How 'Superman' actor David Corenswet ate and trained to get buff for the movie, according to his personal trainer

Tech Insider : Business, Style
A composite image of David Corenswet in 2019 and 2025.
 David Corenswet in 2019 and 2025.

Andrew H Walker/Variety/Penske Media via Getty Images; Ethan Miller/Getty Images

A busy doctor says he lost almost half his body fat in 3 months with small changes to his routine

Tech Insider : Business
A composite image of a man posing shirtless before and after weight loss.
A 35-year-old man cut his body fat almost in half with full-body workouts, progressive overload, and smaller portions.

Courtesy of Simon Doyle/Adam Enaz

The first woman to complete the Boston Marathon is now 78 and runs most days. She shared 3 tips for getting fit at any age.

Tech Insider : Business
Composite image of a woman running, wearing a vest that reads,
In 1967, Kathrine Switzer became the first woman to officially run the Boston Marathon. A race official tried to stop her (right).

Kathrine Switzer/GALE Partners

6 red flags to look out for when hiring a personal trainer, according to fitness professionals

Tech Insider : Business, Style
A personal trainer helping a woman do reps with a weight.
Hiring a personal trainer is an investment, so it's important to choose the right one for you.

Blanscape/Shutterstock

Celebrity personal trainers share the 3 biggest mistakes people make when trying to get fit and lose fat — and what to do instead

Tech Insider : Business
A composite image of Don Saladino with his clients Ryan Reynolds and Blake Lively on a red carpet, and Magnus Lygdbäck with his client Gal Gadot by the River Thames.
Don Saladino with his clients Ryan Reynolds and Blake Lively (left) and Magnus Lygdbäck with his client Gal Gadot.

Courtesy of Don Saladino and Magnus Lygdbäck

Why extreme fitness is booming: 'I got kind of addicted'

Tech Insider : Economy, Business
Illustration of people running.

Dan Page for BI

How Gordon Ramsay stays fit at 58, from his diet to the one exercise he can't live without

Tech Insider : Business
Celebrity chef Gordon Ramsay at an event wearing aviator sunglasses and a black T-shirt as he smiles with his mouth open.

Kym Illman/Getty Images

An ex-YouTuber with 6.5M subscribers is now an entrepreneur and investor. Here's how he stays fit whilst running his businesses.

Tech Insider : Business, Style, Travel
Caspar Lee smiling and holding his phone to talk into it.
Caspar Lee is an ex-YouTuber and entrepreneur who uses AI to help him plan his exercise each week.

David Parry for Google Pixel

At my heaviest, I weighed 360 pounds, which got in the way of my job as a firefighter. I lost weight by paying attention to what I ate.

Tech Insider : Business
Two photos of a firefighter standing in front of a fire truck before and after he lost 140 pounds in weight.
Volunteer firefighter Clark Valery before and after his weight loss of 140 pounds.

Courtesy of Clark Valery

As a personal trainer in my 20s, I ate as little as possible and over-exercised to stay lean. At 34, I'm fitter, healthier, and stronger — but much less strict.

Tech Insider : Business
Sohee Carpenter sitting on a block.
Sohee Carpenter is a personal trainer based in California.

Bradley Wentzel

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