Considered the most exciting talent to move up in distance since Alistair Brownlee, Marten Van Riel signing on with Bahrain Victorious was a statement of intent to dominate at the world championship level.

In 2025 after securing his first Ironman World Championship berth with a silver medal at the Ironman African Championship, he went on to win Ironman 70.3 Nice in June — a strong prelude to taking on the full distance in Nice that September. The Belgian delivered an impressive world championship debut, finishing just off the podium in fourth place. He capped the year with a bronze medal at the last race of the season in Doha at the T100 Grand Final.

After his third Olympic Games where he finished 4th in Tokyo, he took the silver medal at the 2021 World Triathlon Championship Series. He then began focusing on the middle distance, having won his 70.3 debut in Xiamen in 2019 and since going undefeated in Ironman 70.3 racing.

Signed to a T100 Tour contract in 2024, he won three out of the four events he raced to become its inaugural champion, before racing his debut Ironman in Cozumel where he finished 7th to end the year ranked PTO World #1.