Author + information
- Martin Burtscher, MD, PhD∗ ( and )
- Dominik Pesta, PhD
- ↵∗University of Innsbruck, Sport Science, Medical Section, Fürstenweg 185, Innsbruck, Tirol A-6020, Austria
We appreciate the findings reported by Schnohr et al. (1), but we feel that insufficient attention has been paid to the consequences of pace categorization by self-reporting. The investigators demonstrate a U-shaped relationship between the dose of jogging and all-cause mortality. Joggers were categorized as light, moderate, or strenuous joggers on the basis of the quantity of jogging and the self-reported pace (slow, average, fast). The use of the self-reported (perceived) pace makes sense from a practical and clinical point of view, but it is unjustified to assign fixed amounts of miles per hour to the pace categories without considering individual fitness levels. Everybody will agree that a pace of 7 mph will generate different cardiovascular responses and will be perceived differently by a 35-year-old elite runner than an 85-year-old amateur runner due to the huge differences in aerobic power (cardiovascular fitness) (2). Thus, the U-shaped association between the dose of jogging and mortality is likely to be true when based on the individually perceived pace, but is very likely wrong when based on absolute values. In our opinion, this is a critical point, because a pace of 7 mph is fast for a novice or an amateur runner but is a perceived slower pace for an elite runner. Professional endurance athletes usually perform >80% of their training sessions at light intensities (50% to 70% of their maximal heart rate) (3), and therefore, would be rated as moderate or even light joggers according to the categorization applied by Schnohr et al. (1). This is compared with novice runners who often train at too high intensities. Furthermore, numerous middle-aged and poorly prepared recreational runners start strenuous running programs after cardiovascular disease diagnosis. This means that over-ambitious amateur runners, rather than elite runners, are placed at the rising slope of the U-shaped relationship between jogging dose and all-cause mortality. Therefore, novice and amateur runners could not only optimize their running training and performance but also their cardiovascular health by following modern training methods used by elite runners.
Please note: Both authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2015 American College of Cardiology Foundation