have you give thought on the whole "nonviolent" martial art? kinda contradiction in terms. i assumed that you have seen youtube videos of aikido? can you imagine what it would like to a body that gets thrown into a concrete paved street or a tree or a moving bus? using the earth to hit someone isn't what i would call "nonviolent".
as far as exercise goes, i go the gym to get extra workout on my non-aikido days. and wearing bright neon color body suit to the gym, in order to blend in, is highly recommended. please post picture if you do.
Compared to shooting someone or breaking their arm, I'd say Aikido is non-violent. We are giving a person a /chance/ to not get seriously hurt, despite them attacking us. I'd say if someone has hit the point in Aikido where they could drop a street attacker, they have put some real time on the mat.
Now imagine if someone put that same amount of time into something like Muay-Thai or Boxing and used that instead. I think we'd all agree that while effective, it would be a violent resolution as the person beings by trying to hurt another.
Remember the word violent definition refers to 'intent'. There isn't the intent to hurt someone in Aikido, although there is the chance to hurt them. However, if the word still bothers you I know several Aikidoka who prefer to call it a de-esculation art.