The modern workplace is undergoing a profound transformation driven by artificial intelligence (AI), hybrid work models, and increasing cognitive demands. While these changes promise productivity gains and operational efficiencies, they also risk deepening one of the most persistent and underappreciated threats to workforce health: sedentary behavior. Physical inactivity is a well-established predictor of chronic disease, including obesity, cardiovascular disease, and type 2 diabetes. Sedentary behavior, such as prolonged sitting independent of exercise, has emerged as a distinct and independent risk factor. In knowledge-based work environments increasingly shaped by AI, the structure of work itself may amplify exposures to sedentary behavior. This column explores how AI is reshaping physical activity and sedentary behavior in the workplace, not only as a risk amplifier but also as a powerful tool for intervention. The central question is not whether AI will influence worker movement, but whether organizations will intentionally design AI-enabled systems that promote health rather than undermine it.