Serena Williams, Olympia Ohanian and Adira Ohanian 'Work Out' In Adorable Christmas Video

Serena Williams knows a thing or two about training with a sister. Now, she's imparting that wisdom onto her own daughters.

The tennis icon spent a little time Christmas morning helping daughter Olympia "train" her younger sister, Adira. The very sweet "workout" consisted of Olympia lifting Adira up by the arms and laying her back down, while Williams spotted and coached her through the movements -- in French, no less.

"We all work out in this family, " she captioned the photo.

Unsurprisingly, Olympia has plenty of sports savvy to share with her younger sister. She is already basically a tennis pro, soccer star and golf champ.

Physical fitness is important in the Williams / Ohanian household, but mental health is held in equally high regard. Back in November, Williams shared an important (and relatable) message to Twitter on a day she wasn't feeling her best.

"I am not ok today," she wrote. "And that’s ok to not be ok. No one is ok every single day. If you are not ok today I’m with you. There’s always tomorrow. Love you."

It looks like Williams may have also been inspired by her daughter's workout routine.. Just one day after Christmas, she posted a series of gym selfies.

Like mother, like daughters.