The Limitations of Using the Pittsburgh Sleep Quality Index to Assess Athletes' Sleep Quality: Evidence from Reliability and Validity in Chinese Professional Athletes.

Purpose: This study aimed to assess the structural validity of the Chinese version of the Pittsburgh Sleep Quality Index (PSQI) among Chinese professional athletes and examine its test-retest reliability and convergent validity across different timeframes. Methods: 581 Chinese professional athletes participated. Exploratory and confirmatory factor analyses were conducted on the Chinese version of the PSQI. Test-retest reliability was assessed over 2 weeks, 1 week, and 2-3 days within a 1-month timeframe. Additional reliability analysis over a 2-day interval was conducted within a 1-week timeframe. Convergent validity was assessed using Chinese versions of the Insomnia Severity Index (ISI), the Athlete Sleep Screening Questionnaire (ASSQ), and actigraphy. A 1-month tracking was conducted, with weekly completion of the PSQI using a one-week timeframe, supplemented by assessments in the second and fourth week using two-week and one-month timeframes. Relationships between weekly results and those over two weeks and one month examined, along with convergent validity, using sleep diary and actigraphy. Results: The PSQI exhibited a two-factor structure (sleep quality and sleep efficiency), with good model fit (CFI = 0.960, AGFI = 0.924, TLI = 0.925, RMSEA = 0.085). Test-retest reliability was satisfactory for intervals of one week or more (r = 0.721 ~ 0.753). Using a one-week timeframe, the total score and two dimensions exhibited good reliability (r = 0.769 ~ 0.881), but only the total score and sleep quality showed high correlations with ISI and ASSQ (r = 0.701 ~ 0.839). Throughout the tracking, monthly responses correlated well with the most recent weeks (r = 0.732 ~ 0.866). Conclusion: The PSQI demonstrates a two-factor structure in Chinese athletes, with sleep quality being predominant. Test-retest reliability within a one-month timeframe is unstable, suggesting a one-week timeframe performs better. Distinguishing between the two dimensions, employing shorter timeframes, and incorporating objective measures are recommended.

Chronotype characteristics of professional athletes in China: a comprehensive descriptive study.

BACKGROUND: Chronotype has gained recognition as a significant factor in enhancing athletic performance. This study aimed to deepen our understanding of athletes' sleep chronotypes and provide a foundation for developing evidence-based training and competition programs. By comprehensively describing and analyzing the chronotype characteristics of Chinese professional athletes, considering individual and sports factors, sleep quality and habits, and mental energy, this research aimed to contribute valuable insights to the field. METHODS: A sample of 1069 professional athletes from sports teams in Shanghai completed the Athlete Sleep Screening Questionnaire and the Athlete Mental Energy Scale to assess chronotype, sleep quality, sleep-influencing habits, and mental energy. RESULTS: Among athletes, sleep typology fell within the intermediate range, slightly leaning toward morningness. Male athletes and those who engaged in static sports displayed a greater propensity for morningness. Age correlated with a preference for eveningness. High-level athletes exhibited a stronger inclination toward eveningness. Sleep quality issues were associated with an inclination toward eveningness. Daily caffeine intake and the habit of using electronic devices before bedtime are also linked to eveningness. Chronotype demonstrated the ability to predict various dimensions of athletes' mental energy. It was the strongest predictor of vigor, but the loadings were smaller than those of sleep quality. CONCLUSION: Chinese athletes' chronotypes primarily exhibit distinct characteristics related to individual factors such as gender, sports discipline, and ranking, as well as habits like caffeine consumption and electronic device use. Moreover, these sleep patterns demonstrate predictive capabilities across all dimensions of athletes' mental energy. This study sheds light on Chinese athletes' unique sleep chronotype attributes, enriching our understanding of sleep patterns among professional athletes under various systems. These insights offer an initial basis for enhancing the effectiveness of athlete scheduling and training management.

Reliability and validity of the Chinese version of the Athens insomnia scale for non-clinical application in Chinese athletes.

