pretty teenage girl in sportswearin a stadium straightens her hair into a ponytail

abdomen adult arm athlete athletic athletics belly bikini black briefs clothing competition field fitness fun girl hair hairstyle happy isolated jogger jogging joy limb longhair marathon muscle neck pink ponytail portrait poses posing pretty runner running schoolgirl slim smiling soccer sport sports sportsbra sportstop sportswear sporty stadium straightens teen teenage teenager thigh top track training undefined underwear wear youth