Ronan Keating and girlfriend Storm Uechtritz work out together - but Storm believes she has slightly more stamina than her other half.
The pair are currently based in London where Ronan is performing in Once: The Musical in the West End until March.
"Ro and I work out together but that's because we do pretty much everything together. We love each other's company and with the busy lifestyle that we have, we capitalise on the time we can spend together," she said.
"We're best friends and that's what best friends do. It also helps that we are pretty much on the same fitness level too, meaning we can work out at the same pace.
"Although I can probably run further than he can, and he can definitely lift more weight than I can," she added.
While Storm (34) comes across as being incredibly confident, she admits she wished she looked different during her younger years.
"My entire childhood I was given unflattering nicknames like 'bones', 'Skeletor' and 'Twiggy' because I was so skinny - I hated it," she revealed.
"All I wanted was boobs and hips like my girlfriends. I come from a tall, lean family and that's just the way we're made.
"I felt really unattractive and unwomanly until my late teens, but now I obviously appreciate those genetics because it means I don't need to worry about putting on too much weight.
"I do, however, worry about keeping the weight on because it's easy for me to drop weight and I don't think the gaunt look is flattering, nor does it promote healthy body image to other women and girls," she added.
The blonde beauty has an enviable figure but reveals her greatest weakness is chocolate.
"I am a proper chocoholic and I even carry around a mini 'chocolate purse' inside my bag with bite sized Crunchies, Cadbury Dairy Mil and Kit Kats. It means I have access to chocolate all day long," she told RSVP magazine.
"Three of the five drawers in our pantry are full of chocolates from all over the world. Ro laughs at me and says I'm like Willie Wonka but I know he secretly loves it and he's just as guilty as me of raiding the stash."
While she didn't make any resolutions for 2015, she did say they wanted to "move to Ireland so we can be closer to the kids".