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Brutal Events Swim Start



It was the summer of 2012 and the Olympics had come to London. Already a keen runner I watched in awe as the best athletes from all over the world competed in various sports for the ultimate prize of a gold medal. One event in particular stood out... the triathlon.

I was inspired and that’s where my journey began.


Just a few weeks later, I purchased my first road bike and began swimming at my local pool with the intention of completing my first triathlon the next year… Fast forward to the current time and I have now completed numerous triathlons over various distances including Ironman, Double Extreme Ironman, Ultraman, and have also represented Team GB at World and European Age Group level. I have achieved the allusive sub 10 hour Ironman finish time and raced in the Ironman World Championships.


In order to improve my own performances I researched and studied various training methods and programmes already in existence and have gone on to build my own extensive training library. Since beginning my coaching journey with my local club Havering Tri, I have developed both as a coach and as an athlete. In 2018 was appointed Head Run Coach. I am passionate about coaching and strongly believe in a personal and bespoke approach for all of the athletes I coach.

With a young family and full time job, I understand the pressures involved with work, family and social commitments. Therefore, I will develop a time efficient plan which fits around your personal circumstance taking these factors into account. This plan will focus on ‘quality over quantity’ and look to make the most out of every session.

Jon Warren 4 performance coach


  • 2023 Ironman Hamburg - 9 hours 37 mins, Ironman
    World Championship qualified.

  • 2022 UltraMan UK 2nd place. Bike and run course records.

  • 2021 Ironbourne Long Course Triathlon 10 place, age group winner.

  • 2020 The ETU Duathlon Championships 12th in age group, 35-39.

  • 2019 The Brutal Extreme Double Iron Triathlon 2nd place.

  • 2018 The Brutal Extreme Double Iron Triathlon 3rd place.

  • 2018 The World Duathlon Championships 10th in age group, 35-39.

  • 2018 The Lakesman Long Course Triathlon 10th place.

  • 2018 The Midnight Man Half Distance Triathlon 5th place.

  • 2018 Outlaw Long Course Triathlon Relay 3rd place.

  • 2018 The Maidstone Duathlon 4th place, age group winner.

  • 2017 The Frinton on Sea Half Marathon 1st place.

  • 2016 The Bridge Autumn Duathlon 1st place.


  • Level 2 Diploma British Triathlon Federation Coach

  • Training Peaks Level 1 Certified.

  • UK Anti-Doping (UKAD) Accredited Advisor UK Anti-Doping (UKAD)

  • Clean Coach qualifications.

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Sport for me has been a way to escape, push boundaries and be a part of the most amazing and unique communities. Although sport has always been a large part of my life, swimming at national level, running marathons, open water swimming and taking part in various events such as Hyrox and aquathlons, I had never considered triathlon and the thought of training three sports seemed an unachievable idea. 

However, whilst the world seemed to stop during lockdown 2020, it gave me an opportunity to give it a go; even if I didn’t own a trisuit, and had never ridden a road bike. 

Juggling the disciplines was tough at first and completely overwhelming. This was because I was training three sports separately, instead of training like a triathlete. However, the 4Performance team supported me in finding structure to get me to my first Olympic distance in London. After this event, I fell in love with triathlon and how tough yet rewarding it was. I was also shocked that I had qualified to represent GB in the world aqua-bike championship in Abu Dhabi, where l went on to place 3rd.

Over the past seasons, the drive and the type 2 fun has continued. I have taken on a variety of distances including Challenge London 70.3 and Ironman Barcelona.

As a women in sport who works full time within the education sector, is a part of triathlon communities in London and Essex and trains for multi sport events, I am aware of the barriers and challenges life can have. I am passionate about sport, especially to empower others to strive beyond expectations. Throughout my career I have constantly studied and researched to help develop my own methodologies to ensure that sport becomes a lifestyle rather than a short term plan. I focus on an open humanistic approach to instil confidence and belief, where no question is to small and no goal is too big. 



  • BSc Sport and Exercise Use Science - First Class 

  • Qualified SENCO - Level 7

  • Swimming Teacher and Coach - Level 1/2 

  • England Athletics Teaching Qualification 


  • 2023 - Ironman Barcelona finisher

  • 2023 - Challenge London 70.3, 3rd in AG

  • 2022 - World Triathlon Championships, Aqua Bike, 3rd Place 

  • 2022 - Hyrox finisher 

  • 2021 - Swim Serpentine, 2nd in AG

  • 2021 - Ride 100 finisher

  • 2019 - 110km Ultra finisher 

  • 5 x Marathon finisher 

Mark Billyard


Having discovered triathlon watching the 2000 Sydney Olympics opening triathlon event in Sydney Harbour, and having swum competitively for 15 years, culminating in my highest performance years while at University, I was close to 2012 Olympic trials qualification, when I watched the 2010 edition of Ironman Lanzarote, and decided that it was what I wanted to do as my next challenge… 
So sure enough… I bought my first road bike, and soon started training across all 3 disciplines…

