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Mark Threlfall


Mark Threlfall is an ex-professional triathlete having been part of the British Triathlon team for many years, following a successful early career as a swimmer. Mark started his triathlon career in 2007 taking part in short distance triathlons before moving up to longer distance triathlons in 2012. Mark has had a number of career highlights and now offers triathlon and swimming coaching, alongside presenting on the Global Triathlon Network.

Mark Threlfall Triathlete In A Cycle Road Race

"Forth has allowed me to regularly and easily keep a check of my iron levels, which is something I was struggling to do before without trips to the hospital. This means I can stop levels from becoming dangerously high, which is not only bad for my performance but also my health. It also means I can plan when to give blood to bring my levels back down, which obviously also has a negative effect on performance. Being able to plan these in for the off-season and away from racing was vital for me, and continues to be with the new challenges that I am undertaking with GTN."

Mark started out his career at the age of 11 when he started to compete nationally as a swimmer, competing at a national level and podiuming at the national championships, before making the transition to triathlon around 2007.

Mark always had his sights set on representing Great Britain at the Olympics and was selected for the World Class Programme for Great Britain in 2007, from there he competed in both World and European Championship events. During this time Mark won silver at the European Duathlon Championships in 2007, and bronze at the ITU Cross Triathlon World Championships.  Mark progressed onto middle distance triathlons in 2012, where he was placed 3rd at Ironman 70.3 UK in his first year as a professional.

In 2012 Mark stepped up to longer distance triathlons, having great success, all this while he was battling with turbulent health.  Then in 2015/16 Mark found out he had Haemochromatosis, which is a hereditary condition where iron levels gradually build up in the body over time.  This obviously had an adverse effect on Mark’s health.  This is where Forth Edge came in, Mark has been able to monitor his iron levels and calculate when he has to give blood to bring his iron levels down without affecting his racing schedule.

You can find Mark on the Global Triathlon Network YouTube channel.

Marks's Favourites

Q. What is your Pre-competition meal?

A. You can't go wrong with Pizza or a Spag Bol.

Q. What is your go-to treat?

A. Those Crimbles' chocolate coated macarons.

Q. Favourite music for motivation?

A. Some cheesy electro.

Q. What Superhero would you be?

A. Given my iron levels and triathlon, I would have to be Ironman.

Career Highlights

2017 Outlaw Half Champion, and record holder
2017 Ironman 70.3 South Africa
2012 Ironman 70.3 UK
2011 Extremadura ITU Cross Triathlon World Championships U23
2010 British Standard Distance Triathlon Champion
2007 Silver at the European Duathlon Championships
2007 Silver at the European Duathlon Championships
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