Lori Hoechlin, 54, from California, a grandmother of three — and mother of actor Tyler Hoechlin (who plays Superman in the TV show Supergirl) — completed her first Everesting attempt in 2015 on none other than Alpe d'Huez. She shares what it was like:

I was in Orion, France, in 2015 with a friend. We were sitting at breakfast, and I said I wanted to Everest - climb 29,062 feet (the height of the famed summit) on the same hill in a single day, by bike. My friend was like, "you should do Alpe d'Huez." We were only nearby for a couple more days, so I didn't even have time to think about it. I guess I'm doing Alpe d'Huez! I headed out the next morning.

Coincidentally, the Tour de France was going through in a couple of days, and all the corners were already lined with fans. I had plenty to see. I went up and came back down. I went up again. People started recognising me. By the sixth time, I was getting applause all the way up. 

I was in the Cycle Huez bike shop at the top of the climb to refuel about nine hours in when I noticed I was starting to get chafing from my bib shorts — they were wearing out! I bought myself another pair of Biemmes right there. It was also a good excuse to get a matching jersey. Then I headed back out.

My GPS watch lasts only 17 hours. All of a sudden, I felt it buzzing and I saw low battery. I was on my eighth and last lap. If my watch died, this wouldn't even count. I picked up the pace. In the Dutch corner, people filled the street, leaving me literally one narrow opening to ride through. They were clapping my back and blowing horns. It was so cool. I finished in 15 hours and 36 minutes, just before midnight. It was 134.1 miles (215.8km).

See what it's like to ride through Alpe d'Huez's Dutch Corner:

And it actually wasn't a huge suffering. To me, it was just an extra-long day of doing something I love. I do double centuries, I've done RAAM. I sometimes think about what I could have done racing bikes if I'd started in my twenties or thirties. I don't regret it, it was worth it to me to invest in my kids for those years. But I do wonder.

Lori's Climbing Tip: "If you want to Everest, pick a steady climb that's not so steep that it's going to chew up your legs. To me, the right balance is somewhere between a 7 and 8% gradient."