Katie Harvey

I'm very good at doing too much.

It took me a long time to realise that wasn't the same thing as being good at high performance.

High-performance coach, speaker, author and founder of b.reathe. This work didn't start with a coaching qualification. It started with my body.

Where it started

Nearly 17.

After months of exhaustion, weight loss and symptoms I'd learned to push through, I collapsed.

Diagnosed with Addison's Disease. A rare condition affecting the body's production of essential hormones, including cortisol.

I was given medication. I got my energy back.

"Right. Better make the most of it."

The short version

16Started an electrical apprenticeship.
Almost 17Diagnosed with Addison's Disease.
20Qualified electrician. Started a business.
23Left the tools.
2026Published The Success Hangover. Amazon UK No.1 in two categories.
TodaySpeaker, author and high-performance coach. Property operator managing 57 rooms.

I've experienced four adrenal crises. Surviving the first didn't magically make me good at listening to my body.

That's why I don't present myself as someone who has solved performance. I'm obsessed with understanding it.

I read the research. I speak to experts. I collect data. I change my mind when better evidence tells me to. I don't want to become a wellness guru.

How much can a human being
sustainably hold?

Muay Thai

Muay Thai taught me something business never could. You cannot bullshit your body in a fight.

I've fought twice. One win, one loss. The loss taught me more. I entered depleted and tried to compensate with determination. It didn't work.

You can't mindset your way out of missing capacity.

Baseline before brilliance.

Recovery is part of performance.

You can be capable and at capacity.

Don't lower the goal. Raise your capacity.

The methodology, from the book

Speaking