Two world long-course records fell in men's solo events in 2025, courtesy of Léon Marchand in the 200m medley and Lukas Märtens in the 400m freestyle.

Marchand's mark dated back to American Ryan Lochte 2011 and saw the pace of 200m medley leapfrog the 1:53s and land in the 1:52s inside the pace of the World 200m freestyle record set by American great Mark Spitz for one of his record seven gold medals at the 1972 Olympic Games.

Märtens is second on our list of the top 6 performances of the year only because of the margins by which he took down the 2009 shiny suits mark of Paul Biedermann and got inside the 2002 World textile best of Australian great Ian Thorpe: 0.11 and 0.12sec. In surpassing those standards, Märtens became the first man in history to race below 3:40 over 400m free.

NB: beyond specific categories for short-course (to come), our key picks in our 2025 review focus on long-course swimming because the 50m pool remains the only one in which the very best of almost all the very best available join battle in global competition, and in which pioneering standards are par of the story of the ultimate race-day goal: the Olympic Games.

The Top 6 Performances Of 2025:

The 'ranking' is based on the margin of progress on the clock from what was the prevailing global standard at the time the new mark for set - as well as the all-time ranking of the top swims. For example, The European 200m backstroke record set at Singapore 2025 by Hubert Kós (HUN) and the African 100m backstroke record set by Pieter Coetze (RSA) both rank all-time No5, and would come in at No7 and 8 in our 2025 list after the following six swims ...