The 36-year-old played five Tests for the Lions between 1997 and 2005, touring three times with Britain and Ireland's elite.
His injury-enforced absence from the latter stages of the 2001 tour of Australia and most of the Test series in New Zealand four years later are still seen as central reasons behind the Lions' failure to beat the Wallabies and All Blacks.
Hill faced numerous challenges throughout his 15-year career at the highest level, fighting back from serious injuries to cement his reputation as one of the game's toughest players.
But Hill has a new objective now he is no longer involved as a player.
The World Cup winner is taking part in the Great British Bike Ride (GBBR) and will be cycling from Lands End to Twickenham.
The four-day ride aims to raise £1.5 million and will feature nightly stops at local rugby clubs in Tavistock, Yeovil and Winchester before finishing at English Rugby's Headquarters on Saturday, September 4 - the day of the annual Guinness Premiership Double Header.
"Since I retired from rugby in 2008 I have continued working with Saracens and, where possible, I have been seeking opportunities to give back to the game," said Hill, who was a World Cup winner seven years ago.
"I was looking for a new challenge after kayaking in Norway last summer with Saracens and the GBBR seemed perfect.
"I probably needed a challenge to get back into some sort of shape.
"Having tipped the scales at 18st 3lb it was probably time to redress the balance and to be able to raise money was a big incentive for me.
"The hard work of training for such a challenge has begun and I've already shifted about a stone in weight! Needless to say, there are a lot more hard miles ahead!"
Hill will be raising money for the RFU Injured Players Foundation, the RPA Benevolent Fund, Help for Heroes and the Saracens Sports Foundation, charities he feels particularly close to, especially having himself undergone a total knee replacement in June last year.
"The charities that GBBR are supporting are fantastic causes and I truly believe in the work that they do," added Hill.
"I was lucky enough to have a long and successful career but I also had my fair share of injuries over the years, with various problems with my back, neck, nose, shoulder and groin, not to mention the significant problems I have had with my knee.
"I've had a total knee replacement this year. That's not a reconstruction, but a whole replacement. Usually these operations are done at about the age of 60, not at the age of 36!
"The new knee has a life expectancy of 10-15 years so I won't be doing any running on it but, fortunately, cycling is fine as it keeps the majority of my weight off the knee.
"Personally, I feel that getting on a bike for four days of cycling is the least we can do to help these fantastic charities that do so much for both our armed services and for our sports men and women. I'm looking forward to doing my bit."