We all know that life needs to go hand and hand with our athletic pursuits. External stressors from school, college, work, family (and a host of other things) play a major role in our response to training. So often as athletes and coaches we do not account for these and are left wondering why – why did that session feel so difficult compared to the weekend? Why did I underperform in this race? On drilling into the finer details we often find out that it was, in fact, mismanaging this external stress along with our training which caused the issue! This study by Filipas, Pollastri and Torre (link here) took this premise to see if there is any truth in it!
Aim of the study?
The study aimed to investigate the effect of a mentally demanding response inhibitory task on time trial performance in sub-elite under 23 cyclists. Or, in layman’s terms, what is the effect of doing a mentally draining task shortly before a training session?
How did they do this?
10 under-23 road cyclists (20±1.2yr / 66.1±7.6kg) voluntarily participated in the study. These athletes were classified as well-trained (VO2max 69.0±4.4 mL-min-1.kg-1, Peak Power 380±39W, > 4 training sessions per week, > 300 km per week, > 3 years of cycling experience). These are some respectable numbers!
A quick interjection on the study design – the authors used a randomised counterbalanced cross-over design. Which means participants were randomly assigned, balanced and each experienced the “intervention” after adequate rest.
The participants visited the lab on four separated occasions which looked a little something like this:
Visit 1: Weight and height + familiarization with the tasks.
Visit 2: A VO2max Test (incremental ramp to exhaustion)
Visits 3 & 4: A performance with and without (control task) a mentally demanding task beforehand.
In terms of the mental and physical tasks themselves the authors used the Stroop Task, psychological questionnaires and a 30-minute cycling time trial during which they measured power output, heart rate, cadence and RPE. Blood lactate and heart rate variability (HRV) was measured in specific increments afterwards (a simple marker of recovery processes).
What was the outcome?
Psychological responses to the Stroop tasks included a decrease in vigour and an increase in fatigue. There was a significantly higher mental demand, effort and frustration also compared with the control. All of this means that the task was enough to illicit some form of mental fatigue.
So, how did this effect time trial performance?
Power output recorded after the Stroop task compared to control condition was lower (overall mean Stroop task: 287 ± 23 W, overall mean control: 295 ± 23 W. Cadence was also lower after the Stroop task compared to the control (100 ± 7 rpm versus 102 ± 6 rpm). There appeared to be no significant differences in RPE or Heart Rate during the time trial.
During the period afterwards where blood lactate and HRV were measured there was no significant difference.
Conclusions and takeaway points
We see a significant difference in both power and cadence after a mentally demanding task. While the decrease in absolute terms is not massive it could be the difference between finishing a specific interval and failing on one! This may highlight he importance of adjusting training intensity after a stressful day or stressful task. It also suggests that mentally demanding tasks should be avoided pre-competition! It would have been interesting to rate the participant’s “enjoyment” of the time trial also to see does mental fatigue induce training monotony symptoms.
Interestingly the authors highlight another study on recreational and elite level athletes1 showing their decrease in performance to be 5.8% and 0.9% respectively. These sub elite athletes had a decrease of 2.8%. It is fair to draw a conclusion here that the more elite you are as an athlete the less “stress” effects your performance.
So, we can conclude that mentally draining tasks do, in-fact, effect performance. Using this information as athletes and coaches we should be aware of stressors in our life and plan for them in training while aiming to limit them during competition.
Featured Paper: Riva, N., La Torre, A., Gallo, G., Pollastri, L., & Filipas, L. (2017). Mental fatigue impairs time-trial performance in under 23 cyclists. In Congresso nazionale SISMES (Vol. 13, No. suppl. 1, pp. S35-S36). Springer.
- Martin K, Staiano W, Menaspà P, Hennessey T, Marcora S, Keegan R, Thompson KG, Martin D, Halson S, Rattray B. Superior inhibitory control and resistance to mental fatigue in professional road cyclists. PloS One. 2016; 11(7)