Kevin Sinfield is embracing a new challenge as he sets off on his bid to run seven marathons in seven days in support of former team-mate Rob Burrow.
The Leeds Rhinos director of rugby is aiming to raise £77,777 in support of both Burrow, who he played alongside at Leeds in Super League for 15 seasons, and the Motor Neurone Disease Association following the 38-year-old's diagnosis with the disease 12 months ago.
The number seven features prominently due to it being the one most associated with Burrow throughout his playing career and Sinfield has seized the opportunity to push himself in support of someone who is a close friend as well as a former team-mate.
"You miss challenges when you finish playing and I've been fortunate enough to run a few marathons for charity, but this is obviously very close to all of us," Sinfield told Sky Sports News.
"This means we get keep Rob in the forefront of everyone's minds, especially with it being in the run-up to Christmas. We hope to raise lots of money and raise plenty of awareness.
"Any way we can make sure he's at the forefront of people's minds, we will. We've all got the No. 7 on our backs and he is so overwhelmed by the support he's had.
"Hopefully he'll be smiling when he sees us setting off in the freezing cold."
Sinfield set off on the first marathon on Tuesday morning and completed it in a time of 3hr 40min, with his aim being to complete the 26 miles for each of the seven days inside the four-hour mark.
The former Great Britain and England international's effort is just one of a number of fundraisers ex-team-mates, and those from the wider rugby league and sporting worlds have embarked on in support of Burrow.
Sinfield has already gained a taste of what to expect during the next week, but knows the struggles will be worth it to help both Burrow and the MNDA.
"I'm prepared for that and I think I know what is coming," Sinfield said. "I did three in three at the end of October just to get a taste and got sent to some pretty dark places on that one.
"But if it's not going to push us and test us then it's not really a challenge, so we'll throw everything at it and do our absolute best. We're very proud to be wearing the MNDA vest and hopefully we'll do Rob proud.
"I had a lovely message off him and the kids, which is exactly why we're here. He's certainly facing the biggest challenge of his life and for us to come out and do a bit of running before Christmas is really good."