The relationship between objective measures of sleep and training load across different phases of the season in American collegiate football players

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.

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 Association Between Alterations in Redox Homeostasis, Cortisol, and Commonly Used Objective and Subjective Markers of Fatigue in American Collegiate Football

PURPOSE

To assess associations between a free oxygen radical test (FORT), free oxygen radical defense test (FORD), oxidative stress index, urinary cortisol, countermovement jump (CMJ), and subjective wellness in American college football.

METHODS

Twenty-three male student athlete American college football players were assessed over 10 weeks: off-season conditioning (3 wk), preseason camp (4 wk), and in season (3 wk). Assessments included a once-weekly FORT and FORD blood sample, urinary cortisol sample, CMJ assessment including flight time, reactive strength index modified and concentric impulse, and a daily subjective wellness questionnaire. Linear mixed models analyzed the effect of a 2 within-subject SD change in the predictor variable on the dependent variable. The effects were interpreted using magnitude-based inference and are presented as standardized effect size (ES) ± 90% confidence intervals.

RESULTS

Small negative associations were observed between FORT-flight time, FORT-fatigue, FORT-soreness (ES range = -0.30 to -0.48), FORD-sleep (ES = 0.42 ± 0.29), and oxidative stress index soreness (ES = 0.56 ± 0.29). Small positive associations were observed between FORT-cortisol (ES = 0.36 ± 0.35), FORD-flight time, FORD reactive strength index modified and FORD-soreness (0.37-0.41), oxidative stress index concentric impulse (ES = 0.37 ± 0.28), and with soreness-concentric impulse, soreness-flight time, and soreness reactive strength index modified (0.33-0.59). Moderate positive associations were observed between cortisol-concentric impulse and cortisol-sleep (0.57-0.60).

CONCLUSION

FORT/FORD was associated with CMJ variables and subjective wellness. Greater amounts of subjective soreness were associated with decreased CMJ performance, increased FORT and cortisol, and decreased FORD.

Effects of sleep disturbance on functional and physiological outcomes in collegiate athletes: A scoping review

OBJECTIVE

To investigate sleep disturbances and circadian timing changes on functional and physiological correlates specifically in collegiate athletes.

DESIGN

Scoping Review.

DATA SOURCES

PubMed MEDLINE, SPORT-Discus, CINAHL, ERIC ProQuest, Web of Science.

ELIGIBILITY CRITERIA

Articles in English, studying college athletes 18-24 years old, employing a sleep measurement, and a comparison measure of cognitive, academic performance, athletic performance, injury rate, biomarkers and physiological measures, or imaging.

RESULTS

Thirty articles met inclusion criteria. There was wide range of study design, sport studied, modality used to measure sleep, frequency of sleep measurements, and functional and physiological outcomes across studies. Sleep measurements varied greatly in frequency of data collection and type of measurement tool, with the majority using a sleep questionnaire. While all variables of interest were represented within the review, most had a focus on cognitive performance, athletic performance, or injury rate as a function of sleep. Studies using biomarkers and physiological measures or imaging were largely underrepresented. Few studies used biomarkers and physiological measures, and one study used imaging measures. Most studies in this review reported negative cognitive and academic outcomes with worse sleep quality and quantity.

CONCLUSIONS

Sleep is critical to maintaining optimal health and collegiate athletes represent a unique population given their unique time constraints, stresses, and sleep behaviors. Findings on athletic performance and injury rate as a function of sleep were mixed. Employing standardized objective methodologies in future work will allow for better understanding of the influence of sleep on the overall well-being and performance of college athletes.