Do Cognitive, Physical, and Combined Tasks Induce Similar Levels of Mental Fatigue? Testing the Effects of Different Moderating Variables

The Detrimental Effects of Mental Fatigue on Cognitive and Physical Performance in Older Adults Are Accentuated by Age and Attenuated by Habitual Physical Activity

OBJECTIVE

Our research objectives were to evaluate the extent to which cognitive and physical performance in older adults, when fresh, and when fatigued vary with age and habitual physical activity.

METHODS

We employed experimental study designs, with between- (Study 1: age: 51-64 and 65-80 years and Study 2: habitual physical activity: active and sedentary) and within-participants factors (Study 1: test: before cognitive task and after cognitive task and Study 2: session: fatigue and control and test: before and after cognitive task). In testing sessions, participants performed exercise (6-min walk, 30-s sit stand, and 30-s arm curl) and cognitive (response inhibition and vigilance) tasks before and after a 20-min demanding cognitive task (time load dual back [TLDB] task). In Study 2, participants completed a paced breathing task (control session) as well as the TLDB (fatigue session). Ratings of mental fatigue and exercise-related perceived exertion were obtained.

RESULTS

The 20-min TLDB task elicited a state of mental fatigue. Cognitive and physical performance was worse after than before the TLDB task. These impairments in performance were moderated by age (Study 1) and habitual physical activity (Study 2).

CONCLUSION

The deleterious effects of mental fatigue on cognitive and physical performance were accentuated by aging and attenuated by habitual physical activity.

IMPLICATIONS

Cognitive and/or physical training could mitigate the negative effects of mental fatigue on performance in older adults.

Investigating the impact of perceived mental fatigue on sustained attention performance: a latent growth curve analysis taking social desirability into account

The relationships between perceived fatigue and changes in sustained attention performance during early stages of working on cognitively demanding tasks remain poorly understood. In addition, concerns have been raised that self-ratings of fatigue may be biased by socially desirable response tendencies, potentially confounding the relationship between perceived fatigue and attention performance. In this study, we assessed perceived fatigue briefly before tracking changes in concentration performance, processing speed, and error rates among N = 110 tenth graders, while they completed the d2-R test of sustained attention. By statistically controlling for social desirability, we examined relationships between perceived fatigue and the initial levels and slopes of three latent growth-curves capturing changes in the d2-R test's performance measures. Individuals with higher fatigue exhibited lower concentration performance, a weaker decline in processing speed, and a higher error rate over the course of testing. Post hoc power analyses supported the robustness of our results. Implications for mental fatigue research are discussed.

The effects of different fatigue types on action anticipation and physical performance in high-level volleyball players

This study examined the effects of different fatigue types on action anticipation and physical performance in high-level volleyball players. Twenty-four participants underwent four counterbalanced conditions: 60-min cycling at 60% peak power output, 60-min Stroop task, 60-min cycling at 60% peak power output with Stroop task and 60-min neutral documentary to induce physical fatigue (PF), mental fatigue (MF), dual fatigue (DF) and control group (CG), respectively. Action anticipation (anticipation test and visual search test) and physical performance (countermovement jump, T-test, and spike test) were conducted at baseline, immediately after (Post1), and after 10-min rest (Post2). DF and PF led to significantly lower jump height, T-test completion time, and spiking speed at Post1 and Post2 compared with CG and MF. Compared with PF, DF led to a significant decline in jumping, agility, and spiking performance at Post1 and decreased jumping performance at Post2. MF significantly decreased the reaction time of anticipation test at Post1 compared with CG. Reaction times of visual search test were significantly lower in DF and MF at Post2 compared with CG. It is suggested that PF decreased physical performance, and this is exacerbated in DF. Anticipation performance was affected by MF but not by DF and PF.

Effects of isolated and combined mental and physical fatigue on motor skill and endurance exercise performance

BACKGROUND

Mental fatigue, elicited by cognitive demands, can impair sport and exercise performance. The effects of isolated mental fatigue on performance are well documented but few studies have explored the effects of combined mental and physical fatigue on skilled motor and endurance exercise performance.

OBJECTIVE

This study explored the effects of isolated mental, isolated physical, and combined (mental plus physical) fatigue on skill and exercise task performance.

METHOD

164 athletes were randomly assigned to 1 of 4 groups: mental fatigue, physical fatigue, combined fatigue, control (no fatigue). Mental fatigue was induced by a 15-min time-load dual-back cognitive task. Physical fatigue was induced by a 90-s burpee exercise task. Next, all participants completed a throwing skill task and performed burpee exercises to failure. Objective (brief Psychomotor Vigilance Task, PVT-B) and subjective (self-report) measures of mental fatigue and Ratings of Perceived Exertion were obtained throughout.

RESULTS

The mental fatigue and combined fatigue groups performed the worst on both the throwing and burpee tasks compared with the physical fatigue and control groups. The former reported higher mental fatigue throughout and had worse response accuracy and variation on the end-of-session PVT-B task. The combined fatigue group performed better than the mental fatigue group on the throwing and burpee tasks.

