Commuter cycling and sickness absence

http://www.ncbi.nlm.nih.gov/pubmed/20580736

Conclusion: "Cycling to work is associated with less sickness absence. The more often people cycle to work and the longer the distance travelled, the less they report sick"

The Health benefits of cycling outweigh the risks

http://www.ncbi.nlm.nih.gov/pubmed/20587380


Says (according to CTC's CycleDigest) that the health benefits of cycling are on average nine times greater than the risks associated with driving a car.

Cycling & Health - What's the evidence?

Also from CycleDigest

http://www.cyclingengland.co.uk/documents/FinalHealthreport-19.9.07.pdf
(3.62MB)

Report reviewing all the available evidence on the health benefits of
cycling, pulling it together in one place.