The Question: Is there any difference in training men vs women, and will that be covered in the course?

At first, my gut reaction was “nah, not really”—but then, because I refuse to let a stone go unturned, I started digging.

And wouldn’t you know it, a new study dropped in Medicine & Science in Sports & Exercise that might flip this whole thing on its head (1).

So buckle up, grab some coffee (or ketones, if you're feeling fancy), and let's get weird as we go hard down the nerd chute.

The Study: The Battle of the Sexes (But Make It Cardio)

Researchers took 38 women and 26 men and had them complete:

12 weeks of endurance (END) training aka cardio

12 weeks of resistance (RES) training aka lifting

12-week washout period in between aka time to get back to baseline

The goal? See how men and women adapt differently to both types of training.

And the results? Spicy.

First up, let’s check if their endurance program actually worked (because if it didn’t, this whole study would be a rolling dumpster fire, and we can end this tyrant here).

✅ VO₂ max increased significantly after endurance training

❌ No real changes after resistance training

Endurance training results: +3.61 mL·kg⁻¹·min⁻¹ (p < 0.001)

Resistance training results: Δ 0.03 mL·kg⁻¹·min⁻¹ (p = NS)

Translation?

Cardio works.

Shocker, I know.

Plus, more data shows that lifting alone won’t magically increase your aerobic capacity.

What The Hell Did They Actually Do?

The Endurance Training (a.k.a. how they built their cardio engine)

3 sessions per week

2 running sessions + 1 cycling session per week

Progressive intensity:

Started at 60% HR max, worked up to 90% HR max

Increased from 15 minutes per session to 60 minutes over 12 weeks

Structured periodization—three 4-week phases

The Resistance Training (a.k.a. how they built their strength)

3 sessions per week

Big lifts:

Bench press, military press, squats, deadlifts, leg press

Progressive overload:

Started at 60% of 1RM, worked up to 90% 1RM

Structured periodization—four 3-week phases

Now, let’s get to the juicy part.

Men vs Women: The Cardiac Adaptation Showdown

1️⃣ Men showed greater left ventricular hypertrophy from resistance training

2️⃣ Women had better diastolic function improvements from endurance training

3️⃣ Hormonal differences likely played a role

In plain English:

✔ Men’s hearts got bigger from lifting (which isn’t necessarily a good thing)

✔ Women’s hearts became more efficient with cardio

✔ Testosterone vs estrogen likely influenced these adaptations - but we are not sure on that yet

✔ Men tend to burn more glucose during training, while women favor fat oxidation

What This Means for Your Training

🚹 If you’re a dude:

Lifting increases cardiac mass but may negatively affect diastolic function over time

This suggests that men need to prioritize cardio more than they think

My bias here - if you are a male using high levels of TRT, cardio is even more important (but this was not the focus of this study)

🚺 If you’re a woman:

Endurance training improves diastolic function

Resistance training doesn’t seem to alter cardiac structure much

This suggests that women might get away with slightly less cardio for heart health

The Strengths of This Study

✅ Randomized crossover design—everyone did both programs, so genetics weren’t a factor

✅ Supervised training sessions—so no one was sandbagging

✅ High adherence rates (94-95%)—meaning the results actually mean something

✅ Matched intensities for men and women—so we aren’t comparing apples to oranges

But It’s Not Perfect… Here Are The Limitations

❌ Only 12 weeks of training—cardiac adaptations often take longer

❌ No elite athletes—so the results may not apply to high-level endurance or strength athletes

❌ No hormonal analysis—which is a huge missing piece, thus the hormonal piece is se

❌ Used echocardiography instead of MRI—so the structural changes aren’t as precise

So, while this study is solid, it’s still just one piece of the puzzle.

Final Thoughts (And Why You Should Care)

This study doesn’t give us a clear-cut roadmap on how to modify training for men vs women..

...but it does hint that there are sex-based differences in how we adapt to endurance and resistance training.

What we do know from this study:

✅ Men and women adapt differently to cardio and lifting

✅ Cardio improves VO₂ max—lifting alone won’t do it

✅ Strength training causes greater left ventricular mass increases in men, so cardio is even more important for them

✅ Women see more diastolic function improvements from cardio, so they might need slightly less

What’s Next?

I’m doing a deep-dive breakdown of this study inside the Flexible Meathead Cardio course because I want to see if I can extract even more practical insights for how to optimize training for both men and women.

I’m also running a full literature search to see if any other hidden gems can add to this picture.

For now, the key takeaway?

Keep lifting, but stop ignoring your cardio.

​https://miket.me/cardio​​

Much love and oxygen-fueled gains,
Dr. Mike

References

1) Naylor, L. H., Marsh, C. E., Thomas, H. J., Maslen, B. A., Collis, J., Lester, L., & Green, D. J. (2025). Impact of sex on cardiac functional adaptation to different modes of exercise training: A randomized crossover study. Medicine & Science in Sports & Exercise. Advance online publication.

Hat tip to Dr Bradley Holmer, who did a great write-up on this study for the Physiologic Speaking substack.

PS - The FMC course is closing tonight at midnight PST.

​https://miket.me/cardio​​

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_____________________

Mike T Nelson CISSN, CSCS, MSME, PhD
Associate Professor, Carrick Institute
Owner, Extreme Human Performance, LLC
Editorial Board Member, STRONG Fitness Mag

Mike T Nelson is a PhD and not a physician or registered dietitian. The contents of this email should not be taken as medical advice. It is not intended to diagnose, treat, cure, or prevent any health problem - nor is it intended to replace the advice of a physician. Always consult your physician or qualified health professional on any matters regarding your health.

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