I've always been interested in the mix between "base training," lower intensity, steady volume, presumed to build a base of fitness, and "speed training," which is more intense and designed to build raw power in muscles. The theory of periodization says to spend months in the base training mode, then at an appropriate time, lower the volume in favor of some speed training. Prior to a race, when you want to be at your best, you rest, do some light workouts, and hopefully your body grows and adapts to peak right at race time.
Unfortunately, about 90% of the writing I've read on this methodology only explains the concepts, but doesn't reference good studies nor creates a mathematical method to determine when to start shifting from one type of workout to another. So I guess it'll be up to me to experiment :).
I started my base training in December with an intent to do 4 months of just pure volume. In December I:
swam: 35,000 yards
biked: 220 miles
In January I:
swam: 36,700 yards
biked: 241 miles
During that two months I've lost approximately 6 pounds, but my body composition changes make me think there is likely an additional amount of fat that has been traded for muscle (probably not too much). My swimming has measurably improved, but my biking times are actually a tiny bit slower than what I was riding in October of last year.
More to come on the experiment of the human body!