The 150-Minute Myth: Why Women’s Hearts Were Never Playing by the Rules
A groundbreaking Nature study reveals that women gain far more heart protection from far less exercise and exposes the quiet bias built into decades of health advice.
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How a Simple Exercise Rule Became a Universal Health Commandment
If you grew up in the 1990s, you probably remember the posters.
They were everywhere; school corridors, gym changing rooms, the nurse’s office, even the laminated information cards pinned to the wall next to the blood-pressure machine at the local pharmacy. Each poster said the same thing, in the same tone that adults used when handing out commandments disguised as advice:
“For a healthy heart: 150 minutes of moderate exercise per week.”
The number was pleasingly round, almost biblical in its certainty. It asked nothing about who you were, what your life looked like, or how your body responded to effort.
It didn’t ask whether you were a man or a woman, a teenager or a new mother, someone recovering from illness, someone juggling care work, or someone in the slow, foggy transition of perimenopause.
It simply declared itself onto the wall - a universal truth, as unshakeable as the food pyramid and the BMI chart.
For decades, the 150-minute rule shaped public-health messaging, clinical advice, wellness programs, and guilt-ridden New Year’s resolutions. It became the quiet metronome behind how people thought about movement and morality: a good person met the guideline. A careless one did not.
And then, this October, a study published in Nature Cardiovascular Research quietly lit that metronome on fire.
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Women Benefit More From Less Activity…Apparently
Researchers analysed accelerometer data from nearly 90,000 adults in the UK Biobank. Not self-reported exercise but actual movement captured through wrist-worn devices. They measured moderate to vigorous physical activity (MVPA) and tracked cardiovascular outcomes: coronary heart disease, mortality, overall cardiac risk.
And what they found was astonishing.
Women achieved the same, and in some cases, greater cardiovascular protection as men with substantially less exercise.
Where women reached around a 30% reduction in coronary heart disease at roughly 250 minutes of weekly MVPA, men needed more than 500 minutes for a comparable benefit.
Even more striking: among people with existing heart disease, women who met guideline levels of activity saw their risk of death drop by nearly three times more than men.
It wasn’t subtle. It wasn’t a small statistical footnote. It was a clear, measurable, sex-specific difference in how hearts respond to movement.
The female heart, it turns out, has been quietly playing by its own rules all along.
Why the 150-Minute Exercise Guideline Was Never Truly Universal
To understand why this study matters, you have to understand the lineage of the rule it challenges. The 150-minute guideline didn’t come from analysing sex-specific physiology. It came from epidemiological studies that, for most of the 20th century:
enrolled mostly men, or
analysed mixed groups without separating by sex, or
treated hormonal cycles as “complex variables” best avoided.
Cardiovascular research was deeply shaped by the assumption that men were the ideal model for early disease. The data built around them calcified into “universal” truths.
Public health loved the simplicity.
Clinicians loved the clarity.
Guideline committees loved the convenience.
And so a rule built upon a male-default dataset became the baseline expectation for everyone. A global prescription, distributed on posters and pamphlets, as if the human heart were a single organ with a single equation.
But the heart is not singular. And biology is not neutral.
The 150-minute rule wasn’t wrong for its time. It was merely incomplete and its incompleteness carried consequences.
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The Male-Default Problem: The Ideology Embedded in Public Health Guidelines
This Nature study does not just rewrite a recommendation. It exposes the ideology behind it.
For decades, medicine has been built on the pursuit of the neutral body - the idea that the fairest approach is the one that assumes sameness. In that worldview, difference is inconvenient. Difference is “noise.” Difference complicates the clean lines of research design, the tidy graphs of policy briefs, the elegant simplicity of public messaging.
And so the system smoothed over difference. Not maliciously or intentionally, but systemically.
It chose universality over accuracy.
Sameness over specificity.
Neutrality over truth.
The result?
We built a generation of health advice that was tidy on paper and imprecise in practice. And precision always wins. Eventually.
Why One-Size-Fits-All Exercise Advice Fails Women
Here is the uncomfortable cultural truth: We treat exercise guidelines like toothpaste flavour - the same for everyone. The incentive?
Simplicity → easy messaging → lots of posters. But simplicity comes with a cost.
It makes sex and gender biology invisible.
It ignores differential physiology.
It repeats, again and again, the quiet fiction that the male body is the baseline and everything else is merely variation.
We invest in “move more” messaging rather than “move in the way your biology responds to.” We emphasise minutes rather than effectiveness per minute, a distinction this study brutally exposes.
The culture loves uniformity. Bodies do not.
Implications for Public Health, Clinical Care, Innovation, and Capital
The implications stretch far beyond gym routines.
