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Sauvet F, Beauchamps V, Cabon P. Sleep Inertia in Aviation. Aerosp Med Hum Perform 2024; 95:206-213. [PMID: 38486319 DOI: 10.3357/amhp.6343.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2024]
Abstract
INTRODUCTION: Sleep inertia is the transition state during which alertness and cognitive performance are temporarily impaired after awakening. Magnitude and time course of sleep inertia are characterized by high individual variability with large differences between the cognitive functions affected. This period of impairment is of concern to pilots, who take sleep or nap periods during on-call work hours or in-flight rest, then need to perform safety-critical tasks soon after waking. This review analyzes literature related to sleep inertia and countermeasures applicable for aviation.METHODS: The large part of scientific literature that focuses on sleep inertia is based on studies in patients with chronic sleep inertia. We analyzed 8 narrative reviews and 64 papers related to acute sleep inertia in healthy subjects.DISCUSSION: Sleep inertia is a multifactorial, complex process, and many different protocols have been conducted, with a low number of subjects, in noncontrolled laboratory designs, with questionnaires or cognitive tests that have not been replicated. Evidence suggests that waking after sleep loss, or from deeper stages of sleep, can exacerbate sleep inertia through complex interactions between awakening and sleep-promoting brain structures. Nevertheless, no meta-analyses are possible and extrapolation to pilots' performances is hypothetical. Studies in real life or simulated operational situations must be conducted to improve the description of the impact of sleep inertia and kinetics on pilots' performances. Taking rest or sleep time remains the main method for pilots to fight against fatigue and related decreases in performance. We propose proactive strategies to mitigate sleep inertia and improve alertness.Sauvet F, Beauchamps V, Cabon P. Sleep inertia in aviation. Aerosp Med Hum Perform. 2024; 95(4):206-213.
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Wang ZJ, Lee HC, Chuang CH, Hsiao FC, Lee SH, Hsu AL, Wu CW. Traces of EEG-fMRI coupling reveals neurovascular dynamics on sleep inertia. Sci Rep 2024; 14:1537. [PMID: 38233587 PMCID: PMC10794702 DOI: 10.1038/s41598-024-51694-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 01/08/2024] [Indexed: 01/19/2024] Open
Abstract
Upon emergence from sleep, individuals experience temporary hypo-vigilance and grogginess known as sleep inertia. During the transient period of vigilance recovery from prior nocturnal sleep, the neurovascular coupling (NVC) may not be static and constant as assumed by previous neuroimaging studies. Stemming from this viewpoint of sleep inertia, this study aims to probe the NVC changes as awakening time prolongs using simultaneous EEG-fMRI. The time-lagged coupling between EEG features of vigilance and BOLD-fMRI signals, in selected regions of interest, was calculated with one pre-sleep and three consecutive post-awakening resting-state measures. We found marginal changes in EEG theta/beta ratio and spectral slope across post-awakening sessions, demonstrating alterations of vigilance during sleep inertia. Time-varying EEG-fMRI coupling as awakening prolonged was evidenced by the changing time lags of the peak correlation between EEG alpha-vigilance and fMRI-thalamus, as well as EEG spectral slope and fMRI-anterior cingulate cortex. This study provides the first evidence of potential dynamicity of NVC occurred in sleep inertia and opens new avenues for non-invasive neuroimaging investigations into the neurophysiological mechanisms underlying brain state transitions.
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Affiliation(s)
- Zhitong John Wang
- Graduate Institute of Mind, Brain and Consciousness, Taipei Medical University, 5 Floor, 301, Yuantong Rd., Zhonghe Dist, New Taipei, 235040, Taiwan
| | - Hsin-Chien Lee
- Department of Psychiatry, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Research Center of Sleep Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Chun-Hsiang Chuang
- Research Center for Education and Mind Sciences, College of Education, National Tsing Hua University, Hsinchu, Taiwan
| | - Fan-Chi Hsiao
- Department of Counseling, Clinical and Industrial/Organizational Psychology, Ming Chuan University, Taoyuan, Taiwan
| | - Shwu-Hua Lee
- Department of Psychiatry, Chang Gung Memorial Hospital at Linkou, 259, Wenhua 1St Rd., Guishan Dist., Taoyuan, 33302, Taiwan
- School of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Ai-Ling Hsu
- Department of Psychiatry, Chang Gung Memorial Hospital at Linkou, 259, Wenhua 1St Rd., Guishan Dist., Taoyuan, 33302, Taiwan.
