But imagine taking on the 855-mile challenge just four weeks after being given the all-clear from swine flu, a chest infection and knee surgery.

That is the mammoth task Helen White has set herself to raise vital cash for charity.

The 43-year-old tennis fanatic also hopes to complete the ride with dad Graham and six other cyclists in memory of former instructor Andy Andrews.

Mrs White, from Testcombe Road, Alverstoke, Gosport, who is a committee member at Lee-on-the-Solent Tennis Club, said: 'I planned to do this ages ago but I had keyhole surgery to repair the cartilage in my right knee which set me back.

'Then I had swine flu and a chest infection so I've only really been able to train for about four weeks, but I'm determined to do it.

'Cycling from Land's End to John O'Groats was something Andy always wanted to do, but sadly he was never able to.

'It was thanks to his coaching that I was selected for the Hampshire County tennis team when I was younger.

'It would have been his 95th birthday this year and I thought this would be an ideal way to celebrate it.'

Mrs White hopes to raise more than £1,000 for Lee-on-the-Solent Tennis Club and the Parkinson's Disease Society by completing the challenge in just 11 days.

She added: 'I know it won't be easy but I just wanted to give something back and do it in Andy's memory.

'He did so much to help other people when he was alive.

'The Parkinson's Disease Society and the tennis club were the obvious places to raise money for.

'Andy's wife Joyce died from Parkinson's and it seemed right to raise money for the club he loved.'

The team will start their adventure on Wednesday.

To sponsor Helen e-mail woo.white@ntlworld.com or call (023) 9255 0381.