I can bike for hours, but still with my weight, running is hard for me. Running is a better workout for me, as my heart rate gets up quicker and stays at a higher state while running. I am only running on a treadmill as it isn't safe to be outside on our street or sidewalks because of ice and snow.
Running is a good thing to do also. I don't count that a bicycle miles, I only count it as running miles.
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2007 Jamis Ventura Comp
2006 Jamis Explorer 2.0
2000 Specialized Hardrock (bought used)
Swim, Bike, Run and sounds like fun