During 2011 I built to my first long distance race, completing 3 x middle distance races, starting with the Cowman British middle-distance championships with my Team MK club mates at the time. In May 2012 I started my first long distance race at Ironman Lanzarote, but unfortunately came off my bike and ended up in hospital, so my first DNF, and not the best start to my long-distance race career. However, it was the 2012 London Olympics that summer, and I watched world class sport with the rest of the world, including the triathlon, and that famous Brownlee 1,3 finish, which was particularly relevant as a fellow Yorkshireman.

Inspired again by the Olympics, I got the bit between my teeth again and entered my new local event at Challenge Henley, completing my first long distance race. 
I consolidated again over winter and went back to Ironman Lanzarote in 2013 despite illness, to finish in my slowest time, but first Ironman, and second long distance finish.  That summer I founded Havering Tri, supported by friends, affiliated to Triathlon London, and went on to grow the club to 150 strong over the next 5 years, fulfilling the chair and head coach roles, and completing my Level 2, Level 2 Head Coach and Level 3 British triathlon coaching qualifications. During this time I started coaching my first athletes on a 1-2-1 basis with online training plans.

Over 12 years, between 2012 and 2022, I completed 20 long distance races and a similar number of middle-distance races. In 2016 I qualified for my first Ironman 70.3 World Championships in Mooloolaba, Australia. I qualified again in 2017, 2018, 2019 and 2022. I posted my fastest ever middle-distance time of 4:26 at the 2016 championships and 3 weeks later posted my fastest ever long-distance time of 9:40 at Ironman Mallorca. A superb 3 weeks. Truly.

In 2018 I raced the 40th Ironman World Championships in Kona, Hawaii, finishing in 10:11 despite carrying an injury. From 2019 onwards I started the Team Orion race team with friends from across the triathlon world and we proceeded to qualify high numbers of athletes for both the Ironman 70.3 and Ironman World Championships. This has been a fun and rewarding focus which provided me a fantastically supportive high-performance community. Having known head coach Jon for many years, now feels like the perfect moment for a new challenge and re-engage directly once again with the wider triathlon community.

Balancing a young family and full-time job, alongside training and competing myself, I understand the pressures involved with work, family and social commitments, and I’ll develop time efficient plans which fit around personal circumstances, focusing on ‘quality over quantity’.



  • 2018 Ironman World Championship, Hawaii 10 hours 11 mins

  • 2016 Ironman Mallorca, Alcudia, Mallorca, 9 hours 40 mins

  • 2016 Ironman 70.3 World Championship, Mooloolaba, Australia, 4 hours 26 mins

  • 2017 ETU Middle Distance Championships 7th in age group, 30-35.

  • 2016/17/18/19/22 Ironman 70.3 World Championships


  • Level 3 HPCP British Triathlon Federation Coach

  • Level 2 Swim England Swimming Coach & Aquatics Teacher



Nick is a experienced endurance and adventure athlete, having competed in running and swimming marathons, ultra marathons, full distance triathlons and bike packing events such as the Silk Road Mountain Race and a ride from London to Istanbul. Nick has gone on to represent GB Age Group in Aqua Bike at European Triathlon Championships during 2022, something I achieved with the consistent training and approach from 4Performance. 

Nick started his endurance sport journey back in 2008 when he ran the Paris marathon as a bucket list achievement of running 26.2 miles. From there Nick just didn’t stop and caught the bug of trying new things and seeing what he could achieve. Before long he'd fallen into triathlon and have competed at all distances since 2010. Nick likes to push his boundaries and see how far he can go with events and challenges with my toughest challenge to date being the Silk Road Mountain Race 2022 through the mountains of Kyrgyzstan. Nick loves the sport of triathlon though and Nick particularly enjoys encouraging new participants as well as being part of the sport from a different side as British Triathlon Technical Official. 

Nick has been coaching triathlon for the last 3 years and have also recently qualified as a swim coach and L2 swim teacher. His passion is getting people into sport and helping them to reach their goals - which Nick achievesf by working with athletes to help them overcome their barriers and find their hidden abilities.

