At what intensity should endurance athletes train?

Posted October 3, 2007 at 09:00 AM by Mark Scott

Section: His Fitness, Cardio Training

One question that some endurance runners ask themselves is how much of their training they should be dedicating towards higher intensity runs and how much of their training is better off at low intensity.  The common thought would be that since they are training for endurance, they should train in a similar manner.  Some coaches and professionals however believe that training at higher speeds will help to improve their total body conditioning better and thus simply transfer over to a better performance during endurance related events.

Some researchers recently set out to run some tests on just this.

The study was designed to compare the effect of two different training programs on endurance performance, one that comprised a great portion of training time in a lower intensity zone and a second that comprised more time in a higher intensity zone.

The test group consisted of twelve sub-elite endurance runners who specialized in the 5000 m race however also occasionally participated in cross country races that ranged in distance from 9 to 12 km.  They were assigned to one of two groups, either one that emphasized the low intensity training or one that emphasized moderate intensity training, as determined by a prior ventilatory and respiratory threshold test (so then researchers could correlate work protocols with heart rate experienced). The study was carried out for a five month training period.

Both groups also participated in some high intensity training, which was categorized as being above their respiratory compensation threshold and the total time spend at this intensity was the same for both groups.

The results of the study showed that there was a greater improvement in endurance running performance in the group that spent a larger portion of training time at the lower intensity than the group that spend the larger portion at moderate intensity. Since total time at high intensity was the same for both groups, this factor did not come into play. 

So the take home message here is that if you are training for an endurance related event, it will be smarter to spend more of your time training at an intensity that is more correlated with that that you will perform with, assuming you are doing some higher intensity training during the week as well.  The high intensity training used in this study would be beneficial to include in a workout as it will help to improve your overall VO2 max levels which will be of benefit.  It is the training that is right around the moderate level that proves to be unnecessary if you are strictly focused on running for endurance performance.

Resource sources and for more information:Impact of training intensity distribution on performance in endurance athletes. J Strength Cond. Res. 2007. Aug 21(3):943-9.; [picture]