An area outside the nation’s highest court became a workout zone on Friday as supporters of Supreme Court Justice Ruth Bader Ginsburg rang in her birthday.

In honor of her turning 86, fans of Ginsburg – who is known for her rigorous exercise regimen – assumed the plank position outside the Supreme Court in Washington, while belting out “Happy Birthday,” The Associated Press reported.

AS RUTH BADER GINSBURG TURNS 86, HOMETOWN BROOKLYN PLANS CELEBRATION FOR SUPREME COURT JUSTICE

Leading the exercise was Bryant Johnson, the justice’s own workout instructor, while her son James was also in attendance.

At least one person in the group was photographed sporting a black robe and white lace collar, mirroring Ginsburg’s trademark look.

The justice’s routine includes push-ups and planks, the outlet reported.

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Ginsburg left a message for the group of supporters with Johnson, he told AP. She wanted him to relay that for the first time since she underwent surgery for lung cancer in December, she has "been able to do the planks the correct way and the push-ups.”

The court announced late last year that Ginsburg underwent a pulmonary lobectomy at Memorial Sloan Kettering Cancer Center in New York City after two nodules in the lower lobe of her left lung were discovered. The discovery came incidentally during tests, after she fractured several ribs during a fall in November.

Fox News’ Alex Pappas and The Associated Press contributed to this report.