I am a relative newbie and had read on this forum and other places how important cadence is to keeping one most efficient in cycling without completely fatiguing the leg muscles. My eureka moment came yesterday. I have been cycling seriously for approximately 2 months with shorter rides leading to long rides of 2 hours/30 miles distance. After those rides, my quads felt like someone had beat them with a rubber mallet. Yesterday I decided to intentionally try to slow down somewhat by riding at a higher cadence and a lower gear. I was truly amazed that after a 1 hr. ride of approximately 14 miles, my legs felt great. Did a similar ride today and legs feel fresh. What surprised me was that I sacrificed little if any speed by changing my cadence/gear input. Overall what I did was ride in one lower gear from what I felt like I naturally needed to ride in according to conditions, hills, long flat stretches, etc. I also noticed that my heart rate stayed more stable with little huffing and puffing. I have a Garmin Forerunner 305 with a heart monitor. Thanks to all for their knowledge and input that I gain from the forum. Sometimes I just need to listen!