Gabrielle Union, Miranda Kerr, Vanessa Hudgens, More Share Health Tips That Will Help You Get Fit Fast

Hollywood's hottest stars are notorious for being able to get fit fast. Whether training for a physical role on screen or snapping back a post baby body, celebs know how to pull out all the stops to make sure their bodies are tight and right with the clock ticking.

So how do they tone up in such a short period of time? OK! is revealing the go-to, crunch-time healthy habits Hollywood's famous faces use to look and feel their best.

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Scroll down to get the inside scoop on celebrity-approved health and fitness tips that you can practice now!

When Beyoncé wanted to get in shape for her show-stopping 2018 Coachella performance following the birth of her twins, she stuck to trainer Marco Borges' 22-day plant-based eating plan for 44 days. "In order for me to meet my goals, I'm limiting myself to no bread, no carbs, no sugar, no dairy, no meat, no fish, no alcohol," the singer, 39, explained. The result? She dropped pounds and gained serious stamina. "When you're eating plant-based," said Borges, "you will definitely have more energy."

It's the oldest trick in the book, but getting your daily fill of water aids in flushing out toxins, speeding up the metabolism and keeping hunger in check. Just ask ageless beauty Gabrielle Union, 48, who drinks a gallon a day! "I started [in my mid-30s]," she's said. "It changed everything from weight maintenance to hair, skin, nails and digestion." (Her pro secret: Try to finish the gallon by 6 p.m. so you're not peeing all night long!)

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Miranda Kerr has said her quickest (and easiest!) get-toned trick is to remain active, even when she's not working out. "If you're sitting at an office desk all day, you can clench [and] tighten different parts of your muscles," shared the 38-year-old Victoria's Secret alum. "I do it all the time when I'm in the car or on the way to the airport. [I'll squeeze] my butt or do my calf muscles." She noted that while it doesn't have to be strenuous, "it's important to get the blood flow pumping."

Lily Aldridge stays fit all year round but confessed she takes things up a notch in the weeks leading up to a big runway show. "I start about two months ahead, so I can get in top shape healthily and steadily, and have time to feel good," the model, 35, said. That means sticking to a diet of mostly lean proteins, low-glycemic fruit and veggies — and nixing things like alcohol and salt! "The big thing I cut out is wine," she's said. "And then a week before the show, I stop salty foods."

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Vanessa Hudgens dropped 10 pounds in one month when she swapped empty carbs with foods higher in fat, similar to the popular keto diet. "When I ate carbs, I would get that dip in the afternoon, where I felt really sluggish," the actress, 32, noted. (On a typical day, she'd eat an avocado, eggs and bacon, chicken salad and salmon or steak with sautéed veggies.) "When I'm off carbs, my energy stays consistent throughout the day."

Looking for an instant reset? Follow Salma Hayek's lead with a juice cleanse (she's such a fan she created her own juicing company called Cooler Cleanse!). "After doing [one], I'm motivated to eat healthier and not emotionally," the 54-year-old actress revealed. Fellow stars like Jessica Alba and Gwyneth Paltrow swear by the practice too. "Cleansing is like my meditation," added Hayek. "It makes me stop, focus and think about what I'm putting into my body."

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Heart-pumping sweat sessions have done wonders for stars like Jennifer Lopez, Carrie Underwood and Kim Kardashian. And Kardashian recently revealed that adding sprints to her strength training has made an even bigger difference. "Been sprinting every day!" the 40-year-old star wrote via Instagram Stories alongside a clip of herself on a treadmill. "I've been seeing changes!"