Strong Her - Rethinking Women’s Fitness Through the Lens of Physiology

Women who strength train regularly have a 30% lower risk of cardiovascular-related death than those who don't - nearly three times the benefit recorded in men doing the same exercise. (Journal of the American College of Cardiology, 2024)

Women reach the same mortality benefit as men with less than half the exercise volume - 140 minutes of moderate aerobic activity per week versus 300 minutes for men. (Journal of the American College of Cardiology, 2024)

Only 20% of women complete a weekly strength training session - despite it being the category of exercise from which they stand to gain the most. (Journal of the American College of Cardiology, 2024)

Eight million of the estimated 10 million Americans living with osteoporosis are women - a figure directly linked to the decline in oestrogen at menopause and insufficient resistance training. (Bone Health and Osteoporosis Foundation)

Much of the foundational research underpinning exercise science conducted a few decades ago relied predominantly on male subjects.

The training and nutrition guidance that followed was built on that evidence base - and for a long time, assumptions that worked for men were simply applied to women.

The result has been a persistent gap between what women are told works and what the science, built around their actual physiology, shows.

That gap is closing.

And the findings demand serious attention.

The Physiology Gap

Women’s bodies are governed by hormonal cycles that directly influence energy levels, strength, recovery and mood.

Oestrogen, progesterone, testosterone (yes, women produce it too), cortisol and thyroid hormones interact in patterns that shift weekly, monthly and across decades.

The menstrual cycle alone creates distinct phases - the follicular phase, ovulation and the luteal phase - each with measurably different effects on how muscles respond to training, how the body uses fuel and how quickly it recovers.

During the follicular phase, rising oestrogen supports better neuromuscular efficiency and faster recovery, making it a naturally productive window for higher-intensity work.

The luteal phase, by contrast, raises core body temperature and increases perceived exertion, which is why the same session can feel considerably harder in the days before menstruation.

These are not excuses or inconveniences.

They are physiological realities that well-designed training should account for - and rarely does.

The picture grows more complex as women move through perimenopause and menopause.

The decline in oestrogen does not simply affect reproductive function; it directly impacts bone density, muscle mass and cardiovascular risk.

Understanding this should reshape how women approach fitness at every stage of life, not only the decades when gym culture concentrates its marketing.

The Resistance Training Revolution

Perhaps the most persistent myth in women’s fitness is the fear of lifting weights.

Concerns about becoming too muscular have kept generations of women away from the weights room, steering them instead towards exclusively cardio-based exercise.

The science offers a very different picture.

A 2024 study published in the Journal of the American College of Cardiology, funded in part by the National Heart, Lung, and Blood Institute (NHLBI), followed over 400,000 adults across a 20-year period.

Women who did regular strength training had a 30% reduced risk of cardiovascular-related death - nearly three times the benefit seen in men doing the same training.

That figure bears repeating: the same exercise, performed by women, delivered almost triple the heart-protective effect.

The aerobic exercise data tells a similarly compelling story.

Women achieve the equivalent mortality benefit of men with considerably less training time - just 140 minutes of moderate aerobic exercise per week, compared to 300 minutes for men.

As cardiologist Susan Cheng, one of the study’s co-authors, put it:

“Taking some regular time out for exercise, even if it’s just 20 to 30 minutes of vigorous exercise a few times each week, can offer a lot more gain than they may realise.”

This matters all the more given that only 33% of women in the study met the standard for weekly aerobic exercise, and just 20% completed a weekly strength training session.

Women, it turns out, are getting less of an activity that benefits them more.

Muscle As Medicine

Muscle tissue is metabolically active.

It supports insulin sensitivity, protects joints, maintains posture and, critically for women, helps preserve bone density.

Of the estimated 10 million Americans with osteoporosis, around eight million are women, according to the Bone Health and Osteoporosis Foundation.

The reasons are biological: women tend to have smaller, thinner bones, and the sharp decline in oestrogen at menopause accelerates bone loss significantly.

Regular resistance training, paired with sufficient protein intake to support muscle repair and growth, is one of the most evidence-based interventions available for countering this.

The mental health picture is equally well-documented.

Exercise promotes the release of serotonin and dopamine - the neurochemicals central to mood regulation - a mechanism with strong support across decades of neuroscience research.

A controlled study published in the Journal of Psychosomatic Research examined 60 postmenopausal women experiencing anxiety and depression.

Those in the exercise group saw an 18 to 22% improvement in symptoms.

Those who did not exercise showed no improvement at all.

Sleep quality responds similarly, with research demonstrating improvements in how quickly people fall asleep, total sleep duration and frequency of night-waking - benefits that extend across exercise modalities, from high-intensity interval training to brisk walking.

Strength Across Life Stages

Building functional strength is not about aesthetics.

It is about long-term physical capability and quality of life.

When a woman’s body is well-conditioned and properly fuelled - with adequate protein to support muscle synthesis, the right micronutrients to underpin hormonal health and targeted recovery nutrition to manage inflammation - the gains are felt in concrete ways.

Carrying shopping, keeping pace with children, climbing stairs, maintaining balance as we age: all of these depend on a muscular system that has been consistently trained and supported.

The science is unambiguous.

Women respond powerfully to resistance training, require less exercise volume to achieve the same cardiovascular benefits as men and stand to gain enormously from a nutrition strategy built around their physiology rather than borrowed from someone else’s.

The training and nutrition models that have shaped this conversation for decades were not built with women’s biology in mind.

The evidence has moved on considerably.

The industry - and the women it serves - should follow.

Editor’s Note On Sources

140-minute exercise threshold and 30% cardiovascular death risk reduction: Journal of the American College of Cardiology (2024), funded by the NHLBI/NIH

Osteoporosis statistics: Bone Health and Osteoporosis Foundation / FDA

Exercise and mental health in postmenopausal women (18-22%): Journal of Psychosomatic Research (Pubmed ID: 22409782)

Sleep and exercise: peer-reviewed literature across multiple study types

Author Bio

Andy Moore holds an MSc in Dietetics and is currently the Research & Development and Quality Control Manager at NPL.

She spearheads new product development for FMCG and pharmaceutical brands within the NPL group, including CAMs, sports supplements, and vitamins.

Andy’s role involves sourcing ingredients, developing product concepts, and overseeing packaging in collaboration with the Creative Director.

She ensures compliance with food safety and pharmaceutical regulations (SAHPRA) and supports strategic product launches with technical insights.

Passionate about wellness and nutrition, Andy’s extensive experience in R&D, commercial strategy, formulation development, and QA management drives her commitment to improving consumer health and wellbeing.

Her past roles include key positions at Glowing Sky Distributors, Powdermix Technologies, and USN SA - Ultimate Sports Nutrition.

https://www.npl.za.com/