The Sleep Parameters of Olympic Athletes: Characteristics and Assessment Instruments.

This systematic review aims to identify the sleep parameters of Olympic athletes and the instruments used to assess and monitor the sleep of these athletes. The search was conducted until February 2023 and was performed in PubMed, Web of Science, and Scopus databases. This systematic review has included studies that investigated at least one of the following sleep parameters: total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE), awakenings after sleep onset (WASO), quality of sleep, daytime sleepiness, and chronotype; the participants were Olympic athletes. The search returned a total of 280 studies. After screening based on exclusion and inclusion criteria, 11 studies were included. The main results demonstrate that Olympic athletes have TST of 06:10 h, SE of 84%, SOL of 28 min, and WASO of 49 min. The most predominant chronotype is indifferent; over half of the athletes have poor sleep quality and complaints. Furthermore, actigraphy was the most used method to assess sleep. It is concluded that Olympic athletes have TST, SE, and WASO poor than the recommended values. In addition, sleep complaints and poor sleep quality were also observed. Among the objective sleep assessment methods, actigraphy was the method most frequently used in this population.

Portable PSG for sleep stage monitoring in sports: Assessment of SOMNOwatch plus EEG.

Current sport-scientific studies mostly neglect the assessment of sleep architecture, although the distribution of different sleep stages is considered an essential component influencing an athlete's recovery and performance capabilities. A mobile, self-applied tool like the SOMNOwatch plus EEG might serve as an economical and time-friendly alternative to activity-based devices. However, self-application of SOMNOwatch plus EEG has not been validated against conventional polysomnography (PSG) yet. For evaluation purposes, 25 participants (15 female, 10 male; M age = 22.92 ± 2.03 years) slept in a sleep laboratory on two consecutive nights wearing both, conventional PSG and SOMNOwatch plus EEG electrodes. Sleep parameters and sleep stages were compared using paired t-tests and Bland-Altman plots. No significant differences were found between the recordings for Sleep Onset Latency, stages N1 to N3 as well as Rapid Eye Movement stage. Significant differences (Bias [95%-confidence interval]) were present between Total Sleep Time (9.95 min [-29.18, 49.08], d = 0.14), Total Wake Time (-13.12 min [-47.25, 23.85], d = -0.28), Wake after Sleep Onset (-11.70 min [-47.25, 23.85], d = -0.34) and Sleep Efficiency (2.18% [-7.98, 12.34], d = 0.02) with small effect sizes. Overall, SOMNOwatch plus EEG can be considered a valid and practical self-applied method for the examination of sleep. In sport-scientific research, it is a promising tool to assess sleep architecture in athletes; nonetheless, it cannot replace in-lab PSG for all clinical or scientific purposes.

Validity of two retrospective questionnaire versions of the Consensus Sleep Diary: the whole week and split week Self-Assessment of Sleep Surveys.

OBJECTIVE/BACKGROUND: Prospective, daily sleep diaries are the gold standard for assessing subjective sleep but are not always feasible for cross-sectional or epidemiological studies. The current study examined psychometric properties of two retrospective questionnaire versions of the Consensus Sleep Diary. PARTICIPANTS/METHODS: College students (N = 131, mean age = 19.39 ± 1.65; 73% female) completed seven days of prospective sleep diaries then were randomly assigned to complete either the Self-Assessment of Sleep Survey (SASS), which assessed past week sleep (n = 70), or the SASS-Split (SASS-Y), which assessed weekday/weekend sleep separately (n = 61). Participants also completed psychosocial/sleep questionnaires including the Pittsburgh Sleep Quality Index (PSQI). Sleep parameters derived from SASS, SASS-Y, PSQI, and sleep diaries were assessed via Bland Altman plots, limits of agreement, mean differences, and correlations. RESULTS: SASS-Y demonstrated stronger correlations with prospective sleep diaries and slightly less biased estimates (r = 0.51 to 0.85, α = -0.43 to 1.70) compared to SASS (r = 0.29 to 0.84, α = -1.63 to 2.33) for terminal wakefulness (TWAK), sleep onset latency (SOL), sleep efficiency (SE), and quality (QUAL). SASS resulted in slightly less bias for total sleep time (TST) and wake after sleep onset (WASO) (α = -0.65 and 0.93, respectively) compared to SASS-Y (α = 14.90 and 1.05, respectively). SASS and SASS-Y demonstrated greater convergence with sleep diary than PSQI. CONCLUSIONS: Results demonstrated good psychometric properties for the SASS and SASS-Y. When prospective sleep diaries are not feasible, the SASS and SASS-Y are acceptable substitutes to retrospectively estimate sleep parameters. Retrospective estimation of sleep parameters separately for weekdays/weekends may offer advantages compared to whole week estimation.

Infant nocturnal wakefulness: a longitudinal study comparing three sleep assessment methods.

Study Objectives: To examine the convergence between actigraphy, sleep diaries, and the Brief Infant Sleep Questionnaire (BISQ) in the assessment of infant nocturnal wakefulness (i.e. minutes awake after sleep onset [WASO] and number of night-wakings [NW]) in the context of a longitudinal study. Methods: The sample included 226 families, who were recruited during pregnancy. Data were collected at 3, 6, 12, and 18 months postpartum. Infants' sleep was monitored at home for five nights using actigraphy, sleep diaries, and the BISQ. Outcome measures included WASO and NW, as well as sleep latency, sleep duration, and sleep onset. Results: Trajectory analyses demonstrated that all three methods showed declines in NW and WASO from 3 to 18 months. Statistically significant correlations were found between the three methods at all assessment points for all sleep variables. However, agreement rates (using Krippendorff's α and Bland-Altman analyses) between actigraphy and parental reports were poor. For NW, agreement between actigraphy and parental reports at 18 months was lower than that at 3 and 6 months. Diaries and BISQ showed satisfactory agreement for sleep latency. Conclusions: Although the three methods' measures of infant nocturnal wakefulness are significantly correlated during infancy, absolute agreement between these methods is poor overall. The growing disagreement between actigraphy and parental reports (in NW) across development probably suggests that parents become less aware of infants' awakenings, due to the increasing ability of infants to self-soothe. Using both objective and subjective assessment methods seems especially important after the age of 6 months.