- Bachelor Program in Artificial Intelligence, Chang Gung University, Taoyuan, Taiwan.
| | - Changwei W Wu
- Graduate Institute of Mind, Brain and Consciousness, Taipei Medical University, 5 Floor, 301, Yuantong Rd., Zhonghe Dist, New Taipei, 235040, Taiwan.
- Research Center of Sleep Medicine, Taipei Medical University Hospital, Taipei, Taiwan.
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Vernau BT, Haider MN, Fleming A, Leddy JJ, Willer BS, Storey EP, Grady MF, Mannix R, Meehan W, Master CL. Exercise-Induced Vision Dysfunction Early After Sport-Related Concussion Is Associated With Persistent Postconcussive Symptoms. Clin J Sport Med 2023:00042752-990000000-00111. [PMID: 37015066 DOI: 10.1097/jsm.0000000000001145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/06/2023]
Abstract
OBJECTIVE The purpose of this study was to determine if exercise-induced vision dysfunction [reduced performance and/or symptom exacerbation on a post-exercise King-Devick (KD) test] in adolescents early after sport-related concussion was associated with increased risk of persistent post-concussive symptoms (PPCS, recovery >28 days). We used exercise as a provocative maneuver before the KD test, hypothesizing that concussed adolescents with exercise-induced vision dysfunction would be more likely to develop PPCS. DESIGN Secondary analysis of data from a multi-center, randomized clinical trial comparing KD test performance before and after the Buffalo Concussion Treadmill Test in adolescents within 10 days of sport-related concussion who were randomized to aerobic exercise or placebo stretching program. SETTING Three university-associated sports medicine clinical programs. PARTICIPANTS Ninety-nine adolescents with sport-related concussion (exercise group: n = 50, 15.3 ± 1 years, 60% M, 22% with PPCS; stretching group: n = 49, 15.9 ± 1 years, 65% M, 35% with PPCS) tested a mean of 6 ± 2 days from injury. INDEPENDENT VARIABLE King-Devick test performed immediately before and 2 minutes after Buffalo Concussion Treadmill Test. MAIN OUTCOME MEASURE Persistent post-concussive symptoms. RESULTS Adolescents who demonstrated exercise-induced vision dysfunction upon initial evaluation developed PPCS at a significantly greater rate when compared with adolescents who did not (71% vs 34%, P < 0.001). Exercise-induced vision dysfunction corresponded to a relative risk of 3.13 for PPCS. CONCLUSIONS Adolescents with exercise-induced vision dysfunction had a 3-fold greater relative risk of developing PPCS than those without exercise-induced vision dysfunction.
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Affiliation(s)
- Brian T Vernau
- Minds Matter Concussion Program, Division of Orthopedics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | | | | | | | - Barry S Willer
- Psychiatry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York
| | - Eileen P Storey
- Minds Matter Concussion Program, Division of Orthopedics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Matthew F Grady
- Minds Matter Concussion Program, Division of Orthopedics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Rebekah Mannix
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts; and
- Harvard Medical School, Boston, Massachusetts
| | - William Meehan
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts; and
- Harvard Medical School, Boston, Massachusetts
| | - Christina L Master
- Minds Matter Concussion Program, Division of Orthopedics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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Physical and psychological health in intern paramedics commencing shift work: Protocol for an exploratory longitudinal study. PLoS One 2022; 17:e0273113. [PMID: 36454797 PMCID: PMC9714933 DOI: 10.1371/journal.pone.0273113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 09/09/2022] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Paramedics are routinely exposed to shift work. Existing research shows that shift work exposure is associated with adverse mental and physical health outcomes. However, the current understanding of the impact of commencing shift work in a paramedic role on health is limited. This can be addressed by recruiting new paramedics before they commence shift work, and conducting regular follow-ups of potential biological, psychological and social changes. The present study aimed to examine changes in biological, psychological and social factors relative to pre-shift work baseline in a cohort of paramedics commencing intern employment with an Australian ambulance service. METHOD AND ANALYSIS This observational, mixed-methods, longitudinal study aims to recruit 40 interns from one Australian ambulance service. Data collection will occur at baseline (standard day schedule for initial training), and subsequently at three months, six months, nine months and twelve months, to measure biological, psychological and social changes relative to baseline measurements. Changes in cardiometabolic markers (cholesterol, triglycerides, fasting glucose), microbiome (self-collected stool samples), sleep and physical activity (actigraphy) will be measured. Interns will also complete a battery of self-report questionnaires, sleep diaries and qualitative interviews to explore various psychological and social variables over time. Statistical analyses will be conducted using mixed effects regression, specifying a random effect of subject on the intercept, allowing participants to vary according to individual baseline levels, as well as tracking progress over time, appropriately accounting for serial correlation. Qualitative study components will be analysed via coding and thematic analysis procedures. DISCUSSION The present study protocol is a comprehensive outline of the observational study planned. The study will allow for greater knowledge of any changes in biological, psychological and social factors during a 12-month transition to shift work. The findings from the proposed study will have implications for the development of strategies to support early-career shift workers.
