National Fitness Day is observed in the United States every first Saturday of May. It was launched in 2017 by fitness enthusiast Kim Bielak, who was inspired to create the day after her first marathon in 2015. The day celebrates strength and empowerment through fitness, encouraging individuals to find joy in maintaining a healthy lifestyle. Participants can engage in various activities, such as attending local events, wearing black workout clothes as a symbol of strength, trying new healthy recipes, or setting personal fitness goals. The inaugural event, called Class for a Cause, raised money for Girls on the Run, a nonprofit organization aimed at empowering girls through physical activity. Although the official website has not been updated since 2020, fitness enthusiasts continue to celebrate the day and share their experiences on social media using the hashtag #NationalFitnessDay.