Matt Chatlaong is currently completing his degree in Exercise Science as he races his bike for the Herbalife p/b Marc Pro – Nature’s Bakery cycling team.  We’re excited to have him on board as an associate coach at Data Driven Athlete!  In this article he shares a few nuggets of wisdom to help you train smarter and ride faster.

Whether from a long day at work, busy time with family, or studying for exams, mental fatigue is a frequent occurrence in life.  As cyclists, mental fatigue not only impacts how we feel, but might also  decrease our performance on the bike.

Psychology and Physiology

It’s important to consider the impact of psychology on exercise performance.  Some research provides evidence for the “central governor model” (CGM) as a means for understanding exercise performance because it takes into account factors that are not purely physiological — such as pacing strategies, and rate of perceived exertion (RPE) [1].  Simultaneously, other researchers argue that the complexity of the integration between psychology and physiology cannot be fully understood by the CGM [2].

Despite sometimes conflicting opinions regarding the CGM, it seems likely that psychological factors play a role significant role in exercise performance, therefore the impact of mental fatigue on exercise performance is worth evaluating.

Training can be confusing. In our free eBook, we’ll show you four ways to use your data and insights from science to ride better than ever.

Mental Fatigue and RPE

Mental Fatigue has been described as “a psychobiological state” that is a result of “prolonged periods of demanding cognitive activity” [3].  Research in this area provides evidence that mental fatigue has a significant effect on RPE:

  • Mental fatigue significantly reduces time to exhaustion during intense exercise (bad).
  • It seems that this negative effect is a result of an increase in reported rate of perceived exertion (RPE), causing an earlier disengagement from the physical task [3].
  • Mentally fatigued people perform less total work in self-paced exercise, likely due to altered RPE [4].

Research also suggests that people in a state of mental fatigue are more likely to quit sooner because the effort feels more difficult.  It’s interesting to note that maximal efforts seem to be relatively unaffected by mental fatigue while extended submaximal seem to be most impacted by the altered RPE [5].

The mechanism(s) behind altered RPE that accompanies mental fatigue are still unclear, but continued research may someday reveal a link between the two.

Practical Applications

­So how can we apply the research into mental fatigue and altered RPE to our lives as athletes?  What these findings demonstrate is that submaximal, extended efforts feel harder during times of greater mental fatigue.

With these expectations in mind, it makes sense to adjust planning/training accordingly in order maintain the greatest balance of beneficial training with the least amount of  motivational impact.  For some athletes this might mean:

  • Deciding to take the day off completely, or switching to an unstructured ride
  • Choosing workouts that require less self-pacing for hard efforts, like group rides or hill rides
  • Using solely RPE to gauge efforts rather than power, knowing that your numbers may be lower than normal, but still executing a workout when training stress is needed
  • Better planning and scheduling of demanding workouts to ensure they land on days containing less “life stress”.


  • Mental fatigue significantly increases RPE in submaximal exercise [3-5].
  • Being sensitive to increased RPE is important to maintain a balance between beneficial training and motivational impact.
  • Changes in workout structure, scheduling, and type might help to also maintain this balance.

Training can be confusing. In our free eBook, we’ll show you four ways to use your data and insights from science to ride better than ever.


1. Noakes, Timothy David. (2011). Time to move beyond a brainless exercise physiology: The evidence for complex regulation of human exercise performance. Applied Physiology, Nutrition, and Metabolism, 36(1), 23.
2. Inzlicht, M., & Marcora, S. M. (2016). The Central Governor Model of Exercise Regulation Teaches Us Precious Little about the Nature of Mental Fatigue and Self-Control Failure. Frontiers in Psychology, 7, 656.
3. Marcora, S., Staiano, W., & Manning, V. (2009). Mental fatigue impairs physical performance in humans. Journal of Applied Physiology (Bethesda, Md. : 1985), 106(3), 857-64.
4. Brownsberger, J., Edwards, A., Crowther, R., & Cottrell, D. (2013). Impact of mental fatigue on self-paced exercise. International journal of sports medicine34(12), 1029-1036.
5. Pageaux, B., Marcora, S. M., Rozand, V., & Lepers, R. (2015). Mental fatigue induced by prolonged self-regulation does not exacerbate central fatigue during subsequent whole-body endurance exercise. Frontiers in Human Neuroscience, 9, 67.