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Mattingly SM, Martinez G, Young J, Cain MK, Striegel A. Snoozing: an examination of a common method of waking. Sleep 2022; 45:6661272. [PMID: 35951011 PMCID: PMC9548674 DOI: 10.1093/sleep/zsac184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 06/30/2022] [Indexed: 11/16/2022] Open
Abstract
Study Objectives Snoozing was defined as using multiple alarms to accomplish waking, and considered as a method of sleep inertia reduction that utilizes the stress system. Surveys measured snoozing behavior including who, when, how, and why snoozing occurs. In addition, the physiological effects of snoozing on sleep were examined via wearable sleep staging and heart rate (HR) activity, both over a long time scale, and on the days that it occurs. We aimed to establish snoozing as a construct in need of additional study. Methods A novel survey examined snoozing prevalence, how snoozing was accomplished, and explored possible contributors and motivators of snoozing behavior in 450 participants. Trait- and day-level surveys were combined with wearable data to determine if snoozers sleep differently than nonsnoozers, and how snoozers and nonsnoozers differ in other areas, such as personality. Results 57% of participants snoozed. Being female, younger, having fewer steps, having lower conscientiousness, having more disturbed sleep, and being a more evening chronotype increased the likelihood of being a snoozer. Snoozers had elevated resting HR and showed lighter sleep before waking. Snoozers did not sleep less than nonsnoozers nor did they feel more sleepiness or nap more often. Conclusions Snoozing is a common behavior associated with changes in sleep physiology before waking, both in a trait- and state-dependent manner, and is influenced by demographic and behavioral traits. Additional research is needed, especially in detailing the physiology of snoozing, its impact on health, and its interactions with observational studies of sleep.
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Affiliation(s)
- Stephen M Mattingly
- Department of Computer Science and Engineering, University of Notre Dame , Notre Dame, IN , USA
| | - Gonzalo Martinez
- Department of Computer Science and Engineering, University of Notre Dame , Notre Dame, IN , USA
| | - Jessica Young
- Lucy Family Institute for Data and Society, University of Notre Dame , Notre Dame, IN , USA
| | | | - Aaron Striegel
- Department of Computer Science and Engineering, University of Notre Dame , Notre Dame, IN , USA
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C Gupta C, Dominiak M, Kovac K, C Reynolds A, A Ferguson S, J Hilditch C, Sprajcer M, E Vincent G. On-call work and sleep: the importance of switching on during a callout and switching off after a call. INDUSTRIAL HEALTH 2022; 60:91-96. [PMID: 34690251 PMCID: PMC8980688 DOI: 10.2486/indhealth.2021-0124] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/23/2021] [Indexed: 06/13/2023]
Abstract
Due to the unpredictable nature of working time arrangements, on-call workers experience regular disruption to sleep, particularly if woken by calls. Sleep disruption can impact long term physical and mental health, next day performance, and importantly, performance immediately after waking. To reduce the impact of performance impairments upon waking (i.e., reducing sleep inertia), research has investigated strategies to promote alertness (e.g., bright light, caffeine, and exercise). This review puts forth on-call workers who are likely to return to sleep after a call, it is also important to consider the impact of these sleep inertia countermeasures on subsequent sleep. Future research should build on the preliminary evidence base for sleep inertia countermeasures by examining the impact on subsequent sleep. This research is key for both supporting alertness and performance during a call ("switching on") and for allowing the on-call worker to return to sleep after a call ("switching off").