Purpose: This study aimed to revise and examine the reliability and validity of the Chinese version of the Athens Insomnia Scale for Non-clinical Application (AIS-NCA) among Chinese athletes. Additionally, the study tested the scale in non-athlete individuals with similar sleep management practices to further analyze its cultural specificity among Chinese athletes and make preliminary inferences about its applicability in other Chinese populations. Methods: Four hundred twenty-six Chinese professional athletes and 779 high school students participated in this research. Both athletes and students were divided into two parallel groups for exploratory and confirmatory factor analyses. Additionally, three athlete samples and one student sample were established for reliability and validity assessments. Among athletes, the Pittsburgh Sleep Quality Index, the Epworth Sleepiness Scale, the Athlete Sleep Screening Questionnaire, and the Warwick-Edinburgh Mental Well-Being Scale were employed to evaluate convergent and discriminant validity. Re-test reliability was evaluated at intervals of 1 and 2 weeks. In the case of students, convergent and discriminant validity were tested using the Pittsburgh Sleep Quality Index and the General Self-Efficacy Scale, with re-test reliability assessed at two-week intervals. Results: The Chinese version of the AIS-NCA consists of six items, categorized into two dimensions: sleep problems and daytime functioning. This structure explained 65.08% (athletes) and 66.22% (students) of the variance. Confirmatory factor analysis revealed good model fit, with values of χ2/df = 2.217, CFI = 0.975, AGFI = 0.929, TLI = 0.953, and RMSEA = 0.076 among athletes, and χ2/df = 3.037, CFI = 0.979, AGFI = 0.947, TLI = 0.961, and RMSEA = 0.072 among students. The scale demonstrated a reasonable degree of measurement invariance. The overall scale and two subscales exhibited strong reliability and validity among athletes. Similar results in terms of reliability and validity were also observed within the student sample. Conclusion: The Chinese version of the AIS-NCA shows promise as an assessment tool for evaluating the sleep quality of Chinese athletes. It effectively captures both sleep-related concerns and daytime functionality within the athlete population. The scale demonstrates solid reliability and validity in professional athletes and holds potential for application across various other demographic groups in China.

The effect of short-term cranial electrotherapy stimulation on sleep quality in athletes: A pilot study.

BACKGROUND: To verify the effect of a 5-day cranial electrotherapy stimulation (CES) intervention on sleep quality in professional athletes. METHODS: 25 professional athletes with poor sleep quality participated in the study. Athletes belonging to the CES group (12 athletes) received a 5-day CES intervention, and those in the control group did not receive any intervention. Objectively and subjected assessed sleep quality was measured 1 week before and after the intervention using an Actigraphy activity recorder, Pittsburgh sleep quality index (PSQI), and Insomnia Severity Index (ISI). RESULTS: Objectively measured sleep efficiency increased after CES intervention (P = .013), while the difference between the pretest and posttest of the control group was not significant. For total sleep time (TST), the main effects and interaction were not significant. However, the analysis on wake after sleep onset showed wake after sleep onset decreased after CES intervention (P = .015). No significant interaction was found in subjectively assessed sleep quality but only revealed an improvement in both groups. CONCLUSION: The CES intervention of 30 minutes per day for 5 consecutive days enhanced objective sleep quality in athletes with sleep quality problems. The intervention increased sleep efficiency by lowering awake time after falling asleep.

A comparative study of Chinese women 3 × 3 basketball players exercise load in Tokyo Olympic preparation cycle.

Objective: The aim of this study was to compare the variances in-game loads exhibited by Chinese women's 3 × 3 basketball team across different stages of the preparation cycle for the Tokyo Olympic Games, and to summarize the fundamental regulations governing Chinese women's 3 × 3 basketball training and games, in order to establish a theoretical research foundation for the team's new preparation cycle. Methods: This study measured load-related data during the preparation and main competition periods of the 2019-2021 Tokyo Olympics, from April to August 2019 and from April to June 2021. The aim was to compare the changes and differences in a load of competition during different stages and to explore patterns of load changes during the preparation period. This study used wearable devices authorized by FIFA and NBA, along with the Catapult GPS performance monitoring system from Australia (Catapult&Polar Team) as instruments for collecting sports load data. The OptimEye S5 device was worn around the athlete's neck to collect data prior to the game, while the Open Field™ system was utilized for data editing and report generation post-game. Results: Compared to the primary competition load during the 2019 preparation period, the 2021 preparation period exhibited significant increases and decreases (p < 0.05) in competition load, high-intensity load, the number of explosive moves, the number of high-intensity acceleration, several changes to the left and right, and the number of explosive jumps. During the 2021 preparation period, the mean heart rate, mean heart rate percentage, and mean speed of the race demonstrated significant decreases in comparison to the race during the 2019 preparation period (p < 0.05). Throughout the training period spanning from 2019 to 2021, no significant differences were observed in running distance and maximum speed (p > 0.05). Conclusion: The findings of this study reveal that the national training team has fostered positive adaptive changes in athletes, resulting in a significant enhancement in both load and sports performance science data during competition from 2019 to 2021.

Psychological changes in athletes infected with Omicron after return to training: fatigue, sleep, and mood.