CONCLUSION

A demanding cognitive task induced a state of mental fatigue and impaired skill and endurance performance. Mental fatigue alone was more detrimental than combined fatigue to skill and endurance performance, suggesting that the physical activity manipulation reduced the negative effects of mental fatigue on performance.

Brain Endurance Training Improves and Maintains Chest Press and Squat Jump Performance When Fatigued

ABSTRACT

Díaz-García, J, López-Gajardo, MÁ, Parraca, JA, Batalla, N, López-Rodríguez, R, and Ring, C. Brain endurance training improves and maintains chest press and squat jump performance when fatigued. J Strength Cond Res 38(9): 1568-1575, 2024-Mental fatigue can impair resistance exercise performance. Brain endurance training (BET)-the addition of demanding cognitive tasks to standard exercise training-improves endurance exercise performance more than standard training. Although BET has yet to be evaluated with resistance exercise, it is expected to improve performance, particularly when the performer feels mentally fatigued. The study employed a pretest (week 0), midtest (week 3), posttest (week 6), and follow-up (week 9) design, with subjects randomized to BET ( n = 46) or control (exercise training) ( n = 45) groups. In testing sessions, subjects performed chest press and squat jump exercises to failure before (feeling fresh) and after (feeling tired) a 30-minute cognitively demanding Stroop task. Training comprised 5 BET or control training sessions per week for 6 weeks. In each training session, subjects completed 4 sets of each exercise to failure, with each exercise set preceded by a 3-minute cognitive task (BET) or rest (control). Exercise performance (number of repetitions to failure) and mental fatigue markers were assessed. In pretesting, exercise performance did not differ between the groups. In midtesting and posttesting, BET performed more chest press and squat jump repetitions when fatigued by the 30-minute Stroop than control. The mental fatigue elicited by the Stroop task gradually declined with training in BET compared with control. In conclusion, BET enhanced resistance exercise performance compared with standard training when tested subsequent to a mentally fatiguing cognitive task. These benefits were maintained weeks after training ended. Brain endurance training is an effective method to mitigate the deleterious effects of mental fatigue on resistance exercise performance.

The influence of the perceived requirements of the next match and motivation on the mental fatigue of soccer players

The high cognitive and/or emotional demands of competition can lead to a state of mental fatigue which has shown to be detrimental to soccer performance. However, there is a need to further understand the true mental demands of soccer players. The aim of the present study was to analyze the influence of motivation and the perceived requirements of the next match on mental fatigue perceived by soccer players over the passing of a season. The combined effect of both variables on the perception of mental fatigue, as well as the influence of the time of the season on perceived mental fatigue, were also analyzed. Twenty-six semi-professional Spanish male players (M = 26.31 ± 5.18 years) participated in the present study, conducted during the 2020-2021 season. Perceived mental fatigue and motivation were measured at each training session. The perceived requirements of the next match were also measured in each of the competitive weeks. Linear mixed models were run with R Studio to examine the influence of motivation and the perceived difficulty of the next match on perceived mental fatigue, the combined effect of both variables on perceived mental fatigue, and the influence of the passing of the season on perceived mental fatigue. The results showed a negative and significant influence of motivation on perceived mental fatigue (p < 0.001) and a positive and significant influence of the perceived requirements of the next match on perceived mental fatigue (p < 0.001). Regarding the combined effect, there was a positive and significant effect (p < 0.01) of the perceived difficulty of the next match on the relation between motivation and perceived mental fatigue. A negative influence of season passage on perceived mental fatigue levels was found (p < 0.001). We recommended coaches to consider using the most motivating training tasks when higher next-match requirements are perceived and to be careful with avoidance strategies for mental fatigue, especially at the beginning of the season.

Influence of Scoring Systems on Mental Fatigue, Physical Demands, and Tactical Behavior during Soccer Large-Sided Games

Constraints are common in soccer training to develop physical, technical-tactical, and mental training concurrently. This study examined how different scoring systems influence physical, tactical, and mental demands during large-sided games in soccer. Eighteen youth-elite male (17.39 ± 1.04 y) soccer players completed three 8 vs. 8 large-sided games where the different score systems were i) official score system (OSS; i.e., 1 goal = 1 goal), ii) double the value of the goal-4 min (DVx4; i.e., 1 goal = 1 goal from 0.00 to 7.59 min, and 1 goal = 2 goals from 8.00 to 12.00 min), and iii) double the value of the goal-8 min (DVx8; i.e., 1 goal = 1 goal from 0.00 to 3.59 min, and 1 goal = 2 goals from 4.00 to 12.00 min). Physical demands and tactical behaviors were recorded during tasks using a global positioning system and video camera. Mental fatigue was recorded pre- and post-task using a visual analogue scale. Also, the ratio of perceived exertion and mental load were recorded after tasks were finished. Results reported the highest values of mental and physical demands in DVx4. Mental fatigue increased during all three large-sided games, although this increase was significantly higher in DVx4 compared with OSS (p = 0.006) and DVx8 (p = 0.027). Tactical behavior showed a trend towards more direct play during DVx4, which was less observed during DVx8, and not at all during OSS. In conclusion, changing the scoring system affects physical, tactical, and mental demands.