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Affiliation(s)
- Charlotte C Gupta
- Central Queensland University, Appleton Institute for Behavioural Science, Australia
| | - Michelle Dominiak
- Central Queensland University, Appleton Institute for Behavioural Science, Australia
| | - Katya Kovac
- Central Queensland University, Appleton Institute for Behavioural Science, Australia
| | - Amy C Reynolds
- Flinders Health and Medical Research Institute (Sleep Health), Flinders University, Australia
| | - Sally A Ferguson
- Central Queensland University, Appleton Institute for Behavioural Science, Australia
| | - Cassie J Hilditch
- San José State University, Fatigue Countermeasures Laboratory, Department of Psychology, USA
| | - Madeline Sprajcer
- Central Queensland University, Appleton Institute for Behavioural Science, Australia
| | - Grace E Vincent
- Central Queensland University, Appleton Institute for Behavioural Science, Australia
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Kovac K, Vincent GE, Paterson JL, Ferguson SA. "I Want to Be Safe and Not Still Half Asleep": Exploring Practical Countermeasures to Manage the Risk of Sleep Inertia for Emergency Service Personnel Using a Mixed Methods Approach. Nat Sci Sleep 2022; 14:1493-1510. [PMID: 36052102 PMCID: PMC9427208 DOI: 10.2147/nss.s370488] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 07/08/2022] [Indexed: 11/23/2022] Open
Abstract
PURPOSE The aim of this exploratory cross-sectional mixed methods study was to determine 1) whether sleep inertia, the temporary state of impaired vigilance performance upon waking, is perceived to be a concern by emergency service personnel, 2) what strategies are currently used by emergency service workplaces to manage sleep inertia, 3) the barriers to implementing reactive sleep inertia countermeasures, and 4) what strategies personnel suggest to manage sleep inertia. PARTICIPANTS AND METHODS A sample (n = 92) of employed and volunteer Australian emergency service personnel (fire and rescue, ambulance, police, state-based rescue and recovery personnel) completed an online survey. Data collected included demographic variables and work context, experiences of sleep inertia in the emergency role, barriers to sleep inertia countermeasures, and existing workplace sleep inertia countermeasures and recommendations. Quantitative data were analysed using descriptive statistics, and qualitative data were thematically analysed. RESULTS Approximately 67% of participants expressed concern about sleep inertia when responding in their emergency role. Despite this, there were few strategies to manage sleep inertia in the workplace. One major barrier identified was a lack of time in being able to implement sleep inertia countermeasures. Fatigue management strategies, such as reducing on-call periods, and operational changes, such as screening calls to reduce false alarms, were suggested by participants as potential strategies to manage sleep inertia. CONCLUSION Sleep inertia is a concern for emergency service personnel and thus more research is required to determine effective sleep inertia management strategies to reduce the risks associated with sleep inertia and improve personnel safety and those in their care. In addition, future studies could investigate strategies to integrate reactive sleep inertia countermeasures into the emergency response procedure.
