Summary: A new study reports that participating in mentally demanding tasks and experiencing mental exhaustion can have a significant impact on your physical exercise performance.
Source: University of Birmingham
According to a study, people who are subjected to mentally demanding tasks are likely to have a harder time engaging in physical activity.
Researchers from the University of Birmingham’s School of Sport, Exercise and Rehabilitation Sciences measured the effects of cognitive tasks on a group of 16 men and women to examine what happened to their perceptions of physical exertion. Their results showed that mentally exhausted participants had an increased sense of exertion during physical activity.
The results, published in the International Journal of Exercise Physiology and Performance, suggest that addressing the effects of mental fatigue during exercise can help athletes perform better.
Given their findings, the researchers recommend that coaches reduce athletes’ exposure to mentally challenging tasks such as smartphone use before and during training and competitions. Longer term, they should consider “brain endurance training” to increase resilience to mental fatigue.
The lead author Dr. Chris Ring said: “We know that the brain plays a role in physical performance, but the specific effects of mental fatigue are not yet well understood.
“We know that athletes often surf on their smartphones during the breaks between competition and training. All of this requires mental effort and our results strongly suggest that athletes and coaches need to better understand the impact of these activities on overall performance.”
During testing, participants completed a 90-minute mental task of identifying sequences of letters on a screen. They then completed a series of weightlifting repetitions. A control group watched neutral videos before participating in the physical task.
In a second experiment, participants completed a series of resistance training exercises followed by a 20-minute bike time trial. They performed cognitive tasks before and between exercises, with a control group again watching a neutral video. After the cognitive tasks, the participants took an online test to confirm the level of fatigue.
In each experiment, the researchers recorded an increase in perceived exertion—how hard it felt to perform the task—in the mentally exhausted participants. In the second experiment, the researchers also found reduced performance and less distance covered in the mentally exhausted participants in the bike time trial.
The research team has already begun testing the links between mental fatigue and performance in groups of elite athletes in ‘real world’ exercise scenarios.
About this exercise and news from research on mental fatigue
Author: Beck Lockwood
Source: University of Birmingham
Contact: Beck Lockwood – University of Birmingham
Picture: The image is in the public domain
Original research: Closed access.
“Mental Fatigue: The Cost of Cognitive Load in Weightlifting, Resistance Training, and Cycling Performance” by Chris Ring et al. International Journal of Exercise Physiology and Performance
Mental Fatigue: The Cost of Cognitive Load in Weightlifting, Resistance Training, and Cycling Performance
Purpose: Mental Fatigue (MF) can impair physical performance in sport. We tested the hypothesis that cognitive load alone and mixed with standard resistance training would induce MF, increase perceived exertion (RPE) ratings, alter perceptions of weightlifting and exercise, and impair time trial cycling performance.
methods: This two-part study used an within-participant design. In Part 1, after setting leg extension 1 rep (1RM) maximum, 16 participants lifted and held weights at 20%, 40%, 60%, and 80% of 1RM. RPE and electromyography (EMG) were measured for each exercise. During the test sessions, participants completed 90 minutes of cognitive tasks (MF condition) or watched neutral videos (control condition) before lifting the weights.
In Part 2, they completed a submaximal resistance training session consisting of 6 strength training exercises followed by a 20-minute bike time trial. In the MF condition, they completed cognitive tasks before and between strength training exercises. In the control condition, they watched neutral videos. Mood (Brunel Mood Scale), workload (National Aeronautics and Space Administration Task Load Index), MF visual analog scale (MF-VAS), RPE, psychomotor alertness, distance traveled, power output, heart rate, and blood lactate were measured.
Results: In Part 1, the cognitive task increased lift-induced RPE (P = 0.011), increased MF-VAS (P= .002) and altered tuning (P<0.001) compared to control. EMG did not differ between conditions. In part 2, the cognitive tasks increased the RPE (P< 0.001), MF-VAS (P< 0.001) and mental stress (P< 0.001), but reduced wheel time mileage (P= 0.032) and distance (P= 0.023) compared to the control. Heart rate and blood lactate did not differ between conditions.
Diploma:A MF state induced by cognitive load alone or mixed with physical load increased RPE during weightlifting and training and impaired subsequent cycling performance.