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Olsen Fitness, Personal Trainer Cardiff



Kier Olsen - Head Personal Trainer/Transformation Coach

Kier is a highly sought after Level 4 Personal Trainer/Strength and Conditioning Coach, with a degree in Sport & Exercise Science which helps him lead advanced personal training sessions, using what he has learnt from Exercise Psychology, Biomechanics, Physiology and Exercise Nutrition. These methods combined with years of studying, expansive experience in helping people achieve their goals and a genuine passion for changing people’s lives are what have driven OlsenFitness to be one of the fastest growing Personal Training/Coaching services in Cardiff.

Kier has achieved incredible results with a wide range of clientele from all walks of life since establishing OlsenFitness. Some of these include athletes that represent their country in their given sport, actors and actresses, directors, producers, musicians and models. He has been recognised with a top ranking position in personal trainers throughout Cardiff, a Cardiff Life Health Award in 2017 and nominated for the Fitness Award at The Elite Awards 2018.

Kier is also regularly invited to run talks, seminars and workshops at Universities and Schools across Wales. He has run workshops for Welsh Government, among other corporate sectors and businesses. Kier has also worked with Whitchurch Hockey Club as their Strength and Conditioning Coach for three years, improving their players overal match fitness and conditioning. This season the womens and mens teams have won two major european tournaments. He also runs fitness retreats in Marbella which aim to give those who attend the tools to start their transformation both through training and education. 

Since establishing OlsenFitness Kiers main goal has always been to help people achieve their goals through sustainable and effective methods, whilst finding an enjoyment for fitness and a healthy, happy lifestyle. 






  • testimonials 1
    I was negative about my self, I would keep putting myself down and finding faults but kier has made me see myself in a much more positive way and I can't believe how much I have changed in both body shape and attitude to my fitness.

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  • Testimonial 2
    Kier is a great ambassador for fitness and healthy living and has been influential in increasing fitness levels and improving technique for Whitchurch Hockey Club

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  • Testimonial 3
    My approach and knowledge towards fitness has completely been turned on it's head and my life has changed as a result

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  • Testimonial 4
    I am fit, healthy and confident, Kier is always with me setting my self new goals to achieve. He is not only my trainer but also now a friend and I would highly recommend him!

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