Nick Cull 4 Performance coach


  • 2022 ETU European Multisport Championships Aquabike, 6th in Age Group

  • 2022 Silk Road Mountain Race solo finisher

  • 2018 Outlaw Full Finisher

  • 2017 Unsupported London - Istanbul Ride

  • 5 x Marathon finisher

  • 4 x 70.3 finisher


  • Working towards British Triathlon Level 2

  • British Triathlon Safeguarding

  • L2 Swim Teacher

  • L1 Swim Coach

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Michael Dempster


Sport, in particular individual, endurance sport has been my life since the age of 12. I started off in the rough and tumble world of XC mountain bike racing coming in a very respectable dead last in my very first race – on a Raleigh Activator, wearing a pair of jeans.


Over the following years I managed to improve a little at mountain biking, in the end spending 2 years as Northern Irish champion whilst holding a 100% unbeaten record in all races. I also moved into the world of road racing where I held the same win percentage record as well as racing for a large portion of the year in England with future stars of cycling, including future Tour de France winners and prolific bunch sprinters.


As cross training I decided to join my schools XC running team in the winter and found that I was actually a better runner than a cyclist ending up representing Northern Ireland on multiple occasions.


From there the natural conversation led me to triathlon – even though my swimming was laughably bad, which resulted in some ‘interesting’ race performances – in my first Olympic distance race I managed to come out of the water last, by a long way, come off the bike first, by a good margin, then fade badly in the run. But the bug had bitten.


I have been a personal trainer, sports massage therapist and strength and conditioning coach for more than 15 years and am an Ironman U certified coach.


When you work with me, you can expect sessions that will challenge you, support that will help you to push through sessions when you think you aren’t able to but also a learning experience that will empower you to make sensible decisions when it comes to your own management of yourself and your training.



  • 2021 GB Age Group Team, Duathlon/Middle distance Tri

  • 2020 Outlaw X – 10th – 35-39AG

  • 2020 The Bridge Standard Duathlon – 1st

  • 2020 Ashridge Duathlon – 1st

  • 2007 Ironman Lanzarote – 9th – 20-24AG 

  • 1999 Ireland Triathlon Team – World Olympic Distance Champs

  • 1999 Irish Youth Sprint Distance Champion

  • 1999 Irish Junior Olympic Distance Championship – 2nd



Having played numerous team sports seriously throughout my early years, I got to my mid-30s and wanted to do something different. I started riding to fit in around my life and entered some cycle sportives. A friend at work said he had entered a local triathlon and asked if I would do it with him. I was apprehensive as although I live above a beach and had sea swam in the summer, I had never swum competitively before. My swim amazingly had me near the front of the pack but I was quickly overtaken on the bike and then they poured past me on the run and I came in 156th/252. Once I got my breath back I realised I absolutely loved the triathlon experience. 

After a year of trying to improve by myself, I joined the local Triathlon Club, Torbay Triathlon Club. To get to the next level I needed a coach to guide me to achieve my goals; so, I teamed up with Jon Warren and 4Performance. I could not believe how quickly my graphs were heading upwards under Jon’s coaching. I continued to progress and in 2021 I managed to qualify to represent Great Britain Age Group at the European Championships Sprint Triathlon in Valencia. In 2022 I represented Great Britain Age Group at the Sprint Triathlon at the European Championships in Munich and at the European Multisport Champs Middle Distance Aquabike in Bilbao. These experiences have been life highlights and something that I would love my coached athletes to aspire to achieve.

After 20 years of teaching various sports, in 2022 I thought it would be logical to combine my passion of triathlon and teaching and enrolled on my Level 2 Triathlon Coaching Course. I have coached athletes who have competed in a couple of triathlons and wanted to improve in triathlon to help with their physical and mental wellbeing, through to athletes who have gained qualification to represent Great Britain Age Group Team. Having worked most of my life with secondary school age students, I love embedding good life habits through sport and recognise the part sport can play in physical and mental wellbeing.



  • 2022 ETU European Multisport Championships Aquabike, 13th Place

  • 2022 ETU European Championships Sprint Triathlon, 20th Place

  • 2022 European Championship Sprint Triathlon Qualifier, 3rd in AG

  • 2022 British Sprint Championship, 7th in AG

  • 2022 Plymouth Sprint Triathlon, 3rd Place

  • 2022 Dartmouth Sprint Triathlon, 2nd Place

  • 2021 European Championships Sprint Triathlon, 18th Place

  • 2021 Weymouth Sprint Triathlon, 3rd Place

  • 2019 ETU Aquathlon European Championships, 5th Place

  • 2019 ITU Aquathlon World Championships, 18th Place

  • 2018 ETU Aquathlon European Championships, 18th Place

  • 2018 ITU Aquathlon World Championships, 29th Place


  • Working towards British Triathlon Level 2

  • British Triathlon Safeguarding

  • BSc Sports Science/Physical Education

  • Hockey/Basketball Level 2

  • Football/Cycling/Swimming Level 1

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