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Affiliation(s)
- Katya Kovac
- School of Health, Medical and Applied Sciences, Appleton Institute, Central Queensland University, Wayville, SA, Australia
| | - Grace E Vincent
- School of Health, Medical and Applied Sciences, Appleton Institute, Central Queensland University, Wayville, SA, Australia
| | - Jessica L Paterson
- Flinders Institute of Mental Health and Wellbeing, College of Education, Psychology and Social Work, Flinders University, Bedford Park, SA, Australia
| | - Sally A Ferguson
- School of Health, Medical and Applied Sciences, Appleton Institute, Central Queensland University, Wayville, SA, Australia
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Kovac K, Vincent GE, Paterson JL, Reynolds A, Aisbett B, Hilditch CJ, Ferguson SA. The impact of a short burst of exercise on sleep inertia. Physiol Behav 2021; 242:113617. [PMID: 34606883 DOI: 10.1016/j.physbeh.2021.113617] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/16/2021] [Accepted: 09/29/2021] [Indexed: 11/18/2022]
Abstract
STUDY OBJECTIVES Determine whether 30 s (s) of exercise performed upon waking can reduce sleep inertia and accelerate an increase in the cortisol awakening response (CAR) and core body temperature (CBT), compared to when sedentary. METHODS Fifteen participants (mean age ± SD, 25.9 ± 5.9 years; six females) completed a counterbalanced, repeated measures, in-laboratory study involving three single experimental nights, each separated by a four-night recovery period. Participants were woken following a 2-h nap (2400-0200) and completed a cycling bout of high-intensity (30-s sprint), low-intensity (30 s at 60% maximum heart rate), or no exercise (sedentary). Sleep inertia testing (eight batteries, 15-min intervals) began immediately following and included measures of subjective sleepiness (Karolinska Sleepiness Scale) and cognitive performance tasks (psychomotor vigilance, serial addition and subtraction, and spatial configuration). CBT was measured continuously via an ingestible telemetric capsule. The CAR was determined using salivary cortisol samples collected at 0, 30 and 45 min post-waking. Data were analysed using mixed effects analysis of variance. RESULTS There was no difference in cognitive performance or CBT between conditions. Participants felt less sleepy in the high-intensity condition, followed by the low-intensity and sedentary conditions (p = .003). The CAR was greatest in the high-intensity condition, followed by the sedentary condition, and low-intensity condition (p < 0.001), with no differences between the low-intensity and sedentary conditions. CONCLUSIONS Those who exercise upon waking should be aware that while they may feel more alert, they may not be performing better than if they had not exercised. Future research should investigate whether exercise of different duration or timing may impact sleep inertia.
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Affiliation(s)
- Katya Kovac
- Central Queensland University, Appleton Institute, School of Health, Medical and Applied Sciences, Wayville, Adelaide, Australia.
| | - Grace E Vincent
- Central Queensland University, Appleton Institute, School of Health, Medical and Applied Sciences, Wayville, Adelaide, Australia
| | - Jessica L Paterson
- Central Queensland University, Appleton Institute, School of Health, Medical and Applied Sciences, Wayville, Adelaide, Australia
| | - Amy Reynolds
- Central Queensland University, Appleton Institute, School of Health, Medical and Applied Sciences, Wayville, Adelaide, Australia
| | - Brad Aisbett
- Deakin University, Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Geelong, Victoria, Australia
| | - Cassie J Hilditch
- Fatigue Countermeasures Laboratory, San José State University, San José, CA, USA
| | - Sally A Ferguson
- Central Queensland University, Appleton Institute, School of Health, Medical and Applied Sciences, Wayville, Adelaide, Australia
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Sela Y, Hoekstra MM, Franken P. Sub-minute prediction of brain temperature based on sleep-wake state in the mouse. eLife 2021; 10:62073. [PMID: 33683202 PMCID: PMC7939547 DOI: 10.7554/elife.62073] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 02/17/2021] [Indexed: 12/11/2022] Open
Abstract
Although brain temperature has neurobiological and clinical importance, it remains unclear which factors contribute to its daily dynamics and to what extent. Using a statistical approach, we previously demonstrated that hourly brain temperature values co-varied strongly with time spent awake (Hoekstra et al., 2019). Here we develop and make available a mathematical tool to simulate and predict cortical temperature in mice based on a 4-s sleep-wake sequence. Our model estimated cortical temperature with remarkable precision and accounted for 91% of the variance based on three factors: sleep-wake sequence, time-of-day ('circadian'), and a novel 'prior wake prevalence' factor, contributing with 74%, 9%, and 43%, respectively (including shared variance). We applied these optimized parameters to an independent cohort of mice and predicted cortical temperature with similar accuracy. This model confirms the profound influence of sleep-wake state on brain temperature, and can be harnessed to differentiate between thermoregulatory and sleep-wake-driven effects in experiments affecting both.
