LSD

Today I did five laps of the February strength circuit and paddled the surf ski for 90 minutes.

At this still-early point in the season, my paddling regimen consists of, well, lots and lots of paddling.  By logging many hours of steady, aerobic paddling, I'm building my "base," something that athletes in all endurance racing sports (and I think most other types of sports) do.

When I was running in high school and college, we referred to the typical base-building session as "LSD," which stands for "Long Steady Distance."  I don't know whether this term predates the 1960s-70s popularity of  psychedelic drugs, but all the runners and coaches I knew seemed to throw it around without giggling.

Biology was not one of my better subjects in school, but here's what I understand is going on when you string together days, weeks, and months of steady aerobic exercise:

Your heart muscle gets stronger to meet the demand for a greater volume of blood.  This blood gets pumped to the muscles doing the work.  In the case of paddling a kayak or canoe, this would be primarily the arms, shoulders, and abdominal muscles.  In the early going, when you're out of shape, the muscles are not able to process the amount of blood they are receiving.  But as time goes on, during the recovery periods between workouts, new capillary beds form in the muscles and enable the muscles to handle the increased volume of blood more efficiently.  Your body also forms more mitochondria, cells that convert the oxygen in the blood to energy.

Eventually, your body becomes a much more efficient machine for performing the required movements of your sport.  And the blood-processing infrastructure--what exercise physiologists call your "VO2" system--will be needed later on when you move into anaerobic exercise: it will facilitate your recovery from super-intense workouts by washing excess lactic acid from your muscles.

On the technical side, these steady distance sessions are the time when a paddler develops a smooth, fluid, efficient stroke.  It's much easier to concentrate on good form when paddling at a comfortable speed that allows conversation with a fellow paddler than when paddling as hard as possible.

So these days I'm doing plenty of LSD, nudging up my volume of paddling week by week.