Setting your training pace: trust your feelings

Grey bars = electronic feedback assisted; black bars = no electronic feedback (only perceived exertion). POrel = average power output per unit of body mass. Apart from segment #5 and #10 (where the feedback cyclists were able to time a late spurt), there were no significant differences between the two groups, either in terms of power or performance.

What was interesting about this piece of research is that it suggested that experienced cyclists were able to use simple bodily and environmental information - eg “How am I feeling and how hard am I breathing?” - to control and adjust their effort levels and achieve comparable time trial performances compared to when feedback was used. Indeed, the researchers concluded by questioning the ‘necessity of the presence of in-race instantaneous task-related feedback via electronic devices for maximizing performance’.

More data

While the finding above - that a wide array of electronic feedback was of no additional benefit to the cyclists’ ability to pace themselves - was completely unexpected, it’s not the only study to reach this conclusion. In a later (2020) piece of research, a team of Aussie researchers investigated whether having task-specific feedback during a 20km time trial enhanced cycling performance, and whether it also helped cyclists to pace themselves more consistently when performing the same task on different days⁽²⁾. Thirty trained, club-level cyclists completed two 20km time trials on two different days under the following conditions:

·        With task-specific feedback (power output, cadence, gear and heart rate) plus elapsed distance

·        No feedback (only perceived exertion and elapsed distance).

During both trials, cycling ergometer variables (power output, cadence, gear) and heart rate were continuously recorded by researchers, although in the no-feedback trial, the cyclists had no access to this data. In both trials, a rating of perceived exertion was also collected every 2km. Once again, the data showed that the cyclists’ performances and pacing behavior were not statistically different between the feedback and the no-feedback trial (ie when the cyclists were relying purely on perceived exertion). In simple terms, the cyclists achieved the same times for the 20km trial regardless of whether they used electronic feedback or relied solely of perceived exertion.

What about runners?

The nature of cycling lends itself to electronic data collection and feedback, which is why much research into pacing, electronic feedback and perceived exertion has focused on cyclists, particularly those with lots of pacing experience. But do these results also apply to runners, and if so, what about less experienced runners? In other words, can runners - even those performing at the recreational level - also use perceived exertion without electronic feedback to pace themselves optimally? To answer this question, we can turn to new research by a team of Belgium scientists⁽³⁾.

Published last month in the ‘Journal of Strength and Conditioning Research’, this study investigated how reliable and reproducible (ie how consistent over a number of different occasions) the use of perceived exertion alone was to set a given running pace. It also compared the use of perceived exertion to regulate pace while running on a track and treadmill, to see if the running surface and environment affected the running pace at a given level of exertion.

What they did

To carry out the study, 55 recreational runners completed six separate 1-km runs under randomized conditions:

·        Four runs at a perceived effort of three out of ten on the 1-10 Borg scale (see figure 2).

·        Two runs at a perceived effort of eight out of ten on the 1-10 Borg scale.

·        At least one run at each of the above levels carried out on both the track and the treadmill in order to compare the different surfaces.

During all of the six runs, the researchers recorded a number of ‘spatiotemporal’ parameters relating the runners’ gaits such as footstrike contact times, stride length and time in flight (when both feet are off the ground). They also measured heart rates for the two exertion levels, and most importantly of all, the pace and pace deviation set by runners at the two exertion levels.

Figure 2: The Borg (modified) 1-10 scale of exertion

The findings

The first key finding was that the self-selected pace the runners used when running at a perceived exertion level of 3 or 8 was characterized by excellent inter-run consistency. Assessed by a measured known as intra-class correlation coefficients, the score of consistency was ranked at 0.93-0.97, which basically meant that the pace the runner chose at a given exertion level was highly reproducible, with minimal variability in measurements between sessions. This consistency was seen regardless of whether the runner ran on the track or treadmill; however, it was also noted that the selected pace when running on the track was even more consistent than when running on the treadmill.

The second finding was that when running on the treadmill, the pace the runners selected was 20% slower at level 3 on the Borg scale and 10% slower at level 8 compared to running at the same exertion level on the track. Just to reiterate, the selected pace on the treadmill was very consistent at both exertion levels – it was just slower than when running on the track. The researchers explained that this was most likely explained by the longer ‘foot to ground’ contact times (+13%), shorter flight times (-35%), and shorter step lengths when running on the treadmill.

Practical implications

In their summing up, the researchers commented that the ‘rate of perceived exertion appears to be a reliable and practical tool for monitoring and prescribing running intensity levels’. In addition, they also pointed out that ‘the slower treadmill speeds at comparable perceived levels could be advantageous for athletes recovering from injury because of the lower biomechanical loading on the lower limb joints’.

In terms of practical application, there are two take-home messages. Firstly, the evidence to date is that perceived exertion is actually a very reliable method indeed of setting a training pace or pacing a race whether you’re cycling or running. And these latest findings suggest that this applies to recreational endurance athletes too – not just those who are highly experienced. Therefore, you shouldn’t feel continuously wedded to electronic feedback and monitoring devices and be a ‘slave to data’. So long as you listen attentively to your body, performing some training sessions or even races without any data feedback is unlikely to harm your performance – indeed, it could actually be a rather liberating experience!

The second message to runners relates to the running environment; if you are using perceived exertion to judge/set a pace, you need to bear in mind that this is running-surface and environment dependent. For example, if you normally train outdoors and set your pace using perceived exertion, don’t be surprised that your pace during a treadmill session at the same exertion level will be noticeably slower. The temptation might be to raise your pace and then wonder why you feel so tired. And while it’s not yet been studied, the same caution is probably needed when cycling on different road surfaces (eg smooth vs. rough tarmac vs. gravel tracks); expect your pace to change for a given effort level. Here are some final tips:

·        Electronic feedback devices can be of enormous value but don’t use them as a substitute for monitoring how you feel (perception of effort, breathing rate, sensations of discomfort etc).

·        Remember that there are always natural short-term variations in performance due to factors like sleep, stress, and (for women) time of the month; when analyzing data from devices, try therefore to look at your longer-term performance trends (eg now compared to 3 months ago) rather than week to week or day to day.

·        All athletes should consider adding in a few ‘data-free’ training sessions per month; not only can it be mentally refreshing, it will help improve your ability to tune in and listen to the feedback from your own body!

References

1.       Front Physiol. 2016 Aug 10;7:348. doi: 10.3389/fphys.2016.00348. eCollection 2016

2.       J Sci Med Sport. 2020 Aug;23(8):758-763

3.       J Strength Cond Res. 2025 Dec 5. doi: 10.1519/JSC.0000000000005293. Online ahead of print