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Affiliation(s)
- Yaniv Sela
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Marieke Mb Hoekstra
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Paul Franken
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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Lastella M, Halson SL, Vitale JA, Memon AR, Vincent GE. To Nap or Not to Nap? A Systematic Review Evaluating Napping Behavior in Athletes and the Impact on Various Measures of Athletic Performance. Nat Sci Sleep 2021; 13:841-862. [PMID: 34194254 PMCID: PMC8238550 DOI: 10.2147/nss.s315556] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 05/22/2021] [Indexed: 12/13/2022] Open
Abstract
PURPOSE The objective of this systematic review was to 1) determine how studies evaluated napping behavior in athletes (frequency, duration, timing and measurement); 2) explore how napping impacted physical performance, cognitive performance, perceptual measures (eg, fatigue, muscle soreness, sleepiness and alertness), psychological state and night-time sleep in athletes. METHODS Five bibliographic databases were searched from database inception to 11 August 2020. Observational and experimental studies comprising able-bodied athletes (mean age ≥12 years), published in English, in peer-reviewed journal papers were included. The Downs and Black Quality Assessment Checklist was used for quality appraisal. RESULTS Thirty-seven studies were identified of moderate quality. Most studies did not include consistent information regarding nap frequency, duration, and timing. Napping may be beneficial for a range of outcomes that benefit athletes (eg, physical and cognitive performance, perceptual measures, psychological state and night-time sleep). In addition, napping presents athletes with the opportunity to supplement their night-time sleep without compromising sleep quality. CONCLUSION Athletes may consider napping between 20 to 90 min in duration and between 13:00 and 16:00 hours. Finally, athletes should allow 30 min to reduce sleep inertia prior to training or competition to obtain better performance outcomes. Future studies should include comprehensive recordings of nap duration and quality, and consider using sleep over a 24 hour period (daytime naps and night-time sleep period), specifically using objective methods of sleep assessment (eg, polysomnography/actigraphy).
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Affiliation(s)
- Michele Lastella
- Appleton Institute for Behavioural Science, Central Queensland University, Adelaide, Australia
| | - Shona L Halson
- School of Behavioural and Health Sciences, Australian Catholic University, Brisbane, Australia
| | - Jacopo A Vitale
- Laboratory of Movement and Sport Science, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
| | - Aamir R Memon
- Institute of Physiotherapy & Rehabilitation Sciences, Peoples University of Medical & Health Sciences for Women, Nawabshah, Shaheed Benazirabad, Pakistan
| | - Grace E Vincent
- Appleton Institute for Behavioural Science, Central Queensland University, Adelaide, Australia
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Kovac K, Vincent GE, Paterson JL, Aisbett B, Reynolds AC, Ferguson SA. Can an increase in noradrenaline induced by brief exercise counteract sleep inertia? Chronobiol Int 2020; 37:1474-1478. [PMID: 32946288 DOI: 10.1080/07420528.2020.1803900] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Emergency responders often credit 'adrenaline' (i.e. sympathetic activity) as the reason they respond quickly upon waking, unimpaired by sleep inertia. Movement upon waking may promote sympathetic activity in this population. This pilot study (n = 4 healthy males) tested the effects of a 30 s exercise bout (maximal sprint) upon waking during the night (02:00 h) on sympathetic activity and sleep inertia. When compared to sedentary conditions, exercise reduced subjective sleepiness levels and elicited a temporary increase in sympathetic activity, measured by plasma noradrenaline levels. These findings provide preliminary support for exercise as a potential sleep inertia countermeasure.
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Affiliation(s)
- Katya Kovac
- Appleton Institute, School of Health, Medical and Applied Sciences, Central Queensland University, Wayville, Adelaide, Australia
| | - Grace E Vincent
- Appleton Institute, School of Health, Medical and Applied Sciences, Central Queensland University, Wayville, Adelaide, Australia
| | - Jessica L Paterson
- Appleton Institute, School of Health, Medical and Applied Sciences, Central Queensland University, Wayville, Adelaide, Australia
| | - Brad Aisbett
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Amy C Reynolds
- Appleton Institute, School of Health, Medical and Applied Sciences, Central Queensland University, Wayville, Adelaide, Australia
| | - Sally A Ferguson
- Appleton Institute, School of Health, Medical and Applied Sciences, Central Queensland University, Wayville, Adelaide, Australia
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12
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Dawson D, Ferguson SA, Vincent GE. Safety implications of fatigue and sleep inertia for emergency services personnel. Sleep Med Rev 2020; 55:101386. [PMID: 33027747 DOI: 10.1016/j.smrv.2020.101386] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 07/12/2020] [Accepted: 07/13/2020] [Indexed: 12/31/2022]
Abstract
Emergency services present a unique operational environment for the management of fatigue and sleep inertia. Communities request and often expect the provision of emergency services on a 24/7/365 basis. This can result in highly variable workloads and/or significant need for on-demand or on-call working time arrangements. In turn, the management of fatigue-related risk requires a different approach than in other more predictable shift working sectors (e.g., mining and manufacturing). The aim of this review is to provide a comprehensive overview of fatigue risk management that is accessible to regulators, policy makers and organisations in the emergency services sector. The review outlines the unique fatigue challenges in the emergency services sector, examines the current scientific and policy consensus around managing fatigue and sleep inertia, and finally discusses strategies that emergency services organisations can use to minimise the risks associated with fatigue and sleep inertia.
