A Breton attacker from Brest who became a free agent when Arkéa-B&B Hotels collapsed at the end of 2025, Costiou was snapped up by Groupama-FDJ United on a two-year deal — and promptly justified it with his aggressive style. At his debut Tour in 2025 he animated break after break, most memorably attacking in front of a delirious home crowd at Mûr-de-Bretagne before being caught 12 km out. He then won the Tour du Limousin overall. Aged 23, he is pure raiding stock for the team's stage-hunting plan.
Palmarès
- Tour du Limousin GC winner (2025)
- Tour de France stage 7 combativity award (2025)
- 2nd overall Région Pays de la Loire Tour (2024)
- Mediterranean Games road race silver medal (2022)
Fig. noteHe rescued his career from the ashes of Arkéa-B&B Hotels' demise — and repaid Groupama-FDJ's faith before ever racing for them, winning the 2025 Tour du Limousin without winning a single stage.
The squad
Riding the 2026 Tour with Romain Grégoire, Clément Berthet, Clément Braz Afonso, Lorenzo Germani, Guillaume Martin, Quentin Pacher, Clément Russo — see the full Groupama-FDJ United team page.
Portrait render pending; source reference: Wikimedia Commons, author: Nicola, license: CC BY-SA 4.0.
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