It takes just one watch of La La Land or Battle of the Sexes to realise you wouldn't exactly want to challenge Emma Stone to a fight (or dance-off, for that matter) given her proven athleticism over the years.
And who's to thank for the 29-year-old's incredible agility, muscle and mental strength?
Enter Hollywood personal trainer, Jason Walsh.
Having worked with the likes of Irina Shayk, Alison Brie and Jennifer Anniston, Walsh was famously tasked with building Stone's stamina and energy for the Oscar-nominated musical's numerous tap dance numbers and singing performances.
As well as that, the celebrity-favourite PT was also the man behind helping the actress gain 15 pounds in muscle for her role as tennis legend Billie Jean King in her latest film.
Explaining the star's dedication to her role as King, Walsh told W magazine: 'This is somebody's story that she's taken on. She wanted to make sure she could do everything possible to portray Billie Jean King in the right way.'
However, as Emma has previously admitted to having a 'deep-seated rage' when holding heavy weights above her head, it sounds like Walsh certainly had his work cut out for him.
Here are his top tips to training like Emma Stone, whether you're donning the tap shoes or tennis trainers:
The deadlift is the most reliable form of exercise for all round fitness
Given Stone's slender frame, Walsh admits he had to modify the star's shape so it looked and performed like an athlete's on the tennis court for her role as King in Battle of the Sexes.
The trainer revealed to W: 'As far as the tennis focus, we did do a lot of shoulder strengthening; rotational, anti-rotational work, things like that because of the motion of and how the body works for her. Her legs are strong. Her butt was extremely strong which stabilises the hips and helps with everything else.'
'If you're going to move like a tennis player you've got to have that foundation where you can move like that. What we did is we gave her the ability to do that without breaking down and getting injured.'
For anyone hoping to build strength and power, the fitness guru told Healthista: 'It is, and always will be, the deadlift and variations of the deadlift. Its a complex movement that incorporates every major muscle group working together. It's very important.'
Strength comes before cardio
'3:1 Cardio is nothing if you don't move well,' he added. 'Staying strong supports the skeletal system, stabilises joints, makes your cardio safer and more effective.
Her legs are strong. Her butt was extremely strong which stabilises the hips and helps with everything else
'If strength training is done right, you get plenty of cardio from lifting as well. Cardio comes secondary.'
In terms of Stone's strength, Walsh admits he wasn't the only one impressed with how far she came during her training sessions for her latest role.
'Emma was impressive in the gym, when new guys would come in and start training with us, they would literally just be in awe of the stuff that we were doing,' he told W. 'Jaw dropped. She could run circles around them.'
Don't ban carbs
When it came to Emma's training to play the tennis champion, Walsh explains to W magazine: 'We really had to tinker with her calorie intake and diet, along with upping the amount of training that she did for Battle of the Sexes. When she trained for La La Land, we worked out three to four days a week.
If strength training is done right, you get plenty of cardio from lifting as well.
'With Battle of the Sexes we did five days a week and sometimes two times a day. Between the increased frequency of workouts and addition of calories that were good, healthy calories, she stayed pretty lean.'
As a result, Walsh advises gym bunnies: 'Eat breakfast, taper carbohydrates throughout the day, and don't eat late.'
Limit your sugar intake
'I limit all sugars, and I add UDO's Choice Oil to food daily for essential fats,' he told Healthista.
'That's where I get my energy from, not sugar. You could lose 10lbs immediately just from cutting out sugar.'
Discussing Stone's training for her role as King, Walsh had to alter her diet, slightly.
When she trained for La La Land, we worked out three to four days a week
'What really helped us with Emma, was having some really good shakes because when you're under that much stress, the kind of stress from lifting and pushing and pulling hundreds of pounds, the body's metabolism naturally is going to skyrocket,' he explained.
'People are like, "She's insatiable. She can't get enough food and she's hungry all the time. She wakes up starving." And that's natural. She's naturally going to want to increase the calorie intake, but sometimes it just becomes so mentally tough to actually eat a lot.'
If director Damien Chazelle decides to do a La La Land 2 in the future, we'll be ready.