Kim, 34, who is pregnant with her second child with husband Kanye West, hit the beach with her sisters, mother and a trainer, reported Aceshowbiz.
During the session Kim was photographed living up her shirt and revealing her burgeoning bump.
Khloe and Kourtney Kardashian joined Kim for the group exercise donning an all-black ensemble too.
Kendall and Kylie Jenner, who were spotted on the family trip, were not seen during the workout.