Women, breathing, physiology

At adolescence, hormonal differences between girls and boys set the stage for a lifetime of distinct physiological patterns — especially when it comes to breathing and energy regulation.

Girls begin menstruating. With this comes regular blood loss, and with each cycle, a loss of iron — the essential mineral needed to build hemoglobin in red blood cells. Women throw this iron out monthly. Over time, this leads to lower total iron stores and lower hemoglobin levels, meaning less oxygen can be carried in each millilitre of blood.

To compensate:

- The heart rate increases to circulate the available oxygen more quickly,

- The breath rate increases to draw in more oxygen per minute.

This creates a higher baseline “rev rate.” Women are idling faster, physiologically, even at rest. But the compensation comes at a cost: less oxygen reaches the core organs, especially the brain. The result is:

- A lack of steadiness,

- Increased forgetfulness,

- More frequent anxiety,

- Heightened feelings of insecurity.

This pattern often hits young women suddenly and profoundly in their late teens, as iron demands rise with growth, activity, and ongoing menstrual cycles. The world might label it emotional instability — but underneath, it is often a physiological overload.

Over time, this shapes a chronic breathing pattern — one that’s often misread as stress, anxiety, or volatility. But the truth is more grounded: women are physiologically tuned to run leaner. Less oxygen per unit of blood means higher circulatory effort is required just to meet basic demands.

Boys, on the other hand, receive a surge of testosterone during puberty. This increases their muscle mass, boosts red blood cell production, and enhances overall oxygen-carrying capacity. The result is a bigger engine: greater aerobic output, slower resting heart and breath rates, and more physiological resilience under stress.

This contributes to the narrative that men are more steady, more capable under pressure — but this is not about character. It is about circulation.