Jane Tomlinson has run a series of gruelling races

The 17-hour challenge involves swimming two miles, completing a 112-mile bike ride and running a full marathon.

The 40-year-old mother-of-three, from Rothwell, Leeds, took on the challenge despite a stay in hospital last week.

Mrs Tomlinson completed the event, which started at 7am and ended at 11pm Florida time, in 15 hours 47 minutes.

Sick with nerves

As she left for the first part of the event, Mrs Tomlinson said she felt sick with nerves.

But she now has the satisfaction of going down in the history books as the first terminally-ill person to complete - or even attempt - such a challenge.

To win the event she swam 2.4 miles (3.8km) in the choppy waters of the Gulf of Mexico before mounting her bike for a 112-mile (180km) ride in the blazing midday sun.

She then ran a full 26-mile (40km) night-time marathon.

Mrs Tomlinson has already cycled from Rome to Leeds, completed three London marathons, three London triathlons and two half-Ironman triathlons to raise money for her cancer charities.

She says this will be her last challenge.

'Awfully painful death'

Last week she was admitted to hospital because pain left her unable to walk.

David Hancock, a physiotherapist for Leeds United, helped her to overcome the pain so she could take part in the event.

Her husband Mike, 43, said people should not assume Jane found the events easy.

"Jane's dying an awfully painful death," he said. "Don't be misled by thinking that because she does endurance events, she doesn't suffer.