A cinematic, realistic video of a young athletic girl running on a treadmill in a modern gym. She wears stylish fitness wear—sports bra and leggings—slightly glistening with sweat, showing determination and focus. The treadmill belt moves smoothly as her stride is powerful and rhythmic. Soft natural light enters through large glass windows, creating dynamic highlights and shadows. The camera starts with a side profile shot, then slowly moves to a front-angle close-up capturing her confident expression and controlled breathing. Background includes blurred gym equipment and subtle motion for depth. Ultra-realistic, 4K quality, smooth motion, shallow depth of field, motivational fitness commercial style.