Create a hyper-realistic, 4K portrait of a female model wearing sleek, form-fitting activewear leggings and a sports bra, set in a natural outdoor environment like a park or urban street. The artistic style will lean towards photorealism, with digital rendering as the medium. Use a wide aperture (f/1.8) to create a soft background blur, while focusing on the model's posture, emphasizing the flexibility and comfort of the outfit. Natural, warm sunlight will illuminate the model from the side, casting soft shadows on the fabric texture of the leggings. The background will feature trees or subtle urban elements out of focus, creating depth. Highlight the details of the fabric, such as the stretch and sheen of the material, and add light HDR effects to enhance clarity and color contrast.