Two best friends took to Instagram to reflect on how much they’ve changed since 2013. On the outside, 28-year-old pals Aerin Gaines and Gwen Swanson have become more fit. And on the inside, they’re more confident and positive than ever. To celebrate their progress on both fronts, they shared these before-and-after photos.

RELATED: 3 Ways Your BFFs Can Improve Your Health

“There have definitely been plenty of ups and downs, but one thing is for sure – this journey is beyond worth every struggle,” they captioned their post. “Our health is worth it. Our happiness is worth it.”

These BFFs tell Health that they’ve been inseparable since meeting 16 years ago and have always had an honest, open friendship. When they first teamed up to improve their health, they admitted that they had a lot to learn about wellness.

“We honestly started because we wanted to ‘get skinny,’” they say. “But then we quickly discovered a deeper passion for health and fitness. We realized it feels good to feel good and looking good was just a bonus.”

From workout videos to meal prep ideas, Gaines and Swanson share uplifting words to motivate their followers—and each other. They keep each other accountable and serve as sounding boards offering advice and support. While they stay active together, they’ve each found the best diet and exercise regimen that works for them individually.

RELATED: What It’s Really Like When Your Best Friend Gets Cancer

“I have a deeper passion for nutrition and studied it a lot in school and my free time,” says Gaines. “But I honestly hate to cook, so making healthy meals that taste great, but are super simple, is my jam! I also discovered that I love to run, but Gwen does not.”

When Gaines is running, Swanson is spinning.

“I’ve always been the more active one, and after we started this journey I knew I wanted it to be my career,” says Swanson, who has since become a group fitness instructor. “I totally fell in love with cycling. Getting stronger is the best feeling, [and] pushing your body to do things you didn’t think you could do is empowering.”

Despite their positivity and encouragement on social media, they acknowledge that it’s not always easy to stay on track.

“Progress is never linear,” they say. “Embrace the journey, both the successes and the struggles because there will be both. Self love is key.”