outdoor training. young man doing sit-ups

20s abdominal abs action active activity adult athlete athletic attractive beautiful beauty biceps body bodybuilder bodybuilding boy builder building caucasian cheerful crunch energetic exercise exercising field fit fitness force goodlooking grass green guy handsome happy health healthy horizontal human joyful lawn lifestyle male man masculine muscle muscles muscular nature one outdoor outdoors park people person physical power shape sit situps sleeveless smile smiling sport sports sportsman sporty strength strong summer tshirt torso training ups vitality workout young youth