Athletic Background

Sep began his athletics career at the age of seven at his local club. At age eleven, he came into contact with his current coach, Betty Hofmeijer, initially starting additional hurdle-specific training alongside his regular club sessions. Over the years, this collaboration intensified, eventually leading to a full-time training arrangement. Sep now trains six days per week under her guidance, focusing on long-term development as a 400m hurdler.

In the early youth categories (U14 and U16), Sep was not yet among the top athletes in the Netherlands. This changed significantly from the U18 category onward. In 2022, as a first-year U18 athlete, he represented the Netherlands at the European U18 Championships in Jerusalem, finishing 9th in the 400m hurdles with a time of 52.96. The following year, he narrowly missed the qualification standard for the European U20 Championships by just 0.04 seconds. Despite this setback, he became Dutch U18 champion and ran 52.25, the second-fastest U18 time ever in the Netherlands. achieved with senior-height hurdles.

During the 2024 indoor season, Sep demonstrated strong progression on the flat events. At the Dutch U20 Indoor Championships, he ran a personal best of 49.63 in the 400 meters from lane one, finishing third. He also improved his 200 meters personal best to 23.01. The outdoor season of 2024 presented mental challenges, which prevented him from fully translating his physical form into race performances. Nevertheless, he became Dutch U20 champion in the 400m hurdles in 52.88, placed sixth at the Dutch Senior Championships, and recorded a season’s best of 52.48.

In 2025, Sep continued to experience difficulty expressing his physical potential in competition and therefore began working with a sports psychologist to strengthen his mental approach. In his final opportunity to qualify for the European U20 Championships, he ran a personal best of 52.08. 

In recent years, Sep has regularly raced the 800 meters as part of his training, and he aims to significantly lower his personal best in this event during the indoor season.

Personal records

• 60m hurdles (indoor): 8.18
• 200m: 23.01
• 400m hurdles: 52.08
• 400m (indoor): 49.63
• 800m: 1:56.10
• 800m (indoor): 1:55.79

Strengths

Sep is an exceptionally technical hurdler with the ability to adjust his stride pattern smoothly during races. He can hurdle effectively with both legs, allowing him to alternate steps mid-race without disrupting rhythm. His strong finishing ability enables him to maintain form under fatigue. In addition to his hurdling strengths, he possesses solid endurance, demonstrated by his ability to run a strong 800 meters. Sep has a high training tolerance, remains largely injury-free, and approaches his sport with discipline, motivation, and a strong work ethic.

Areas to Improve

Sep’s primary area for improvement is his maximum speed. To become a faster hurdler, he is focused on improving his flat 400-meter speed through weekly speed development sessions, including technical drills and top-speed work such as flying 30-meter sprints. Mentally, he is working on managing competition nerves and perfectionist tendencies. Through guidance from a sports psychologist, he is learning to separate his self-worth from performance outcomes and to compete with greater freedom and confidence.

Athletic Goals

Sep’s ambition is to become a top-level 400m hurdler in the United States and Europe, competing consistently at major international competitions. His ultimate goal is to qualify for and compete at the Olympic Games, where he aims to perform at his highest level and run fast on the world’s biggest stage.