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Hi, my name is Claire Marsh (nee Hamer).

I'm a fitness athlete, coach and mentor.  Along with my husband, I own and manage The Box Portsmouth which is a specialist fitness facility for CrossFit and dance enthusiasts.

I have had a love of sport and physical activity since I was born (pretty much!) and have three decades of experience in various competitive sports.

I'm passionate about sharing the wealth of my knowledge and experience to help others achieve their absolute best.

As a teenager I represented Wales as an artistic gymnast at the XV Commonwealth Games.  In my twenties I performed as a dancer at various high profile events including the London 2012 Olympics Closing Ceremony.  In my thirties and to this day I enjoy competing as a CrossFit athlete.

From helping toddlers learn the basics of movement to developing world champion athletes I have trained hundreds of people of all ages and abilities to achieve their desired fitness and sporting goals.

Alongside my sporting endeavours I also have a degree in European Management Science and spent several years working as a chartered management accountant.

My Mission


I dream of a happier and healthier world where we live a fulfilled, enjoyable life through the freedom of movement. Where physical activity, pursuits and adventures are the best and most looked forward to part of everyone’s day.

It is my aim to encourage and inspire ALL to fulfil their true mental and physical potential.  Through teaching others to use fitness as a mechanism to unlock personal potential, build confidence and improve self esteem and to then transfer these skills into other aspects of life.

My Story


In my Teens

In my 20s

In my 30s

In my 40s

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