FUNDAMENTALS

Cardio Isn't Enough Anymore - Why Women Over 40 Need Strength Training Too

Running, cycling, swimming - for years the reliable answer to "What am I doing for my health?" After 40, that answer becomes incomplete.

10 Reps Editorial

September 3, 20264 MIN READ

Cover image: Cardio Isn't Enough Anymore - Why Women Over 40 Need Strength Training Too

Running, cycling, swimming - for years the reliable answer to "What am I doing for my health?" After 40, that answer becomes incomplete. Not because cardio is useless - but because it leaves one area completely untouched, exactly the one that needs the most attention right now.

What cardio is actually good at

In fairness: endurance training isn't a bad choice. It strengthens heart and circulation, and even for bone density, research shows real, measurable effects from cardio - stronger than long assumed. Anyone who runs or swims regularly is doing something genuinely good for their body.

The gap cardio doesn't close

And yet one area stays completely untouched: muscle mass and strength. Starting around age 30, muscle mass declines continuously, and menopause further accelerates this process in women. Cardio training barely slows this loss - it simply lacks the type of load the muscle needs for growth and strength gains. A runner who has trained for years often has excellent endurance and still noticeably weaker strength.

That's not a footnote. Loss of strength is a stronger risk factor for falls and reduced everyday resilience than the loss of muscle mass itself. And that's exactly the area only strength training addresses.

Combined beats either alone

For bone density specifically: neither cardio nor strength training alone gets the maximum effect - the combination of both shows the most consistent and strongest effects across several recent reviews. Doing both covers two different mechanisms acting on bone, and adds what cardio alone can't deliver: muscle preservation.

The clear conclusion: cardio isn't a mistake - but sticking to endurance training alone leaves one of the most important areas after 40 completely unaddressed.

What this means for your practice

Don't cut cardio, add to it. Endurance training stays valuable - just not as the only solution.

Schedule strength training at least twice a week, focused on compound exercises that load multiple muscle groups at once.

Alternate or combine both. The strongest effects on bone density show up when both training forms are part of the routine.

Take muscle strength seriously as its own progress metric - not just endurance times or kilometers run.

OUR APPROACH AT 10 REPS

10 Reps is built exactly for the gap that cardio alone leaves open. The app delivers structured strength training plans built around the compound exercises that do the most for muscle preservation and bone density - as a complement to existing endurance training, not a replacement for it.

The ProgressionEngine makes sure load increases in a traceable way from session to session, whether strength training is completely new to you or has been part of your routine for a while.

Conclusion: Not either-or, but both

Cardio alone was never wrong - but after 40, what it can't do becomes visible. Muscle strength and mass can only be maintained through targeted load, which only strength training delivers.

Combine both, and you get demonstrably more than the sum of the individual effects - for bone, muscle, and your everyday resilience alike.