Simple Response

Yes, in the sense that the rowing machine requires both the upper and lower body. However, no in the sense that the adaptations created are cardiovascular adaptation and not musculature adaptations.

Defining Full Body

For me, personally, a full body workout is something that creates adaptations in non-localised parts of the body. This means that a full body workout will target both the lower body and upper body in the same session. An example of this might be performing a deadlift and a bench press and creating strength or hypertrophy adaptions within the same session.

Is Rowing A Full Body Workout

A rowing training session is not a full body workout then as the intent of the session is to create adaptations in the cardiovascular system and not create strength or hypertrophy adaptations. Yes the rower requires some upper body pulling, but for the vast majority of individuals this level of resistance will not create any meaningful adaptation in terms of strength or hypertrophy.

However this is all based on my definition of what a “full body workout” is. If your definition of a full body workout is a workout that moves the entire body without emphasis on adaptations being made then yes, rowing is a full body workout.