Megan Harrington-Johnson doesn't let worry and doubt stop her when she wants to complete a 13km open-water swim. The South African endurance swimmer has swam in shark infested waters, even though she's petrified of them and has had a close shave with a Great White. Megan says she's often the only woman on the team, but thinks it's fear rather than ability that holds other women back from doing what she does. Sweating in the water is an issue and Megan talks about the importance of staying hydrated and eating lots of calories to get through a big swim.

Manu Vilaseca started by running 5km races and now does 160km ultra-marathons. The lengthy courses are rarely on flat terrain, they're normally up and down mountains and the conditions can be unpredictable, but Manu, who's from Brazil, says even when her mind is telling her to stop she knows how to talk herself round and get through. The competitions might be punishing on Manu's body, but she says she loves the feeling of total exhaustion and almost craves the pain she will feel afterwards so she knows she's pushed herself to the limit.

Photo: (L) Megan Harrington-Johnson. Credit: Charl Rorich. Photo: (R) Manuela Vileseca. Credit: Bernardo Rodrigues.