Originally Posted by FranckCisco
I thought cycling is quite dangerous, with probably of crashing and or death.
Not that kind of impact! While I'm sure colliding with a vehicle at 35 km/h would decently high-impact, when talking about low/high impact sports, usually it is in regards to one's skeletal system, ie: the impact on joints, etc. Running is higher-impact as the up-down motion with each stride places more stress on the joints, whereas swimming, as you're floating around in the water, places relatively little stress on your joints (and actually is the lowest impact sport of all, despite burning some decent calories).