Yesterday I decided to leave the car and walk the quarter mile to the shop, as suggested by the doc. What I discovered has put me right off and I'll walk in the park from now, thanks.
The problem is traffic exhaust. From even my gentle stroll I could really feel it in my lungs and it occurred to me I was doing more harm than good.
It then struck me that cyclists do the same thing only with their hearts pounding and lungs working full pelt. Surely this can't be good. Has any research been done?