Por primera vez, el Campeonato Mundial Ironman 70.3 se llevará a cabo en Lahti, Finlandia, los días 26 y 27 de agosto.
En la lista de salida los dos campeones de 70.3 del año pasado Taylor Knibb (EE. UU.) y Kristian Blummenfelt (NOR) al igual que una larga llista de auténticos favoritos, la cinco veces campeón mundial de 70.3 Daniel Ryf (SUI), el campeón en Kona Gustav Iden (NOR), Paula Findlay (CAN) y Tamara Jewett (CAN), así como Sam Long (EE. UU.) y Lionel Sanders (CAN).
Entre las bazas españolas tenemos a Gonzalo Fuentes, Jordi Montraveta y Anna Noguera que pelearan para estar lo más arriba posible en este Campeonato Mundial Ironman 70.3
Start List Femenina
| BIB | NOMBRE | PAÍS |
| 1 | Taylor Knibb | USA |
| 2 | Paula Findlay | CAN |
| 3 | Emma Pallant-Browne | GBR |
| 4 | Daniela Ryf | CHE |
| 6 | Holly Lawrence | GBR |
| 8 | Jackie Hering | USA |
| 9 | Laura Philipp | DEU |
| 11 | Tamara Jewett | CAN |
| 12 | Anne Reischmann | DEU |
| 15 | Kat Matthews | GBR |
| 16 | Marjolaine Pierre | FRA |
| 18 | Ellie Salthouse | AUS |
| 19 | Danielle Lewis | USA |
| 20 | Rach McBride | CAN |
| 22 | Caroline Pohle | DEU |
| 23 | Pamella Oliveira | BRA |
| 24 | Anna Bergsten | SWE |
| 25 | Ai Ueda | JPN |
| 26 | Olivia Mitchell | IRL |
| 28 | Charlene Clavel | FRA |
| 29 | Lucy Buckingham | GBR |
| 30 | India Lee | GBR |
| 31 | Maja Stage Nielsen | DNK |
| 33 | Imogen Simmonds | CHE |
| 34 | Almelia Watkinson | NZL |
| 35 | Girgia Priarone | ITA |
| 38 | Laura Jansen | DEU |
| 39 | Hannah Berry | NZL |
| 40 | Emilie Morier | FRA |
| 41 | Daniela Kleiser | DEU |
| 42 | Alexia Bailly | FRA |
| 43 | Anna Noguera | ESP |
| 44 | Lottie Lucas | ARE |
| 45 | Kaidi Kivoioja | EST |
| 46 | Kate Curran | GBR |
| 47 | Tiina Pohjalainen | FIN |
| 48 | Lisa Gerb | DEU |
| 49 | Justine Guerard | FRA |
| 50 | Sarah Bishop | USA |
| 51 | Julie Iemmolo | FRA |
| 52 | Eloise du Luarte | FRA |
| 53 | Laura Addie | GBR |
| 54 | Nikita Paskiewiez | FRA |
| 55 | Brittany Higgins | USA |
| 56 | Bruna Stolf | BRA |
| 57 | Amy Cymerman | USA |
Start List masculina
| BIB | NOMBRE | PAÍS |
| 1 | Kristian Blummenfelt | NOR |
| 2 | Ben Kanute | USA |
| 3 | Gustav Iden | NOR |
| 4 | Frederic Funk | DEU |
| 5 | Miki Taagholt | DNK |
| 6 | Jackson Laundry | CAN |
| 7 | Thor Bendix Madsen | DNK |
| 8 | Sam Long | USA |
| 9 | Jason West | USA |
| 11 | Pierre Le Corre | FRA |
| 14 | Justus Nieschlag | DEU |
| 15 | Jordi Montraveta Moya | ESP |
| 17 | Lionel Sanders | CAN |
| 18 | Steven McKenna | AUS |
| 19 | James Teagle | GBR |
| 20 | Menno Koolhaas | NLD |
| 21 | Filipe Azevedo | PRT |
| 23 | Kacper Stepniak | POL |
| 24 | Mike Phillips | NZL |
| 26 | Rico Bogen | DEU |
| 27 | Franz Loeschke | DEU |
| 29 | Dylan Magnien | FRA |
| 20 | Adriano Engelhardt | CHE |
| 31 | Jack Moody | NZL |
| 32 | Nicolas Mann | DEU |
| 33 | Mathis Margirier | FRA |
| 34 | Matt Hanson | USA |
| 35 | Bart Aernouts | BEL |
| 36 | Matt Trautman | ZAF |
| 37 | Jan Stratmann | DEU |
| 38 | Youri Keulen | NLD |
| 39 | Tomas Rodriguez Hernandez | MEX |
| 40 | Alessandro Fabian | ITA |
| 41 | Jonas Hoffmann | DEU |
| 42 | Ognjen Stojanovic | SRB |
| 43 | Andrea Salvisberg | CHE |
| 44 | Marc Dubrick | USA |
| 45 | Mitch Kibby | AUS |
| 46 | Martin Ullola | CHL |
| 48 | Antony Costes | FRA |
| 49 | Charine Quin | AUS |
| 50 | Dylan Gillespie | USA |
| 51 | Igor Amorelli | BRA |
| 53 | Jack Sosinski | AUS |
| 54 | Joshua Lewis | GGY |
| 55 | Robbie Deckard | USA |
| 56 | Jorgen Gunderson | NOR |
| 57 | Gonzalo Fuentes | ESP |
| 58 | Maximilian Sperl | DEU |
| 60 | Nick Thompson | AUS |
| 61 | Kye Wylde | AUS |
| 63 | George Goodwin | GBR |
| 64 | Richard Varga | SVK |
| 65 | Benjamin Zorgnotti | PYF |
