Here's a detailed description of the video: A man is doing dumbbell tricep extensions at a gym. He is wearing a dark tank top with a gray and white striped pattern. He appears to be straining with the exercise, his face contorted in effort. He’s using dumbbells. In the background, there are other people working out on various machines. The gym has exposed brick walls and standard gym equipment. Lighting is strong in some areas and dimmer in others.