Jurek took a two-year break to write his inspiring story of how a Midwestern backwoods boy became one of America’s supreme ultrarunners. So is he now plotting his comeback, his retirement – or has he burned himself out?

Scott Jurek: 'There are so many great races, which do you make your last?'

Burnout and midlife crisis seem to be occupational hazards for ultrarunners – some might say an obsessive breed by nature – and, in the final chapters of his autobiography, Scott Jurek questions whether he is standing on the edge of a cliff in his own competitive career.

Eat and Run tells the inspirational story of how this Midwestern backwoods boy became probably America's greatest ever ultrarunner: from the mother slowly taken away by multiple sclerosis and the distant, hard-working father; through his adoption of a vegan diet and on to his long years of dominance – seven times victor at the Western States 100, two-times winner of the 135-mile Badwater ultra through Death Valley and triple champion of the 153-mile Spartathlon in Greece.

The epilogue deals with his attempt at a 24-hour race – a particularly masochistic form of ultra where athletes repeat loops of a track as the clock ticks down. He completed 165.7 miles to break the American record.

Since then, Jurek has been busy promoting the book and as a result has barely raced in two years. Meanwhile, Mike Morton smashed his US 24-hour record and Tim Olson knocked almost 20 minutes off his fastest Western States time.

Like many people who enjoyed the book (and the vegan recipes) I wanted to know what happened next. Was he busy plotting his comeback, his retirement or had he burned himself out?

I put the question to Jurek last week during his first trip to Britain. "It's one of those things I battle with," said the Minnesotan, who turns 40 at the end of the month and still looks as lean and energetic as you'd expect an ultrarunner to be. "I know physically I still feel great – and ultramarathoners can definitely still compete with the top guys into their early to mid-40s – but I'm a believer that you have a certain half-life in terms of racing to win, and I'm getting pretty close to the end of that."

Jurek admits his comeback at the Leadville 100-mile trail race this summer "didn't go entirely to plan". He was closing on third place when stomach problems and nausea hit. Where years ago he "used to run through that stuff", this time he lost places and finished eighth. "Overall, I was happy just getting back on the horse and running another 100-miler," he says, "to familiarise myself with what it takes."

When the crowd sees Jurek cross the start line of an ultramarathon with his trademark primal yell they want to see him go on to win – but he tries not to let the pressure get to him. "I was bummed of course. It's a tough thing because everybody wants Scott Jurek to come back and win – but at the same time I've got a pretty healthy relationship with what I've accomplished. Sure, I would love to have won Leadville [he finished second in 2004] and broken the record, or run under 16 hours – but a lot of times I kind of just shrug it off … it's not a big deal, I mean, I have won a lot and I feel very fortunate to have had a great career."

Having told himself he would stop running competitive ultras after 20 years – which works out at around another 18 months – what's on the cards before retirement?

The pinnacle of ultrarunning

Jurek considers the 24-hour race "the pinnacle" of ultrarunning – "there's nothing else like it – mentally it's the most difficult". He's planning an attempt to retake the American record (172.5 miles) from Mike Morton and "the ultimate" would be to beat Yiannis Kouros's world record of 188.6 miles, which the Greek declared in 1997 would stand for centuries.

He doesn't, however, intend to challenge Kouros's 48-hour (294.4 miles) and six-day (645.5 miles) records. "As far as running around a circle for more than 24 hours, total respect for that but it's a little bit too much running for me …"

Jurek might, however, toe the line at Hardrock – probably the toughest 100-miler in the US – in July 2014. He won with a new course record in 2007 and paced Sébastien Chaigneau to a win earlier this year.

Beyond that there are plenty of races around the world he has his eye on: "It's just figuring out which ones are going to fit the best. The hard thing is that there are so many great races, which ones do you make your last couple?"

After stepping off the plane with his wife Jenny last week after a nine-hour flight to London, where he was booked to speak at VegFest, the pair hopped straight on to a train to run a section of the Lakeland 100 UTLD with a small group of Talk Ultra listeners. The Ambleside experience – complete with rain, sun and rainbows – "a good mix of everything" – whetted his appetite.

Jurek describes Richard Askwith's Feet in the Clouds as a trail runner's bible, and the UTLD and an attempt at a Bob Graham (a 65-mile tour of 42 Lake District peaks) – as well as the Paddy Buckley, Ramsay and Wicklow rounds (the Welsh, Scottish and Irish equivalents) – are on the bucket list.

He might have a crack at breaking fastest-known times on some point-to-point trails, with the John Muir path from Mount Whitney to Yosemite, the Pacific Crest Trail and the Sydney to Melbourne "Westfield" route across Australia among the possibles.

There's even the chance of an acting role in the film adaptation of Christopher McDougall's bestselling book Born to Run. Director Peter Sarsgaard had approached him about playing himself and, although a Hollywood power struggle means Sarsgaard is now off the movie, Jurek still hopes he can be involved.

'I'm not running away, I'm running towards'

In Born to Run, McDougall thought Jurek was running away from his problems – but Jurek sees it differently. His childhood toughened him up for the challenge of running ultras. It taught him how to deal with pain and cope with the unexpected – but also provided a healthy escape from a difficult family situation.

"I don't look at it like I'm running away – I'm running towards. Running is a lot better for dealing with a tough situation than, say, turning to drugs. It's a time for you to heal and grow. My childhood helped prepare me for ultramarathons but running gave me this outlet too – I don't think it's healthy to just be caught up in it the whole time and never escape."

When Jurek walks away from competitive sport he intends to keep running ultras for fun – travelling the world on the hunt for adventure, competing with friends in informal mini-races and not afraid of finishing mid-pack.

"I never wanted to get so burned out that I just had to leave the sport," he says. "I want to have a healthy relationship with ultramarathons so I can keep giving back and keep going to events … to feel like this is fun too, that I don't need to win. I want to keep running for the rest of my life."

• Eat and Run: My Unlikely Journey to Ultramarathon Greatness, by Scott Jurek, is published by Bloomsbury, £8.99, paperback.