Look at those abs! Guess the celeb flashing her toned tummy!" taunted the US gossip blogger Perez Hilton last week above a picture of a woman photographed from the neck down while wearing Calvin Klein underwear.
According to him, the skinny hourglass figure of the reality TV star Kendall Jenner was recognisable "from a mile away".
To the untrained eye, it was much harder, such is the deluge of celebrity stomachs flooding social media. The recent haul extends across the A-list age range, from the 20s (example headline: "Taylor Swift flaunts abs on girls' night") through the 30s ("Britney Spears' amazing abs and shorts could stop traffic") and into the late 40s ("Nicole Murphy shows off her amazing abs in plunging sports bra as she heads out to lunch with her daughters").
If there's a body part that women are obsessed with, it is the abs. With no limit - from boardroom to beach - as to where you can show it, the middle is having its moment.
Once considered the height of masculinity, gracing only the cover of Men's Health or seen on sports women such as the Olympians Denise Lewis and Jessica Ennis-Hill, the six-pack has become as desirable as cleavage was in the 90s and has usurped the size-zero look of the noughties.
Ab-flaunting is now the summer equivalent of flashing a thigh. They are everywhere, peeping out from crop-tops, displayed as a statement of clean living and workout commitment.
The ripped midriff is this year's erogenous zone and as much as the thought of obtaining one strikes dread into those with softer midsections, we all want give it a try.
Miley Cyrus, rarely seen without a midriff-skimming outfit, is among those who hired Hollywood's ab queen, Mari Winsor, to get hers into shape.
Winsor, who also hones the bodies of Dakota Johnson and Vanessa Williams, says there has been a shift in how women view abs.
"They come in and the first thing they ask is how they get definition," she says. "Above anything else they now want their abs to look better."
Don't we all? What was once an unrealistic goal now seems within our grasp. There's been a huge growth in fitness equipment and workouts designed to accentuate core definition, from circuits with kettlebells and medicine balls to calisthenics (body weight resistance moves) and the likes of CrossFit, from which devotees often emerge with a rock-hard middle.
Sales are soaring of tummy-trimming belts such as Slendertone that deliver a mini workout for your muscles via "electrical muscular stimulation".
They are billed as a secret toning weapon for women who spend too long in the office to devote hours to the gym.
Classes that lure us in with the promise of longer, leaner, stronger-looking abs such as barre, Pilates and yoga, have never been so popular.
It's a good thing, says Winsor, in that it has drawn attention to a body part previously considered a male domain in workout terms.
"Our abdominal muscles are involved in everything we do, every move we make. We can only benefit by improving them and women now realise that."
Belief that we can achieve midriff athleticism is further buoyed by a new wave of personal trainers who promise a six-pack for a fee, then publicise their success on social media.
Among them is the UK-based trainer Joe Wicks, known as the Body Coach. He has 265,000 followers on Instagram, a figure boosted by "success story" images of clients' chiselled midsections shared by them on social media.
Wicks's trademark look is a torso as tautly defined as an Olympian's. Who wouldn't pay £147 for a 90-day plan promising that? He signs up 1,000 new clients a week, all hoping to achieve the dramatic loss of belly fat and the hollowed abs flaunted by his protégées.
"People are beginning to realise what's achievable with their bodies," he says. "Everybody can transform the way they look with the right food and exercise."
Julia Buckley, another online trainer with an impressively hard-worked torso, says abs are undoubtedly the body part most women want to change, relegating bottoms and boobs.
"Having strong abs suggests you have worked for it," she says. "As well as looking good there's a degree of satisfaction in achieving them."
Those signing up to Buckley's 12-week Rebellion plan - mostly women - pay a £50 deposit via Paypal and submit pictures before starting the stomach-crunching regimen. If they succeed in whittling down on her home weights and highintensity training programme, their deposit is refunded.
"A lot of female clients are hugely motivated by that reward," as well as by getting a status symbol stomach, she says.
Is there a short cut to good abs, something we can achieve by the time we need to wear a bikini? Winsor says that "if you eat well and exercise right" there will be visible improvements in four weeks.
However, much of what we thought we knew about getting ripped is wrong: "Just doing 40 or 50 crunches a day isn't going to do it for you. With someone like Miley there's not just a couple of moves involved, it's 30 minutes a day of different exercises like the 100, the double leg stretch and the criss-cross, which are all crucial to sculpting your abs in addition to other regimented exercise."
How you work the abs matters too. It's not all about going hell for leather.
"You have to learn not just to tighten up your tummy muscles but actually to pull your tummy in to your lower back as much as you can," Winsor says.
"Throwing yourself into hardcore circuit classes might get short-term results, but it's unsustainable. Your body can't withstand the demands. You'll get injured."
When celebrities go into what Winsor calls "perfection mode" as they prepare for a film role, attention to the core intensifies.
"They can spend an hour a day dedicated to it. Plus they were born with muscles that respond to training. We shouldn't compare ourselves too closely with their level of leanness."
Yet we have to start somewhere.
Winsor suggests a daily regime of general activity "to get the weight down", cutting calories and possibly wheat intake - "it works for Miley, but it's not strictly something I recommend" - and half an hour of Pilates-style exercises and as many different ab moves as you can muster.
Failing that it's navel in and shoulders back. Whatever else you do this summer, don't slouch.
1 Don't go hungry: Drastically reducing calories burns fat at first, but eventually your body slows down to conserve energy and you actually gain body fat around your middle.
2 Don't focus solely on the abs: squats and lunges are among the best exercises for a lean middle. Because they are great calorie-burners, they reduce all-over body fat to reveal muscles beneath.
3 Do HIIT: Most experts agree that high-intensity interval training (HIIT) should be the groundwork for any ab-defining programme. This involves short bursts (try 20 seconds) of flat-out activity with exercises such as burpees, hill sprints or Jump squats followed by a brief rest (40 seconds) for only 5-20 minutes in total.
4 Avoid endless crunches: They work only the front of your abdominal muscles and neglect the sides. A variety of ab exercises is crucial for the super-toned look.
5 Vary your ab moves: Pilates is a good starting point, but include everything from the side plank and Superman moves to the 100 and leg raise. Boredom is an enemy of the abs, so be inventive.
Joe Wicks, thebodycoach.co.uk; Julia Buckley, Juliabuckley.co.uk; Mari Winsor, winsorfit.com