Despite being in their 50s, runners Tony Wimbush and Colin Brooke, pictured, are in training for one of the toughest long-distance endurance events in the world.

They are preparing to negotiate the 220-mile John Muir Trail in the mountains of California.

The two Bradford men - both 52 - hope to complete the route, which includes climbing 13,000ft Mount Whitney and avoiding hungry bears, in only 12 days.

Joining them are two friends Paul Frechette, 53, and Dr Rod Sutcliffe, 51, both from Halifax.

For the first seven days they will have to carry all their provisions on their backs, purify their drinking water and tolerate high altitude as they negotiate 11,000 feet passes.

"It is one of the toughest simply because of the time spent in carrying provisions, the terrain and the need to filter water as you go along," said Colin, from Northowram.

"A lot of the time will be spent at altitude and for the first seven days we will be carrying 30lb packs."

After about seven days they reach a lakeside location - still miles from civilisation - where they can re-stock with provisions.

Tony and Colin are veterans of a number of long distance challenges, most of which they run. They completed the Corsican high level trail - one of the toughest routes in Europe - in just six days. Most people take two to three weeks.

But the demands of this trail will keep them down to a walking pace.

Even so, they expect to average 20 to 25 miles a day along the route from Mount Whitney to Yosemite.

As part of their training programme they have become the first athletes to run the 45-mile Bradford Millennium Way, in a time of 11 hours 12 minutes.

The route was created by a group of countryside service volunteers to commemorate the Millennium.

"We weren't setting a record. It could be done quicker than that. We did it without any back-up and had to find food and drink as we ran round.

"And we had to carry the Millennium Way booklet to keep to the route," said Tony, of Bolton Road, Bradford.

They recently conquered the UK Three Peaks of Ben Nevis, Scafell Pike and Snowdon and the Yorkshire Dales Three Peaks of Whernside, Pen-y-ghent and Ingleborough in just 22 hours 30 minutes as their Millennium challenge.

And before embarking on their trip to California, they plan to compete in the 100 mile Lakeland walk - they will mostly run it - at Spring Bank.

l St Bede's Athletic Club is holding a relay race along the Bradford Millennium Way on Sunday June 30.