I enjoy riding my bike around town and back and forth to the gym were I participate in an hour+ cardio/weight class three to four times each week. I am able to fit in an extra pure cardio session (two hour plus cycling and elliptical session at a 145 average heart rate) about every other week. That's about all I have time for.

I have participated in several longer distance rides but I find that either my calves or quads begin to cramp at 20-30 miles. I rode 44 miles last weekend in an attempt to "ride my age" but came up eleven miles short due to my quads cramping up.

I have a 3 liter camelback that I use (often) to stay hydrated.

What have you found to be the best way to avoid cramping and to bridge to riding longer distances? Is it a matter of riding long and often enough that your legs acclimate to the distance or that, plus proper hydration/electrolytes? I'd like to complete a metric century this fall, with the hope of completing a full century in 2015.

Thank you for any suggestions you can provide.