But one woman’s recent Instagram post has shown the startling difference between doing cardio and doing weights at the gym.
Bikini designer, Karina Irby recently shared a before and after picture with her 615,000 followers.
The Australian woman is skinny in the before photo and has more noticeable curves in the after photo.
She captioned the image: “Looking though old photos and I almost fell off my chair.
“Photo on the left is 18-year-old Karina, [I personally think] I was sickly skinny and unhealthy.”
Karina continued: “I’m so thankful I got educated and not just from a ‘looks’ perspective but from a health and fitness perspective.
“Not an ad, but a definite shout out to @bikini.body.burn for opening my mind and shoving some weights and protein in there.”
The 27-year-old credits her curvy physique solely to lifting weights and eating protein.
In prior posts, Karina has been candid about how she used to only do cardio during her workouts.
A post from June read: “I loved going for long runs. I had no idea about what foods I should be eating and no idea about health and fitness in general.
“I wasn’t eating nearly enough of the right food, or food at all to be fuelling my body.”