Public health must rethink universality
Guidelines that treat differences as footnotes are no longer adequate.
Sex-specific exercise recommendations are not niche. They are accurate.Clinicians must recalibrate prevention
A 52-year-old woman navigating perimenopause and a 52-year-old man with rising cholesterol should not receive the same advice. Their risk curves, hormonal states, metabolic responses, and inflammatory patterns diverge sharply.
Innovation must follow the evidence
There is now space, scientifically and commercially, for:
sex-specific cardiometabolic scoring
wearables that calibrate activity thresholds by sex and age
personalised exercise-as-medicine protocols
preventive tools rooted in female physiology, not generic guidelines
Capital will inevitably adjust
When evidence shifts the architecture of prevention, investment follows.
The future of cardiac innovation will be built by those who read this study not as trivia, but as signal.
The Hidden Emotional Cost of Universal Exercise Guidelines
But beneath all of this, beneath the science and the guidelines and the policy implications, is something quieter and more personal.
How many women internalised a sense of inadequacy because they didn’t meet the 150-minute target?
How many mothers, caregivers, and professionals carried a subtle guilt for not doing “enough”?
How many believed they were neglecting their health, when in reality their hearts were responding powerfully to far less?
This is the emotional weight of universal guidelines that were never universal. They don’t just shape behaviour. They shape identity. They shape self-perception. They shape the silent stories we tell ourselves about effort and failure.
What the Nature study reveals is not simply a new threshold for exercise.
It reveals how deeply a simple number can embed itself into the psyche through repetition not accuracy.
This Essay Mirrors the Problem It Critiques
Which brings me to the irony. Here I am, writing yet another guideline-like piece; a narrative about how women should think differently about exercise. Which means in essence, I am guilty of the very thing I’m critiquing.
But I’m doing it intentionally.
Because my point is not to replace one universal rule with another. The point is to dismantle the idea that universal rules were ever universal. So I am not prescribing a number. I am prescribing a question:
What if your body has always been speaking in a different language and medicine simply handed you the wrong dictionary?
Toward a More Precise, Humane, Sex-Specific Future of Heart Health
Maybe the evolution of medicine is not the discovery of new knowledge, but the courage to return to what should have been obvious:
that biology is diverse,
that precision is humane,
and that specificity is a form of respect.
Maybe the future of prevention is not more discipline but more understanding.
And maybe the female heart has been trying to tell us something for decades in its efficiency, in its resilience, in the way it responds to movement with a different rhythm, a different logic, a different intelligence altogether.
The 150-minute myth belonged to a world that believed simplicity was fairness. The world we need now demands something more honest:
Stop pretending the bodies are the same.
Start building the systems that know they are not.
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Disclaimer & Disclosure
This content is for informational and educational purposes only. It does not constitute financial, investment, legal, or medical advice, or an offer to buy or sell any securities. Opinions expressed are those of the author and may not reflect the views of affiliated organisations. Readers should seek professional advice tailored to their individual circumstances before making investment decisions. Investing involves risk, including potential loss of principal. Past performance does not guarantee future results.
References
Primary Nature Study
Li, X., Macfarlane, P., & Gill, J. R. (2025). Sex-specific associations between accelerometer-measured physical activity and cardiovascular outcomes in UK Biobank. Nature Cardiovascular Research, 4(10), 1452–1468. https://doi.org/10.1038/s44161-025-00732-z
UK Biobank Dataset Reference (optional but helpful)
Sudlow, C., Gallacher, J., Allen, N., Beral, V., Burton, P., Danesh, J., ... & Collins, R. (2015). UK Biobank: An open access resource for identifying the causes of a wide range of complex diseases of middle and old age. PLoS Medicine, 12(3), e1001779. https://doi.org/10.1371/journal.pmed.1001779
Historical Context on Sex Bias in Medical Research
Holdcroft, A. (2007). Gender bias in research: How does it affect evidence-based medicine? Journal of the Royal Society of Medicine, 100(1), 2–3. https://doi.org/10.1177/014107680710000102
Cardiovascular Sex Differences (background research)
Regitz-Zagrosek, V. (2012). Sex and gender differences in health. Science & Society Series on Sex and Science. EMBO Reports, 13(7), 596–603. https://doi.org/10.1038/embor.2012.87
Exercise Guidelines (WHO / global standard)
World Health Organization. (2020). WHO guidelines on physical activity and sedentary behaviour. Geneva: WHO Press. https://www.who.int/publications/i/item/9789240015128
Food for thought - If this one guideline was wrong for decades, what does that tell us about the systems that shape women's health today?
What do you think needs to happen for public health guidelines to finally stop treating women as "variations" of men?