Anna Rutherford, 38, started the coast-to-coast route from Portpatrick in Dumfries and Galloway on Thursday morning at 5am and finished in Cockburnspath in the east of Scotland on Saturday evening.
The run took her 62 hours and 34 minutes during which she only slept for about an hour and a half in total in short 11 minute stints.
The Ultra Great Britain club runner, who works as a lawyer in Edinburgh, said she wanted to embark on the challenge to get fit after giving birth to her second child just nine months ago.
Speaking to The Scotsman, the mum-of-two said the race was one of the hardest challenges she has ever done.
"I felt broken and exhausted at the end but also the whole thing was just incredibly rewarding,” said Anna, who lives in the Peebles with her husband Neil, two-year-old son Kit and baby daughter Ella.
"It’s up there with how I felt after childbirth.
"I only gave birth to Ella nine months ago and there are so many parallels with having a baby. You’re exhausted, you don’t know what’s going on and you’re pushing your body to the extremes, but it feels amazing.”
Anna said she avoided listening music until the final push when she knew she needed it most – S Club 7 and Queen were some of the artists that kept her going.
"I am 38-years-old but I confess Reach For The Stars was one of the songs I really needed.”
Despite burning about 25,000 calories, Anna only consumed around 2,000 during the run and she was sick several times.
But one tip she swears by that kept her going was eating stock cubes.
"There were plenty of food supplies but I just couldn’t eat,” she said.
"My friend Lucy Colquhoun recommended having a bag of crumbled stock cubes to dab my finger in when feeling weak and it worked. It settled my stomach and helped restore my electrolytes and encouraged me to drink water.”
Anna said one of the hardest parts about the challenge was not seeing her children – it was the longest she had ever been without them.
"I’d never had a night without them and it made me so emotional.
"Neil met me at two points on the run with the children which helped so much. Whenever I was feeling low and exhausted I asked the team supporting me to get Neil to send pictures of Ella and Kit to show me.”
She added: “It meant a lot to finish, and to break the record because if I – a normal mum with two kids – can do something like that, then anyone can.
"And I was determined to show Ella and Kit that having dreams and fulfilling them is possible.”
Anna had a team of friends to support her along the way, including Jack Scott who holds the men's record with a time of 55 hours and 42 minutes and who ran with her on one of the sections.
She added: "The friends and family supporting me really did all the work – I just had to keep running, walking and crawling until the finish line.”