research team
A Conversa do Hearth Outra perspectiva sobre a história
Why does the study suggest we need so much more exercise than current guidelines recommend? Is 150 minutes simply wrong?
It's not that 150 minutes is wrong—it's that it's a floor, not a destination. The guidelines were designed to give everyone a baseline of protection. But this study shows that baseline is modest, around 8 or 9 percent risk reduction. If you want real protection, you need to go much further.
But only 12 percent of people in the study hit that 560-minute target. Isn't that discouraging?
It is, but the researchers see it differently. They're not saying everyone must exercise nine hours a week. They're saying the people who are motivated to do so—who have the time, the ability, the drive—deserve to know what actually protects their hearts. Right now, we tell everyone the same thing. This suggests we should be more honest about what different levels of effort actually buy you.
The study mentions that less fit people need more exercise to get the same benefit. How does that work?
Your baseline fitness matters. If you're already in good cardiovascular shape, your body is more efficient at processing oxygen and protecting itself. Someone starting from a lower fitness level has to work harder and longer to build that same protection. It's not unfair—it's just physiology.
Is this study definitive? Can we trust it?
It's solid but not perfect. It tracked real people over years and recorded actual heart events, which is strong. But it's observational, not experimental. And the fitness measure was estimated, not measured directly. The researchers are careful about that. They're not claiming they've found the absolute truth—they're saying the current guidelines need rethinking.
What changes if doctors actually listen to this?
Instead of one-size-fits-all advice, you'd get personalized targets. A doctor could say: "If you want basic protection, 150 minutes works. If you want substantial protection and you're willing to commit, here's what you need based on your current fitness." It respects both the person who can only do the minimum and the person who wants to do more.