Everyone remembers the first time they saw the trailer for the 2017 Baywatch reboot. There was the slow-motion running, the classic red shorts, and then there was Zac Efron. He didn't just look fit. He looked like he had been sculpted out of granite by a team of Renaissance masters who were obsessed with low body fat.
He was shredded. Like, "every-vein-on-his-stomach-is-visible" shredded.
But behind those iconic Zac Efron Baywatch abs was a reality that wasn't exactly a beach party. While the world was busy googling his workout routine, Efron was privately hitting a wall that almost broke him. He has since been very vocal about how that specific transformation was one of the darkest periods of his life. Honestly, if you're trying to replicate that look, you might want to hear the full story first.
The 5% Body Fat Myth and the Reality of Lasix
To get that "computer-generated" look, Zac Efron worked with trainer Patrick Murphy. They weren't just lifting weights; they were executing a scientific teardown of the human body. Efron eventually reached about 5% body fat. For context, most professional athletes don't even stay that lean because it’s physically exhausting.
He wasn't just eating clean. He was suffering.
Efron later revealed to Men's Health that the look was essentially "fake." To get his skin that paper-thin, he had to use powerful diuretics like Lasix. These are "water pills" that flush every bit of fluid out of your system so your muscles pop against your skin. It makes for a great movie poster, but it wreaks havoc on your internal organs.
You’ve probably seen the pictures of him standing next to Dwayne "The Rock" Johnson. Even The Rock, who is a literal mountain of a man, reportedly found Efron’s dedication to the grind intense. But that level of dehydration isn't a fitness goal; it's a health hazard.
A Typical Day in the Baywatch "Hell" Routine
If you want to know what it actually took to be Matt Brody, the schedule was basically a form of torture.
- 4:00 AM Wakeups: Even if filming went until midnight, Zac was up at 4:00 AM to train.
- Zero Carbs or Sugar: He tweeted back in 2016 about doing nine days of absolutely zero carbs and sugar. Only organic, grass-fed protein and leafy greens.
- The Workout Split: It was a 3-day split (Back/Biceps, Legs, Chest/Shoulders) repeated with almost no rest days.
- Supersets: Everything was done in pairs with zero rest between moves to keep the heart rate at a fat-burning max.
It sounds impressive until you realize he was doing this while 100% sleep-deprived. He started developing insomnia. He fell into a "pretty bad depression." His body wasn't just tired; it was shutting down.
Why he wouldn't do it again
Looking back, Efron has called the look "stupid" and "unattainable." He told Sean Evans on Hot Ones that he realized once the movie was done that he never wanted to be in that shape again. He’d much rather have an extra 2% to 3% body fat and actually be able to think clearly.
The Physical Toll Nobody Saw
The Zac Efron Baywatch transformation wasn't the only time he pushed himself, but it was the one that left the most scars. During that general era of his life, he suffered a string of brutal injuries:
- Torn ACL
- Dislocated shoulder
- Broken wrist
- Blown-out back
- Shattered jaw (though this was a home accident, the recovery was complicated by his physical state)
When your body is that depleted, it becomes brittle. You aren't "strong" in the functional sense; you’re just a fragile shell that looks good in a specific light.
How Zac Efron Trains in 2026
Fast forward to today, and Zac’s vibe is completely different. He’s moved away from the "shredded at all costs" mentality and toward longevity. After his role in The Iron Claw—where he got massive but kept a much healthier level of body fat—his focus shifted to feeling good.
He's now a "foam-rolling fanatic."
His routine nowadays involves ice baths, which he calls his favorite part of the day. He uses them to "conquer something deep within" himself. He also sticks to intermittent fasting, which he found worked better for his digestion than the strictly vegan diet he tried for a while. He still eats clean—lots of elk, chicken, and sweet potatoes—but he isn't weighing every gram of broccoli anymore.
What You Can Actually Learn from the Baywatch Era
If you're looking at those old photos of Zac Efron and feeling like you're failing your fitness goals, stop. Even Zac Efron couldn't keep the Zac Efron body. It was a snapshot in time achieved through medical-grade diuretics and a lack of sleep that caused clinical depression.
The real takeaway?
- Avoid Diuretics: Unless a doctor prescribes them for a heart condition, stay away. Dehydrating yourself for "definition" is a quick way to kidney issues.
- Prioritize Sleep: Muscle grows while you sleep, not while you're doing curls at 4:30 AM on three hours of rest.
- Functional Over Aesthetic: It’s better to have a "four-pack" and be able to jump, run, and lift without breaking a bone than to have an "eight-pack" and be bedridden with injuries.
Zac Efron is still in incredible shape, but he’s doing it with a lot more grace and a lot more carbs these days. He’s proof that you can be a Hollywood leading man without sacrificing your mental health at the altar of 5% body fat.
If you're planning your next fitness phase, focus on mobility and recovery. Use foam rollers, try the occasional cold plunge if you’re brave enough, and remember that even the guys on the posters don't actually look like the guys on the posters most of the year.
Next Steps for Your Fitness Journey:
If you want to build an athletic physique without the "Baywatch burnout," focus on a sustainable 4-day strength split and prioritize a high-protein, whole-food diet that includes complex carbohydrates. Replace extreme dehydration tactics with consistent hydration and at least seven hours of sleep to ensure your nervous system stays as healthy as your muscles.