Background: This study aims to analyze the changes of approximately 1 month in fatigue, sleep, and mood in athletes after returning to training following infection with the COVID-19 Omicron strain and provide recommendations for returning to training after infection. Methods: Two hundred and thirty professional athletes who had returned to training after being infected with COVID-19 in December 2022 were recruited to participate in three tests conducted from early January 2023. The second test was completed approximately 1 week after the first, and the third was completed about 2 weeks after the second. Each test consisted of completing scales and the exercise-induced fatigue measure. The scales included a visual analog scale, the Athens Insomnia Scale for non-clinical application, and the Depression-Anxiety-Stress scale. The exercise task was a six-minute stair climb test, and athletes evaluated subjective fatigue levels before and after exercise using another Visual Analog Scale and the Karolinska Sleepiness Scale. Results: After returning to training, athletes' physical fatigue decreased initially but increased as training progressed. Cognitive fatigue did not change significantly. The exercise task led to elevated levels of physical fatigue after a longer duration of training. Sleep quality problems decreased rapidly after the start of training but remained stable with prolonged training. Depression levels continued to decline, while anxiety levels only reduced after a longer duration of training. Stress levels decreased rapidly after the start of training but did not change with prolonged training. Conclusion: Athletes who return to training after recovering from COVID-19 experience positive effects on their fatigue, sleep, and mood. It is important to prioritize anxiety assessment and interventions during the short period after returning and to continue monitoring fatigue levels and implementing recovery interventions over a longer period of time.

The effect of prolonged closed-loop management on athletes' sleep and mood during COVID-19 pandemic: Evidence from the 2022 Shanghai Omicron Wave.

Closed-loop management of athletes at the training base is a compromise approach that balanced epidemic prevention and sports training during the COVID-19 pandemic. This study investigated the impact of prolonged closed-loop management on athletes' sleep and mood during the 2022 Shanghai Omicron wave. The Pittsburgh Sleep Quality Index and the Profile of Mood States were used to assess the sleep and mood states of 110 professional athletes in "closed-loop management" at the training base after 1 and 2 months of closed-loop management, respectively, to characterize changes in sleep and mood with prolonged closed-loop management. After two months of control, the sleep and mood of 69 athletes and students of the same age were measured using the Pittsburgh Sleep Quality Index and Perceptual Stress Scale, as well as the Warwick-Edinburgh Mental Well-being Scale, to compare the differences in sleep and mood between athletes undergoing closed-loop management and the general population who were managed in the community. Paired sample t-tests and independent sample t-tests were used for comparisons across different time intervals and different management approaches. Results showed that with the time of closed-loop management increased, athletes woke up earlier (p = 0.002), slept less (p = 0.024), and became angrier (p = 0.014); athletes had poorer overall sleep quality (p < 0.001) but lower stress level (p = 0.004) than those who were outside the base. In closed-loop management, the athletes were able to maintain a stable sleep and mood state. Sports team administrators must be aware of the need to improve athletes' sleep quality and help athletes to agree with this approach of management.

Differential impact of heat and hypoxia on dynamic oxygen uptake and deoxyhemoglobin parameters during incremental exhaustive exercise.

Purpose: This study aims to explore the relationship between the dynamic changes in oxygen uptake (V˙O2) and deoxyhemoglobin (HHb) and peripheral fatigue in athletes during incremental exhaustive exercise under different environmental conditions, including high temperature and humidity environment, hypoxic environment, and normal conditions. Methods: 12 male modern pentathlon athletes were recruited and performed incremental exhaustive exercise in three different environments: normal condition (23°C, 45%RH, FiO2 = 21.0%, CON), high temperature and humidity environment (35°C, 70%RH, FiO2 = 21.0%, HOT), and hypoxic environment (23°C, 45%RH, FiO2 = 15.6%, HYP). Gas metabolism data of the athletes were collected, and muscle oxygen saturation (SmO2) and total hemoglobin content in the vastus lateralis muscles (VL) were measured to calculate the deoxyhemoglobin content. Linear and nonlinear function models were used to fit the characteristic parameters of V˙O2 and HHb changes. Results: The results showed that compared to the CON, V˙O2, V˙CO2, and exercise time were decreased in the HOT and HYP (p < 0.05). ΔEV˙O2 and OUES were reduced in the HOT and HYP compared to the CON (p < 0.05). The Gas exchange threshold in the CON corresponded to higher V˙O2 than in the HYP and HOT (p < 0.05). ΔEV˙O2-1 was reduced in the HOT compared to the HYP (p < 0.05). ΔEHHb was higher in the HOT compared to the CON (p < 0.05). ΔEHHb-1 was increased in the HYP compared to the CON (p < 0.05). There was a negative correlation between ΔEHHb and corresponding V˙O2⁡max in the HOT (r = -0.655, p < 0.05), and a negative correlation between ΔEHHb-1 and corresponding V˙O2⁡max in the HYP (r = -0.606, p < 0.05). Conclusion: Incremental exhaustive exercise in hypoxic environment and high temperature and humidity environments inhibits gas exchange and oxygen supply to skeletal muscle tissue in athletes. For athletes, the accelerated deoxygenation response of skeletal muscles during incremental exhaustive exercise in high temperature and humidity environments, as well as the excessive deoxygenation response before BP of deoxyhemoglobin in hypoxic environment, may be contributing factors to peripheral fatigue under different environmental conditions.