Sleep quality and sex modify the relationships between trait energy and fatigue on state energy and fatigue

Abstract

The objective of this study was to identify the associations between trait energy and fatigue with state energy fatigue, as well as exploring if these relationships interacted with sex and/ or sleep quality. The study population included a convenience sample of adults and college students (n ranges from 687 to 694). Key measures were state and trait mental and physical energy and fatigue scales, PSQI (a measure of sleep quality), and sex. Multiple regression models included age, polyphenol consumption, POMS scores, physical activity, mental load, and caffeine consumption as covariates. Analyses yielded a strong (r = .65) positive association between each trait and state variable. Overall, several statistically significant interactions were identified. First, the relationship between state and trait physical fatigue was particularly strong for women with high trait scores. There were also interactions with sleep quality. In the case of physical fatigue, poor sleep quality magnified the association between physical fatigue trait and state among those with low trait physical fatigue, while sleep quality did not make a difference for those with high trait physical fatigue. Conversely, in the case of physical energy and mental fatigue, good sleep quality was associated with both higher "highs" and lower "lows" of their respective traits; both interactions were present only among males. Our analyses suggest that sleep quality and sex could influence the effects of trait physical and mental energy and fatigue on state. Findings were more complex than initially assumed, suggesting that the interrelationship between trait and state may be modified by how males and females react and adapt to their trait.

The Effect of Mental Fatigue on Neuromuscular Function is Similar in Young and Older Women

“…Sleep quality and fatigue state were assessed to characterize the young and older participants, as both sleep and fatigue state have been shown to be associated with mental fatigue [20]. The Pittsburgh Sleep Quality Index (PSQI) was used to measure the sleep patterns and quality of sleep in seven domains subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, sleep medication use, and daytime dysfunction.…”

“…Furthermore, as noted above, older women reported greater levels of fatigue than young on the MFI. As state levels of general fatigue are associated with mental fatigue [20], it is possible that these baseline differences influenced the results, although the effect size was low (d = 0.21). However, given this association, we would expect older adults to have a larger change in Likert ratings of fatigue, and reaction time and number of lapses on the PVT, which was not the case.…”

Trait Energy and Fatigue Modify the Effects of Caffeine on Mood, Cognitive and Fine-Motor Task Performance: A Post-Hoc Study

“…For example, until recently, most researchers viewed energy and fatigue on a bipolar continuum (e.g., if an individual is not energetic, then they are fatigued). However, Loy and colleagues [ 9 ] recently provided evidence that energy and fatigue are two distinct moods (e.g., an individual can be energetic and fatigued simultaneously), with multiple studies since showing that feelings of energy and fatigue are distinct yet overlapping constructs [ 10 , 11 , 12 ], with their own mental and physical components [ 13 , 14 ]. Although we are aware of multiple interventions, such as exercise [ 15 ], caffeine [ 16 , 17 ], and sleep [ 18 ], that increase feelings of energy and/or decrease feelings of fatigue, evidence regarding the effectiveness of these interventions is mixed.…”

“…One such potential measure, is trait (long-standing pre-disposition) mental and physical energy and fatigue, a construct only recently reported in the literature [ 13 , 14 ]. While the authors of this study are aware of only one study that examines the effects of trait mental and physical energy and fatigue on moods [ 14 ], that study reports that trait mental and physical energy and fatigue moderates the effects of sleep on state energy and fatigue [ 14 ].…”

“…One such potential measure, is trait (long-standing pre-disposition) mental and physical energy and fatigue, a construct only recently reported in the literature [ 13 , 14 ]. While the authors of this study are aware of only one study that examines the effects of trait mental and physical energy and fatigue on moods [ 14 ], that study reports that trait mental and physical energy and fatigue moderates the effects of sleep on state energy and fatigue [ 14 ]. These findings raise an interesting question about whether trait mental and physical energy and fatigue may also modify the intensity or effects of other interventions (e.g., caffeine) on changes in self-reported mood and/or objective measures of mental energy during the performance of a common mental test battery [ 25 , 26 , 27 , 28 , 29 ] used in nutritional science research.…”