If Baywatch was famous for a single thing, it'd have to be for how ridiculously in shape the cast were.
Which means, when they decided to film a Baywatch remake, the cast were going to have to work their butts off to get the same killer bodies seen in the hit beach series.
Patrick Murphy, 'trainer to the stars', worked with actors Zac Efron and Alexandra Daddario, and has since revealed the gruelling schedule he put them on to get in shape for filming.
"Patrick's training was confusing at first ... I just thought I was showing up to lift weights and get a deeper six pack (which is hard enough already)," Zac wrote in a statement to E! News.
"But rather than the typical bodybuilding type of movements I had become accustomed to, Patrick pushed me to my 'functional' limits with a very multifaceted style: strength, explosiveness, fast paced, calculated, diverse and gut-wrenching workouts. It was fun ... you never know what he's going to throw at you the next day."
But, just as Efron is known for his enthusiasm off the camera, he was also incredibly enthusiastic about getting in shape.
In fact, the actor was so enthusiastic that, as soon as he'd finished his hour session with Murphy, he'd do some professional lifeguard training and, because that still wasn't enough, he'd go for a 32km bike ride.
But, just because Efron was incredibly keen on his fitness regimen, didn't mean the actors loved everything Murphy threw at them.
One circuit specifically made the actors do something along the lines of "20 alternating jump lunges in one place, 20 jump squats, 60 mountain climbers, power push-ups, followed by a run up five flights of stairs, then one-leg squat hops using a TRX rope," Murphy explained.
Then, when they'd survived that circuit, Murphy revealed he'd let them rest for a minute, and then make them do it two more times.
And, just like Efron, a new Women's Healthprofile on his co-star Alexandra Daddario reveals she wasn't spared either.
The actress, who was "literally in a bikini the entire day", told the publication she even wore a swimsuit when she auditioned with Efron.
Daddario trained four to five times a week with the celebrity trainer who trained her so she was able to "run wobble-free on the sand", even in slo-mo if she so desired.
Murphy uploaded a photo last year of Daddario, praising her for her motivation while they were filming.
"When a bathing suit is your wardrobe for a major motion picture, #Baywatch, let's just say motivation from me, the trainer, isn't necessary.
Very proud of all the hard work @alexannadaddario has put in for movie prep ... Made my job easy," he captioned the photo.
Baywatch hits cinemas on June 1.