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Meet the Team 

Here are the members who make up the Straightness Training Academy Team.

Marijke de Jong

Founder 

Marijke is the founder of Straightness Training (ST) and The ST Academy. Marijke was born in the Netherlands and shares her life with Marc Marsman, their four horses - Maestro, Romanesque, Prince Elmelund, and Toronto - and their two dogs - Wolfee and Coddi. Together, Marc and Marijke own and operate the company Academia Treinamento de Retidão (ATR), located in Lisbon, Portugal. Today, Marijke is on a mission to make sure YOU have what you need to change your life and that of your horse. 

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Marc Marsman

Chief Executive Officer

The whole ST Community benefits from Marc's designs, portals, systems, automated processes, live sessions, videos, and latest techniques. All this leads to a solid platform where riders can learn, discover, grow, feel inspired, get ideas, find solutions, and become the best ST trainer they can be to create health and happiness for their lovely horses! Marc is passionate about his work for the ST Academy and explores all new trends. He loves the outdoors and finds time to hike and play golf as much as possible. 

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Rosan Veer

Customer Support & Coach Coordinator

Rosan graduated with a BSc in Equine Welfare in 2006 and joined one of Marijke's first ST programs in the Netherlands in 2009. She joined the ST Mastery Program in 2013 before being certified as an ST Instructor in 2015 and as a Grade 2 ST Evaluator in 2019. She also became Customer Service Manager. In 2020, Rosan moved into the role of ST Academy Coach, and Coordinator of ST Academy Coaches in 2021. As of 2022, she also works as a Mentor for Basic ST Instructors and as Coordinator Mentor Instructors. Rosan lives in the Netherlands, with her husband, two sons, and two horses.

Meet the Straightness Training Instructors 

Through our Certification Program, we train and certify ST Instructors from all over the world.


Licensed ST Instructors are a Scholar in The ST Academy and up to date with the highest STandards of teaching ST.

Find the Licensed ST Instructor who is right for you:

ST Instructors »