Even running can be time efficient. When I lived in almost-central London (Wandsworth), the office was 7 km in towards the center. Running took 40 min., while t

Even running can be time efficient. When I lived in almost-central London (Wandsworth), the office was 7 km in towards the center. Running took 40 min., while the tube or bus was 50 min. door-to-door. So running plus a shower was no slower than public transport, plus you save time on never having to go to the gym. And of course significant financial savings on cutting the gym membership and 80-90% of the public transport expenses. (Not a native Londoner, so I was too afraid of traffic to bike it.)