Treadmill or couch? Workout or poutine? Shin splints or cankles?
Such nagging questions can be especially pesky for women who have shacked up with their personal trainers, as Swedish Crown Princess Victoria did, marrying her former trainer Daniel Westling last month.
The 32-year-old princess, who has battled anorexia, endeared herself to her country by marrying the commoner (but also filed a prenuptial agreement Monday).
Time-crunched, body-obsessed celebrities have long frolicked with their personal trainers - some faring better than others.
Madonna remains on good terms with her ex-boyfriend Carlos Leon, a trainer who fathered her daughter Lourdes. The two have been photographed jogging together and Mr. Leon routinely gives her tips.
"Fitness is one of our conversations. She asks me what the latest workout is," he told British magazine Grazia this week.
Nicole "Snooki" Polizzi of Jersey Shore fame wasn't as blessed. In January, she began dating bodybuilder Emilio Masella, who worked out of Gold's Gym in New Haven, Conn.
"I'm trying to train her, but she's always on the road," the bodybuilder said in March. "I wrote up a diet for her. I'm trying to get her to start dieting and start training. I've been living her life, so I'm trying to get her [to see mine]" (Snooki dumped Mr. Masella the next month, reportedly when he tried to capitalize on her limelight.)
Regular folks say having a trainer as a partner can be uniquely motivating, but also occasionally tense: It's one thing to have a trainer blast your jiggling love handles, but quite another to have one as a lover.
Lorraine Hamilton, a Toronto esthetician, met her trainer husband Kenny Johnston 12 years ago at a nightclub in Scotland, where "most men had their six packs in the fridge, not on them," she remarked.
It was "love at first sight" and Ms. Hamilton routinely gushes about her husband's physique. Still, when the couple works out together on Saturdays, she has her moments.
"He'll say, 'Honey, I've got 10 more for you,' and ... I'm on the couch saying, 'You can do them for the both of us,'" said Ms. Hamilton.
Mr. Johnston takes it in stride: "He just says, 'You'll do them another day.'"
Even with his gentle approach, Ms. Hamilton admits she has issues with her body image. After losing her mother a year ago, she was deeply distraught and fell off the workout wagon. She now feels out of shape ahead of their trip to Mexico.
"You do get a little self-conscious," she said. "If he had a face full of zits, I'd feel I'd failed him as an esthetician. I place that on myself but he doesn't do it to me."
She adds: "It helps to have somebody you trust. He's got such a nice way about him. He's not intimidating."
That allows Ms. Hamilton to hit her husband up for the best techniques, from posture to the mind/muscle connection. "He gave me confidence with free weights," she said.
Thanks to her trainer husband's expertise on everything from power foods to avoiding injuries and intense, efficient workouts, Shannon Furey has gotten fitter with age.
"I was fit but I was never athletic. Being married to my husband, I was influenced," said Ms. Furey, who co-ordinates a smoking cessation program at Toronto's Sunnybrook Health Sciences Centre.
Ms. Furey works out at least five days a week, consulting with her husband Mark Molloy every Saturday after he sees clients at Balance Personal Training, Fitness & Rehabilitation, a boutique gym in the city.
Mr. Molloy appears to show his wife little mercy during their sessions.
"If I'm not working really hard, he tells me, 'You could lift more. You could do more reps. You could run at a faster pace.' Those are the reminders that make me go, 'Oh God.' You can't escape the trainer in him because he's so aware of what I can produce physically with my body."
Last year, Mr. Molloy trained his wife for her first 10k and ran it with her, reminding her to slow her pace and even out her stride. This year she did the Toronto Women's Half Marathon without stopping once.
"I could only run for 12 minutes when I met Mark. Now I can go for hours," she said.
Before their wedding last year, Mr. Molloy also helped tone Ms. Furey's arms - she wore a strapless dress. She was pleased with her wedding photos, but probably would have been less so "if I hadn't had him at my disposal in such an endless way."
Ms. Furey agrees a less confident woman might find the prospect of an in-house trainer daunting.
"Having a husband who's a trainer can definitely affect your body image. If you were someone who struggled with that, it would be challenging because you're always reminded of that."
But on the other hand, Ms. Furey said, an intimate relationship with the trainer can boost self-image by making a woman more realistic about her regimen.
"If a woman has a week where she's really busy and she's not eating very well and hasn't had a chance to exercise, she wonders, 'Oh my god, what damage have I done this week?' I'm able to get a very realistic perspective from my husband who can say, 'Sometimes a rest is a good idea. When you get back at it next week, you'll have more motivation and you'll probably work twice as hard.'"
Diane Anderson, a Surrey, B.C., clinical counsellor who looks at body image issues, has a positive view on the arrangement.
"It may be a terrifically healthy basis for physical intimacy - assuming no ethical boundaries were violated in the trainer-client relationship," says Ms. Anderson. "She has likely developed a very positive body image in her work with him. ...."
And adds: "Healthy body image is very conducive to a healthy sex life, which is an essential part of a healthy loving relationship."
Of course it helps if your trainer husband is a nice guy: Ms. Hamilton's reminds her regularly, "You're fabulous."