My bf and I have found a great form of exercise. We bike 6 miles to a Lake, run a 5K, and bike back.
We do this routine 3 times a week. This is fun because running by itself can be uninteresting, so we added biking to our exercise. VERY VERY FUN.
We also have a good diet, make sure we eat fish and a low fat diet. I think for anyone who is trying to get into shape, try this exercise. it is very great and only requires 3 times a week .

I think biking is more fun than running. I started out as a runner but as I got older and put on more weight, my power to weight ratio soon worked against me. While on a bike, I get less pounding, the the power to weight ratio is not that big of a deal unless I'm climbing for a long ways.

For the same amount of energy spent, you can cover greater distances at higher speeds without the pounding. Depending on your aerobic fitness, you can even carry on a prolonged convesation while riding.

I like to run one or twice a week, I should try that. There is a nice three mile loop through a local park about five miles away, think I'l ride there, run the path then ride home this week.

Yes I think it's a great form of exericise for people who don't have a lot of time in the week and work many hours.
To burn the same amount of calories biking as running takes more time.
I do this exercise to keep fit. I am 27 and I think having a healthy life style is important. I've helped one of my friends lose 100 pounds (no joke). I have never been over weight, but I love helping people get into shape as my bf and this keeps me in shape definately .

I'm signed up for a Duathlon this October so I just started training for the running portion of the race. It's going to be a 2.6 mile trail run, 6 mile mountain bike trail and then another trail run of 2.6 miles. Moutain bike portion I have no problems with, but I know I'm going to get my tail panked on the running. But as long as I can finish I'll consider it a win for me. (Since a year ago I was over 400 lbs)

Ron