Mental Fatigue Impairs Postural Stability in Older Adults

The Influence of Mental Fatigue on Physical Performance and Its Relationship with Rating Perceived Effort and Enjoyment in Older Adults

The study investigated the influence of mental fatigue on older people's enjoyment during a series of physical exercises. Using a randomized cross-over design, participants (n = 35) completed a 6-minute walking test - 6MWT, a Timed Up and Go-TUG test and three sets of knee extension exercise (first set: KE1, second set: KE2, third set: KE3) under two experimental conditions (control or mental fatigue). The Nonparametric Analysis of Longitudinal Data in Factorial Experiments was used to compare the number of repetitions performed during three sets of resistance exercise between conditions. The same analysis method was applied to compare the perception of effort and enjoyment across five moments (Post-6MWT, Post-TUG, Post-KE1, Post-KE2, Post-KE3) and two conditions and the Visual Analogue Scales (VAS) across four moments (baseline, Pre-6MWT, Pre-TUG, Pre-KE) and two conditions. Mental fatigue did not affect the physical function, perception of effort and enjoyment of exercise in older people. Participants, however, reported higher enjoyment for walking and dynamic balance compared to strength exercise. Mental fatigue had no effect on the physical function, perception of effort and enjoyment of exercise of older people. Participants presented a higher enjoyment for walking and dynamic balance compared to strength exercise. Given the importance of resistance exercises for health, clinicians should prioritize resources to education programs emphasizing the benefits of resistance exercise in both short- and long-term health. Including social interaction opportunities in physical exercise programs and prescribing activities appropriate to participants' ability levels could enhance engagement and adherence.

Brain endurance training improves sedentary older adults' cognitive and physical performance when fresh and fatigued

OBJECTIVES

Cognitive and physical performance is impaired by aging and fatigue. Cognitive and exercise training may mitigate such impairments. Accordingly, we investigated the effect of Brain Endurance Training (BET) - combined cognitive and exercise training - on cognitive and physical performance when fresh and fatigued in older adults.

DESIGN

Twenty-four healthy sedentary women (65-78 years) were randomly allocated to one of three training groups: BET, exercise training, and control (no training). The BET and exercise training groups completed the same physical training protocol comprising three 45-min exercise sessions (20-min resistance exercise plus 25-min endurance exercise) per week for eight weeks. The BET group completed a 20-min cognitive task prior to exercise tasks. Cognitive (tasks: psychomotor vigilance, Stroop) and physical (tests: walk, chair-stand, arm curl) performance was tested when fresh and fatigued (before and after a 30-min cognitive task) at weeks 0 (pre-test), 4 (mid-test), 8 (post-test), and 12 (follow-up test).

RESULTS

Cognitive and physical and performance was generally superior when fresh and fatigued at mid-test and post-test for both BET and exercise training groups compared to the control group. The BET group outperformed the exercise group when fatigued at mid-test and post-test both cognitively (always) and physically (sometimes). The pre-to-post changes in cognitive performance when fresh and fatigued averaged 3.7 % and 7.8 % for BET, 3.6 % and 4.5 % for exercise, and -0.4 % and 0.3 % for control groups. The corresponding changes in physical performance averaged 16.5 % and 29.9 % for BET, 13.8 % and 22.4 % for exercise, and 10.8 % and 7.1 % for control groups.

CONCLUSION

These findings show that BET can improve cognitive and physical performance in older adults.

Age and Type of Task-Based Impact of Mental Fatigue on Balance: Systematic Review and Meta-Analysis

The role of cognition in balance control suggests that mental fatigue may negatively affect balance. However, cognitive involvement in balance control varies with the type or difficulty of the balance task and age. Steady-state balance tasks, such as quiet standing, are well-learned tasks executed automatically through reflex activities controlled by the brainstem and spinal cord. In contrast, novel, and challenging balance tasks, such as proactively controlling balance while walking over rugged terrain or reacting to unexpected external perturbations, may require cognitive processing. Furthermore, individuals with preexisting balance impairments due to aging or pathology may rely on cognitive processes to control balance in most circumstances. This systematic review and meta-analysis investigated the effect of mental fatigue on different types of balance control tasks in young and older adults. A literature search was conducted in seven electronic databases and 12 studies met eligibility criteria. The results indicated that mental fatigue had a negative impact on both proactive (under increased cognitive load) and reactive balance in young adults. In older adults, mental fatigue affected steady-state and proactive balance. Therefore, mentally fatigued older individuals may be at increased risk of a loss of balance during steady-state balance task compared to their younger counterparts.