Doutzen Kroes in a bikini in Miami Beach, FL. on March 23, 2013. Credit: Pichichi/Splash News Online

There's no doubt about it: Doutzen Kroes has a killer body! In town to support her DJ husband Sunnery James performance during Miami's Ultra Music Festival, the 28-year-old supermodel spent her downtime parading her famously fit figure in a series of skimpy bikinis.

On March 23, the Dutch beauty showed off her six-pack abs in a leopard print string bikini while frolicking in the ocean. The following day, Kroes -- who wore another printed string bikini -- was photographed teaching her son Phyllon how to swim at their hotel. Wearing water wings and blue swim trunks, the 2-year-old repeatedly jumped into the pool -- with his mother's help, of course.

Kroes stays in shape thanks to rigorous workouts with her trainer, former boxing champion Michael Olajide; the pair have even documented their exercises in a series of Victoria's Secret YouTube videos.

The model shared other diet and fitness secrets during a fall 2012 interview with Pop Sugar. "I always eat in moderation. For example, if I order french fries, I'll have a salad. And I share with my friends -- I share the fries. I don't tell myself to not eat anything, to stay away from all the sugar, the fries and good fried foods," Kroes explained. "The mom thing helps, too, because I'm running around after my son."