New Study Finds Most Age-Group Triathletes Are Still Stuck in the Moderate-Intensity Rut

It’s been nearly a decade since I coined the term “moderate-intensity rut” in reference to the widespread habit among recreational endurance athletes of doing a plurality of their training at moderate intensity. At that time, very few athletes were even aware of the existence of the problem. But much has changed since then. The books 80/20 Running and 80/20 Triathlon, through which I endeavor to save athletes from the rut, have sold a combined 90,000 copies, and online versions of the books’ training plans have sold close to 70,000 copies. And these numbers only hint at the ripple effect of broadening awareness of the moderate-intensity rut.

But one thing hasn’t changed, and it’s this: The vast majority of recreational endurance athletes are still doing a plurality of their training at moderate intensity. The latest bad-news report from this front comes in the form of a study led by João Henrique Falk Neto and published in the journal Sports. Nine recreational triathletes kept detailed training logs during the final six weeks before an Olympic-distance triathlon and for two weeks afterward. They also completed questionnaires intended to assess their health and well-being, including the Training Distress Questionnaire and the Training Stress Recovery questionnaire.

The main purpose of the study was not to identify the training intensity distribution of these athletes but rather, as the authors put it, to “assess how their preparation for a triathlon influences their health and their levels of fatigue.” I’m not sure what Neto’s team’s hypothesis was, or if they even had one, but if they hoped to find that the subjects’ health or well-being suffered during the eight-week observation period, he was disappointed. No significant changes were seen in any of the relevant measures.

Personally, I’m happy about that, but I’m less happy about the way these athletes trained. The most surprising finding was that their training loads fluctuated drastically from week to week. One would expect some variation in training stress, of course, but these folks took it to an extreme, with all nine subjects literally doubling their training load from one week to the next at least once. What’s more, Neto’s team was unable to identify any coherent logic or pattern to these fluctuations. They had every appearance of utter arbitrariness. My own best guess as to why training loads were so erratic in this group is that they trained too much in their “up” weeks and had to compensate by scaling way back in the weeks that followed.

As the 80/20 guy, I was most interested in how these athletes balanced their training intensities. If Neto and company’s findings regarding training loads were surprising and head-scratching, their findings on intensity balance were predictable and dismaying. Perhaps I was naïve to hope that the 80/20 message had achieved statistically meaningful penetration in this population, but it clearly hasn’t.


As most studies of this kind do these days, intensity was divided into three zones. Zone 1 is considered low intensity, and is bounded on the upper end by the first ventilatory threshold, which corresponds to 77-81 percent of maximum heart rate. Zone 2 is moderate intensity, and has an upper limit marked by the second ventilatory threshold, which corresponds to 91-93 percent of maximum heart rate. And Zone 3, high intensity, is everything above the second ventilatory threshold. On average, the subjects were found to have completed just 47 percent of their combined swimming, cycling, and running in Zone 1, and in only two weeks of the eight for which data were collected did they spend more than half of their training time at low intensity.

I should mention that these findings are skewed somewhat by the fact that they were based on session RPE ratings rather than on heart rate data. Subjects were asked to assign an intensity rating of 1 to 10 for each session as a whole, and so, for example, a 50-minute workout containing 25 minutes of work in Zone 3 would be considered a 50-minute session in Zone 3 if the athlete assigned it a session RPE of 7 or higher. Even accounting for this rather sloppy approach to measuring intensity distribution, though, we can be certain the athletes in this study were doing nowhere near 80 percent of their training at low intensity.

I feel two ways about this study. On the one hand, I’m sad that so many recreational endurance athletes are training in a self-sabotaging manner. On the other hand, as a cheerleader for athletes in the 80/20 Endurance community, I see this widespread self-sabotage as a competitive advantage for “my people.” Competition does not begin when the starting horn blares; it begins on the first day of training. If you exhibit the judgment to find and use the most effective training methods and your competition doesn’t, so be it. Exploit your advantage to the fullest possible extent, and in the meantime I’ll continue to work on trying to reach the lost sheep.