The 29-year-old, from Newington, is now more than halfway through his bid to run 100 marathons in 85 days from John O'Groats to the Moroccan Sahara in aid of charity and has no intention of taking a day off, especially as he has to get back home for his wedding on February 19.
Andrew is spending the Christmas period just outside the city of Soria in central Spain and was completing another 32-mile run in aid of the Yamaa Trust, which aims to alleviate poverty in the Gobi Desert.
He said: "Once I've completed my stint I'll retire to the camper van accompanying me on the run and now being driven by my fiancee, Jennie."
Andrew became concerned by the plight of many Mongolians while undertaking a charity project in the country.
He said: "I've absolute no regrets about undertaking the run other than the fact I miss my regular intakes of Irn Bru, and getting hold of the football results from home can be difficult at times.
"So far I've raised 36,000 of the 100,000 I've challenged myself to achieve.
"The worst aspect has been the harsh winter conditions but the highlight has been the reaction of people I've met along the way, although I could do without trucks splashing me with slush so often.
"I'm loving the variety of scenery, although for two weeks this has mostly been snow. I'm having to eat enough calories for two-and-a-half men and am making full use of local delicacies, having eaten more than 20 pain au chocolates in one week while in France."
The 2685-mile expedition, which started in November, is being filmed for a one-hour Adventure Show special on the BBC.
Over the course of his journey, Andrew has been joined by more than 500 runners at various stages.
He said: "When I was heading through Scotland a group of refuse collectors even decided to run with me for a few miles. The physical challenge has been relentlessly difficult.
"I haven't been injury free and have had plenty problems with my Achilles tendons and iliotibial band, but both are common running injuries and are improving.
"On January 11, I'm due to cross into Africa and with a scheduled finishing date of January 31 that will feel like I'm on the final leg of a journey I'd definitely tackle again, although probably over a different route for a bit of a change."
For further details, see www.scotland2sahara.com.