Tokyo has 2 airports, and both of them have Anytime Fitness gyms nearby. It is not within the airport buildings, and you have to take a bus or local train for a few stops to get there. Click each icon on the map for address and tips.
Haneda Int’l airport - The closest gym is Anytime Fitness Otorii. This gym is a 3 stop train ride from Haneda airport, (10 min) on the Keikyu Airport line. You get off at Otori station, and it is 3 min walk to this gym. Haneda Airport is not far from the Tokyo main area, where there are many Anytime Fitness gyms in convenient locations (see here). So, if you are staying in Tokyo and want to work out before flying out, it would be better to go to one of them first and then go to the airport.
Narita Int’l airport - The closest gym is Anytime Fitness Narita Airport. There is a free shuttle bus from the 2nd terminal, going to a hot spring bath facility nearby called “Sora no yu” which is 24hrs open and costs about $15 per visit. It takes only 5 min from the airport. Anytime Fitness Narita Airport is right next to this. So, it is a great idea to workout first and take a hot spring bath !