A FATHER and son will be running seven marathons in six days to raise money for cancer research.

Gary and Matthew Cust are training for the world's toughest running challenge, the Marathon des Sables, also known as the 'toughest footrace on earth'.

Matthew’s partner Adele was diagnosed with cancer as a teenager and recently received the ‘all-clear’.

Gary said: “It’s shocking how many people you know whose lives have been devastated by cancer.

“Wonderfully, fewer people are dying because of research.”

The pair will need to run seven marathons, in excess of 170 miles, across six days in the Sahara Desert through sweltering 50 degrees Celsius heat, carrying everything they need to survive for the week.

“I know we can complete the Marathon des Sables," added Gary.

"It’s just one foot in front of the other, and I can always find one more step.

“No matter what, we will be at the finish line.

“It will be horribly brutal, but when we get our medals I’ll know that it was all worth it.

“It will be the best thing I’ve ever done.”

Gary has always been a runner, completing over fifty marathons whilst in his 40s, and now burns more than 3000 calories during daily training.

His son Matthew, 27, is a research scientist and is training for the six day desert challenge alongside his career.

Gary said: “Matt finds it really hard.

“He starts work at eight and will be home by 4.30 so we go out running for two hours after he finishes work.

“Matt has youth on his side so it's all about reaching peak condition,” he added.

On January 14 the father and son plan to run a marathon on a treadmill inside Broad Street Mall to help raise the £20,000 they have promised to Yorkshire Cancer Research.

Gary, a retired lawyer, concluded: “I'm running everyday and it's hard to find time to raise money and gather support so this event is especially important. Running inside and out of the cold will be a nice change.

“There's the potential to raise lots of money but it depends on how generous people are feeling after Christmas.”