From the list of exercises below, which exercise is NOT an exercise to strengthen the latissimus dorsi?

The reverse fly is the exercise that does not primarily target the latissimus dorsi. Instead, it mainly focuses on the muscles of the upper back and shoulders, particularly the posterior deltoids, rhomboids, and trapezius. This movement involves the horizontal abduction of the arms, which engages different muscle groups than those worked during exercises like pull-ups, lat pulldowns, and single-arm rows, all of which specifically target the latissimus dorsi.

Pull-ups, lat pulldowns, and single-arm rows are all effective in strengthening the latissimus dorsi, as they involve pulling movements that engage this large back muscle. This differentiation highlights the specific muscle focus of the exercises listed, clarifying why the reverse fly stands out as the one that does not serve to strengthen the latissimus dorsi.