Este Haim has revealed she hasn't managed to learn to sleep on the road.
The 27-year-old, who sings in the band Haim with her younger sisters Danielle and Alana, confessed to suffering from chronic insomnia.
"I've tried everything. Everything apart from proper sleeping pills," she admitted.
"I don't want to take those, though, because I know I'll go full Elvis, put on a load of weight and start wearing jumpsuits."
The trio's debut album, Days Are Gone, came out in September, but was originally scheduled to be released sooner.
"Worked out OK, didn't it? There were delays, but when it was finally released it was just about as close to how we wanted it to be as it could've been. We were all so happy," Este said.
"Then we heard the release date we'd chosen was the same day as a whole bunch of other records, one of which being Justin Timberlake's album. That was it, we thought, our chances of being number one were gone, which was fine, but we did it. And we went to number six in the US, which is incredible too."
Alana added: "It was frustrating at the time, but when I look back, I'm not scarred by the long nights and ripping my hair out in the studio. There were times when I thought we should've scrapped everything and started again, but now I think that talk is hilarious. The record's exactly what I always hoped it would be."
Haim begin their UK tour on December 4.