1) Running has an appealing simplicity: very little equipment is required (just a decent pair of shoes), you can do it anywhere (city/country, on/off road), etc.
2) Biking is not some magical risk-free activity, you have to take care whichever you choose.
I'm pretty sure his point was that running in and of itself (outside of external factors such as other people on the road, etc.) is very detrimental to your health- specifically your knees.
Obviously doing any physical exercise you should be safe about it (wear a helmet while biking, have a light and reflectors if you ride at night, etc., and of course be conscious of your surroundings), but running solely by itself can be detrimental to your health because of the force you put on your knees on impact running on paved surfaces.
I assume that was his point. However it is not a given that running is "very detrimental to your health"; in fact that's a pretty bold claim to make without any evidence or indeed consideration of the health benefits. It's true that knee problems are a concern for some runners (and indeed participants in many other sports), and something frequent runners should be wary of.
Yes, I will agree that "barefoot" running is better on your knees than with standard running shoes- also running with proper form would be, but alas- almost no recreational runner will do either of these things, and it is especially hard to do so on typical running paths (such as, you know, roads).
Given the constraints of what we're given, biking is far better for your overall health than running.
I walked in to work this morning, during which time many runners passed me. None of the women--and most of them were women--were heel-strikers; from my past observations, few women are. And of the three men who passed close enough to see, all landed on the middle of the foot.
You don't need to run barefoot. Just tilt your foot forward and land on the ball rather than the heel. You can stick with regular running shoes and do this.
In my neighborhood, it's much harder to bike a long enough distance for a good exercise. You can get a much better workout using a smaller "track" when running.
Running isn't super bad for you. You need medium impact to build bone density, which is a major protective factor in old age.
Running has more bang for your buck, so to speak. Among other things, you burn more calories per minute, work more stabilizer muscles and strengthen your bones. Its easier to get the intensity up (speed and strength work, fat burning), and to keep the intensity low (endurance building).
Both of the sports will cause damage, as they are both straight line repetitive motion exercises. In either case you want to think of them as specific or specialized uses of your fitness, while creating proper base fitness like flexibility and muscular balance in the gym/yoga etc. would be your non-specific work.
Any time you go very specific you are going to find a weak link.
As a musician (string player) and programmer, my neck, back, and wrists are under constant stress, and I find biking tends to exacerbate problems with those joints. Also, I live in NYC. I can go run in the park, or I can ride my bike and get hit by a car. I know lots of people who ride their bikes in the city, and every one of them has been hit by a car, including me.
Some people simply like running for the pleasure it gives them. I guess it's the same with weight lifters. At some point the physique is a side-effect of one's regulard and healthy practice.
Note that sprinters as well as endurance runners have to lift some weight at one moment or another. When I run my first half-marathon I was surprised that my arms were more sore than my legs.
How many calories are burned biking-vs-jogging? I think biking (on flats) is extremely efficient, so I would imagine that and average person would burn more jogging than biking...For example, if I bike 7 miles, I don't feel it anywhere near as much as if I ran 7 miles...
For calorie burning short intensive work outs are better. For example, deadlifts or playing squash for 30minutes is comparable to multiple hours of jogging.
