Join Date: Nov 2000
Location: New Orleans, LA
Building strength or cardiovascular fitness is a process of overstressing muscles/cardiovascular system to encourage the body to adapt to the increased stress by repairing/growing new muscle fiber and improved oxygen uptake. After a hard overstressing workout the body needs rest to have the energy and materials available to do the rebuilding. As one author put it, you don't build strength while you work hard, you build strength when you rest. To this end most training programs recommend 2-4 days of hard work (depending on your current level) with 1-2 recovery days for the rebuilding in between the hard days. Recovery rides should be relatively short, say not more than an hour, and "guilt-inducingly slow". HR of about 65% is often quoted but you have to be aware that you can push too big a gear and still maintain HR of 65% but you may be working your legs too hard. On hard days go really hard; on easy days go REALLY easy.
Fred Matheny's Complete Book of Road Bike Training is an excellent source for anyone from recreational riders who just want to be a little faster to experienced racers.
If it ain't broke, mess with it anyway!