Page Six reports Bündchen was seen with jiu-jitsu instructor Joaquim Valente at Koji in Provincia de Puntarenas, Costa Rica, along with her children Benjamin and Vivian.
Bündchen had previously posed alongside Valente and his brothers Pedro and Giu during a shoot for Dust Magazine in 2021 and had shared a post calling the Valente brothers "Awesome teachers" while training in jiu-jitsu in February 2022.
Bündchen and Brady announced their divorce on October 28.
"With much gratitude for our time together, Tom and I have amicably finalized our divorce," Bündchen wrote at the time. "My priority has always been and will continue to be our children whom I love with all my heart. We will continue co-parenting to give them the love, care and attention they greatly deserve.
"The decision to end a marriage is never easy but we have grown apart and while it is, of course, difficult to go through something like this, I feel blessed for the time we had together and only wish the best for Tom always.
"I kindly ask that our privacy be respected during this sensitive time."
Brady and Bündchen reportedly had "an ironclad prenup" prior to their marriage, which led to their quick divorce settlement last week, sources with knowledge of the situation told Page Six, on November 2.
Brady, who turned 45 in August, announced his retirement, then un-retirement this offseason ahead of his 23rd NFL season.
Brady is the NFL's all-time passing leader for yards and touchdowns, as well as quarterback wins, among numerous other records.
The San Mateo native spent his first 20 seasons with the New England Patriots, leading the franchise to an NFL record six Super Bowl championships (tied with the Steelers), before joining the Buccaneers as a free agent in March 2020, which resulted in Tampa Bay winning its second Super Bowl in franchise history, becoming the first NFL team to win a Super Bowl in its home stadium, in February 2021.