Savannah Guthrie Stuns in Swimsuit of "Favorite Memory"

Today host Savannah Guthrie is getting some very sweet birthday wishes from friends and coworkers, including co-host Al Roker. Roker posted a picture of himself and Guthrie, 52, lounging in a pool while covering the Winter Olympics. "Happy Birthday to one of the sunniest, special folks around, my Savvie G," Roker captioned the post. "Favorite memory," Guthrie commented. Here's how Guthrie stays fit, happy, and healthy.

Guthrie tried the keto diet, and says it made her mind sharp but sapped her energy. "I feel less energy in the sense that I don't want to work out any more," she said on the Dr. Oz Show. "I think I need those carbs to want to go on a run or do aerobics or do whatever I might do, but Hoda (Kotb) says she thinks it's making my mind sharper… I'm still kinda doing it. It's like a lot of meat and cheese. It's opened up some things that I would never let myself eat a lot of, such as cheese and bacon, so I like that."

Guthrie fasts and chooses food that makes her feel good. "I love healthy snacks that feel like a treat!" she tells First For Women. "I really like edamame and cucumbers. I'll take a cucumber, peel it and eat it to feel more hydrated during the day. The crunch of both of those scratches that snacking 'itch' for me. Right now, I'm also intermittent fasting for 16 hours a day. In the morning, when I'm waiting to eat my breakfast, I'll grab some sparkling water to stave off cravings. The truth is that I'm a 48-year-old who had two babies in her 40s, so I'm just trying to be more healthy by making good food choices, getting more exercise, sleeping a little bit better every night and staying strong so I have more energy to play with my kids."

Guthrie swears by low-intensity workouts such as yoga and walking to stay fit and happy. "I don't put pressure on myself to do a big workout — just doing something small and enjoyable makes a world of difference!" she tells First For Women. "For instance, doing a few minutes of yoga each day has become such a stress reliever for me lately. I did a 30-day yoga challenge, and it became almost like a meditative practice. It helps me feel stronger, the stretching is a major stress reliever and it puts my mind in the right place. I also try to walk a lot. My daughter's school is two miles away, and I'll walk her there if I can. Having those few minutes of not looking at my phone and just moving is amazing!"

Guthrie hasn't always been confident about her appearance. "It's a lifelong struggle for me," she tells Health. "I've never once felt good about how I looked on the outside. I think all of us women spend so much time not feeling like we measure up. And what a waste of energy. I'm not there yet, but that's my goal."

Guthrie relies on family and faith for a fulfilling life. "My strength comes from my faith," she tells First For Women. "Every morning I say my prayers. It's easy to get distracted or anxious, but faith is my North Star. Then, of course, my family: My husband, Michael, is my superhero. Knowing that he has my back is such a comfort. My mom, sister, brother and I are all really close. We're in touch every day, either by phone or text. Having that family support makes such a huge difference."