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Affiliation(s)
- Drew Dawson
- Central Queensland University, Appleton Institute, Adelaide, South Australia, Australia.
| | - Sally A Ferguson
- Central Queensland University, Appleton Institute, Adelaide, South Australia, Australia
| | - Grace E Vincent
- Central Queensland University, Appleton Institute, Adelaide, South Australia, Australia
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13
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Sleep Inertia Countermeasures in Automated Driving: A Concept of Cognitive Stimulation. INFORMATION 2020. [DOI: 10.3390/info11070342] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
When highly automated driving is realized, the role of the driver will change dramatically. Drivers will even be able to sleep during the drive. However, when awaking from sleep, drivers often experience sleep inertia, meaning they are feeling groggy and are impaired in their driving performance―which can be an issue with the concept of dual-mode vehicles that allow both manual and automated driving. Proactive methods to avoid sleep inertia like the widely applied ‘NASA nap’ are not immediately practicable in automated driving. Therefore, a reactive countermeasure, the sleep inertia counter-procedure for drivers (SICD), has been developed with the aim to activate and motivate the driver as well as to measure the driver’s alertness level. The SICD is evaluated in a study with N = 21 drivers in a level highly automation driving simulator. The SICD was able to activate the driver after sleep and was perceived as “assisting” by the drivers. It was not capable of measuring the driver’s alertness level. The interpretation of the findings is limited due to a lack of a comparative baseline condition. Future research is needed on direct comparisons of different countermeasures to sleep inertia that are effective and accepted by drivers.
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Dominiak M, Kovac K, Reynolds AC, Ferguson SA, Vincent GE. The effect of a short burst of exercise during the night on subsequent sleep. J Sleep Res 2020; 30:e13077. [PMID: 32495463 DOI: 10.1111/jsr.13077] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 03/12/2020] [Accepted: 04/27/2020] [Indexed: 11/29/2022]
Abstract
When on-call workers wake during the night to perform work duties, they may experience reduced alertness and impaired performance as a result of sleep inertia. After performing their duties, on-call workers may have the opportunity to return to sleep. Thus, it is important that sleep inertia countermeasures do not affect subsequent sleep. Exercise may be a suitable countermeasure; however, the impact on subsequent sleep is untested. Healthy participants (n = 15) completed three conditions in a counterbalanced order: sedentary, low-intensity exercise or high-intensity exercise, performed for 2 min upon awakening. Sleep was recorded 2 hr later using polysomnography, the Karolinska Sleepiness Scale was administered to measure subjective sleepiness, and core body temperature was measured continuously. Results indicate there was no effect of condition on most sleep variables; however, three variables had small differences, with longer total sleep time (p = .006), higher sleep efficiency (p = .006) and shorter N3 latency (p < .001) in the low-intensity exercise condition. There was no difference in subjective sleepiness (p = .124) or core body temperature (p = .216) 90 min after the exercise intervention. These results indicate that using a short burst of exercise to counteract sleep inertia when woken during the night may be a suitable countermeasure for on-call workers who not only need to be alert upon waking but also need quality sleep when returning to bed. Future research could include participants of other ages and health statuses to investigate whether the results are generalizable.
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Affiliation(s)
- Michelle Dominiak
- Appleton Institute, Central Queensland University, Adelaide, SA, Australia
| | - Katya Kovac
- Appleton Institute, Central Queensland University, Adelaide, SA, Australia
| | - Amy C Reynolds
- Appleton Institute, Central Queensland University, Adelaide, SA, Australia
| | - Sally A Ferguson
- Appleton Institute, Central Queensland University, Adelaide, SA, Australia
| | - Grace E Vincent
- Appleton Institute, Central Queensland University, Adelaide, SA, Australia
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