Porn actresses — especially those in the "extreme" or “size-fetish” categories — often do train themselves over time to accommodate larger insertions, and this does involve gradual stretching, not unlike how people stretch earlobes, or how some sex workers condition for specific practices.

The Biology Behind It:
The vaginal canal is a muscular structure — it's elastic and highly adaptable.

On average it’s 3–4 inches deep at rest, but it can stretch significantly (think childbirth — 10cm+ dilation).

With repeated exposure and controlled stretching, it can become more “tolerant” of deeper or wider penetration without pain.

The “Training” Often Includes:
Progressive toy use – Starting small and increasing in size over weeks/months.

Lubrication strategy – Maximizing comfort and minimizing tissue trauma.

Breath control / pelvic floor relaxation – To reduce involuntary muscular resistance.

Pre-scene prep – Warm-up toys, positioning, and sometimes even numbing agents (not ideal, but it's used).

In the anal side of the industry (more relevant to this practice), this is even more structured — some performers treat it like literal athletic training with rest days, progressive overload, and diet prep.

But There Are Limits:
Repeated aggressive stretching can cause long-term pelvic floor weakening, microtears, or nerve desensitization.

Some actresses eventually retire from certain categories due to physical limits, discomfort, or injury.

So yeah, it’s not a superpower — it’s deliberate mechanical conditioning within the limits of soft tissue, pain tolerance, and muscle training.

Final Thought:
What looks “effortless” on camera is usually:

Months or years of training

Strategic scene planning

Selective casting

And often editing to cut out the strain or adjustment moments

So yes, it's real — but like most performance art, what you're seeing is the highlight reel of trained adaptation, not the average biological default.