How Do Top Runners Train?

I read this neat article earlier this week.  It looks at the actual training of top cross-country runners in Spain and their subsequent race performance.

The first thing I was surprised by was how much low-intensity training these runners did.  A full 71% of all training time was spent at a low-intensity (below 60% of VO2max).  21% of the training was done at a moderate pace, and 8% was done at a high-intensity.

Further, there was a direct correlation between time spent in the low-intensity zone and subsequent performance in both a 4k and 10k cross-country race.  Surprisingly, there was no relationship between time spent either at moderate or high intensities and race performance.

The authors also believe these proportions spent in the different training zones are applicable to other endurance sports.  They note that cyclists preparing for the Tour de France spend 70%, 23%, and 7% of their total training time in the low, moderate and high intensity zones respectively.

The idea behind low-intensity training is to build an aerobic pace.  At low levels of intensity, there is less work done by the muscles and more work done by the heart and lungs. 

This whole study was very eye-opening for me.  Many fitness writers are big on high-intensity and believe that only intensity can lead to better performance.  This study shows it may be the opposite: more time spent at an easy pace yields bigger dividends in terms of endurance performance.