The 31-year-old Olympic gold medalist shared a throw back photo of the day Boomer was born, writing, "One year ago, Nicole and I had the privilege to welcome Boomer to this world. For me, it's the best thing that ever happen to me!!"
Nicole also took to Instagram to share a sweet snapshot of Boomer, sporting comfy-looking black pants with white stars. The mom accompanied the pic with a handful of Boomer's milestones.
"On and off his cars, in and out of his wagon, climbing on everything but also turning around to get down, drinking from his own cup, making a drum out of anything, clapping when he hears an audience clap and so much more," she wrote. "Happy early birthday to the most special gift we could have ever asked for ?."
Days before Boomer's big day, his parents were getting ready to celebrate with their tiny tot. "I think Boomer was practicing for his cake smash this weekend with his morning," wrote Nicole on Instagram. The little one also received an early birthday gift, a monkey stuffed animal -- which he happily accepted!