I'm not a huge fan of jogging on crowded sidewalks even in the US, and I expect many sidewalks in Tokyo and Osaka will only be more crowded.
What locations in these cities would you recommend for jogging?
In Tokyo I will be staying in Kabuki-cho in Shinjuku, so I was thinking of the Shinjuku-Gyoen park. They do charge 200 yen, though, so I'd love to hear of free alternatives. In Osaka, I will be staying two blocks west of Osaka Castle.
Recommendations in other parts of town would also be appreciated.