Over the past years I've taken the habit of ditching the car more and more often, and to jump on my run-down bike for the short trips (from/to work in Paris until last year- around downtown Brussels from this year).
appearantly, I wasn't the only one wondering if this was/is a healthy activity, sucking up exhaust fumes at 20km/h and what's more "biking the risk of getting hit by monster traffic"...
GRIST has an interesting discussion and concludes that "biking wins over all mechanized transport".
So .. get out there, you bums, get some exercize: but be prudent and make sure your brakes work, you wear a protective helmet and fluorescent jacket, ankle straps to keep your trousers from getting snatched by the chain.... yakayakayakayaka....
In my opinion: it's great to de-stress, but the risks are important, but then again, not all of us have showers at the office...