Runner/writer Matt Fitzgerald published a blog on how to avoid overtraining by deliberately undertraining. From a personal perspective, it made for interesting reading mainly to remind me how completely the perils of overtraining have disappeared from my swimming.

What is most interesting and satisfying about this is that when I was young and strong – in my teens and early 20s – I was overtrained virtually 100 percent of the time but never realized it. Each of my 4 seasons of college swimming, from 1968-72, was shadowed by injury and extreme fatigue. My final two seasons, as a college junior and senior, were frustrating, even depressing for how hard I worked and how poor my results were. As my race times got slower, my response was to work harder, and my times got slower still. Toward the end of my senior season, my times in the 1000-yard freestyle, consistently under 11 minutes two years earlier in only my second year of serious swimming, were barely below 12 minutes.

Yet now, just a year short of turning 60 and swimming much more endurance-intensive events – my prospective English Channel swim next August will take at least 12 hours – I never experience the kind of training fatigue, or staleness, that was common when I was a lad of 20 racing in events that lasted about 12 minutes.

Here are several excerpts from Fitzgerald’s blog:

If you have been an endurance athlete . . . you have probably heard the axiom, “It’s better to be 10 percent undertrained than 5 percent overtrained.” It conveys the idea that fatigue hurts performance more than fitness helps it.

Take me, for example. It has been a long time since I completed a training cycle that yielded a satisfactory peak race result. Most have been ruined by injuries, one by overtraining. My approach has been to train as hard as necessary to achieve my goal . . . The methods I have used to avoid overtraining and injury have been to increase my training load gradually and to listen to my body and rest and recover whenever necessary. But these methods have proven themselves to be inadequate.

Fitzgerald’s experience and his recommendations on how to avoid overtraining, reveal a critical distinction between swimming and other “endurance” activities. Performance in swimming – including distance swimming – is decided 80% or more by efficiency and 20% or less by conditioning. On land it tends toward the opposite ratio.

Thus, if you train intelligently, there should be virtually no chance of having a swimming performance undermined by overtraining. In contrast to Fitzgerald’s experience it has been many years since I’ve swum a race that fell short of what I felt was my potential. I credit this to the fact that I train to ‘grow’ brain cells while he trains to ‘grow’ capillaries.  And when I race my performance is influenced far more by the quality of my neural – rather than aerobic – functioning.

And it’s virtually impossible to overtrain the brain and nervous system.