Sleep quality and athletic performance according to chronotype

Improvement of Jet Lag and Travel Fatigue Symptoms and Their Association with Prior International Travel Experience in Junior Athletes

Jet lag and travel fatigue can occur after crossing multiple time zones in a short period of time, possibly affecting various aspects of an athlete's behavior. However, there are few studies regarding this issue, particularly considering junior athletes. This study aimed to investigate and quantify the symptoms of jet lag and travel fatigue and the factors impacting these conditions. A survey was completed by 41 Japanese junior athletes (21 men and 20 women), competing at an international game in Finland, to assess their performance, sleeping habits, digestion, fatigue, and jet lag on the first day of arrival and on the opening day of the competition. Although athletes awoke less often during sleep on the opening day of the competition compared with the first day, sleep time, ease of falling asleep, and sleep quality decreased significantly. Prior experience traveling abroad for international competitions was positively associated with improvements regarding ease of falling asleep (coefficient = 2.22, p = 0.01), quality of sleep (coefficient = 2.16, p = 0.02), and alertness after waking up (coefficient = 1.85, p = 0.05) by the opening day of the competition when compared with the results for athletes who had no such prior experiences. Junior athletes experience symptoms of jet lag and travel fatigue that may persist until the day of competition, and prior experience traveling abroad may help in alleviating their symptoms.

Relationship between sleep quality and gravitational Tolerance

BACKGROUND

The purpose of this study was to investigate the relationship between sleep quality and gravitational tolerance because sleep could directly affect physiological variables of the human body.

METHODS

For the present study, 157 male Korea Air Force Academy cadets were recruited. They were assigned into a gravity (G)-tolerance test pass group (GP, n = 87) and a G-tolerance test fail group (GF, n = 70). All participants were assessed for G-tolerance test and Pittsburgh Sleep Quality Index (PSQI), a self-report questionnaire. Physical fitness test was performed based on the physical fitness test of the Ministry of National Defense of Korea.

RESULTS

Independent t-test showed that PSQI global score (p < 0.001), PSQI sleep quality (p < 0.001), PSQI sleep onset latency (p = 0.009), PSQI sleep disturbance (p < 0.001), and PSQI daytime dysfunction (p < 0.001) were significantly different between the two groups. Participants with PSQI score less than 5 were more likely to have a longer G-tolerance test time (OR = 4.705, 95% CI = 2.00-11.05). Additionally, associations between those with PSQI score less than 5 (OR = 4.567, 95% CI = 1.94-10.74) were after adjusting (< 30 s and ≥ 30 s) for covariates. A negative correlation was found between G-tolerance test time and PSQI global score (p < 0.001). Negative correlations were found among 3 km running, push-up (p < 0.001), and sit-up (p < 0.001). A positive correlation was found between push-up and sit-up (p < 0.001).

CONCLUSION

In conclusion, participants with good sleep quality were 4.705 times more likely to have longer G-tolerance test time. Thus, it is important for aircraft pilots to manage their sleep quality. Pre-pilots should also improve their sleep quality to pass the G-tolerance test.

Circadian rhythm in sportspersons and athletic performance: A mini review

Circadian rhythms in the physiological and behavioral processes of humans play a crucial role in the quality of living and also in the magnitude of success and failure in various endeavors including competitive sports. The rhythmic activities of the body and performance in sportspersons do have a massive impact on their every cutthroat competition. It is essential to schedule sports activities and training of players according to their circadian typology and time of peak performance for improved performance and achievement. In this review, the focus is on circadian rhythms and diurnal variations in peak athletic performance in sportspersons. Accuracy and temporal variability in peak performance in an individual could be attributed to various factors, namely chronotype, time of the day, body temperature, jetlag, hormones, and prior light exposure. Circadian rhythm of mood, alertness, T-core, and ultimately athletic performance is not only affected by sleep but also by circadian variations in hormones, such as cortisol, testosterone, and melatonin. There are, however, a few reports that are not consistent with the conclusions drawn in this review. Nevertheless, circadian rhythm and performance among sportspersons and athletes are important areas of research. This review might be useful to the managers and policymakers associated with competitive sports and athletic events.

Waking Up to the Issue! Research Inattention and Sex-Related Differences Warrant More Sleep Studies in Female Athletes

Understanding sleep patterns and behaviors of athletes is essential for developing targeted sleep-based interventions for implementation in practice. However, more than double the number of sleep studies have examined male athletes compared with female athletes, making the current understanding of sleep patterns, behaviors, and interventions among athletes disproportionately indicative of men. Consequently, this review demonstrates the need for more female-specific sleep data among athlete populations due to research inattention and sex-related differences. Specifically, this review identifies variations in sleep patterns and behaviors between male and female athletes, as well as physiological and lifestyle factors that potentially affect sleep patterns and behaviors across the lifespan, specifically in female athletes. In this regard, evidence suggests some female athletes experience longer sleep durations and better objective sleep quality, but similar or worse subjective sleep quality compared with male athletes. Additionally, scheduling training in the morning or throughout the day may benefit sleep in some female athletes. Considering sleep disorders, women may be at greater risk for insomnia and restless legs syndrome compared with men, which may be attributed to pregnancy, as well as a higher prevalence of anxiety and depressive symptoms, iron deficiency without anemia, and use of psychotropic medication among women. Finally, the menstrual cycle, menstrual disorders, oral contraceptive use, and the postpartum period have been shown to exert detrimental effects on sleep patterns and behaviors and should theoretically be considered when monitoring and managing sleep in female athletes.

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.

Circadian preference and physical and cognitive performance in adolescence: A scoping review

Adolescence is a crucial period of development which coincides with changes in circadian rhythmicity. This may augment the impact of circadian preference on performance in this group. We aimed to scope the literature available on chronotypes and their effect on physical and mental aspects of performance in adolescents. Studies were identified by systematically searching bibliographical databases and grey literature. The Morningness-Eveningness Questionnaire was the most frequently reported tool for circadian preference assessment. Academic achievement was the most prevailing outcome, with evidence suggesting that morning type adolescents tend to outperform evening types, yet the results vary depending on multiple factors. Performance in tests of intelligence and executive functions was generally better at optimal times of the day (synchrony effect). Physical performance was examined in 8 studies, with very heterogeneous outcomes. Although the associations between circadian preference and performance in adolescents are evident in some areas, there are many factors that may be involved in the relationship and require further investigation. This review highlights the assessment of physical performance in relation to chronotypes, the multidimensional assessment of circadian preference, and the need for longitudinal studies as priorities for further research.Protocol: OSF Registration - Public registration, DOI: 10.17605/OSF.IO/UCA3Z.

The effect of Pilates exercises on sleep quality and fatigue among female students dormitory residents

BACKGROUND

This study aims to investigate the effect of Pilates exercises on sleep and fatigue among female college students residing in the dormitory.

METHODS

This quasi-experimental study, two parallel groups was performed on 80 single female college students (40 per group), between 18 to 26 years old who lived in the two dormitories. One dormitory was considered as the intervention group and another as the control group. The Pilates group received three one-hour Pilates exercise sessions per week for eight weeks and the control group maintained their routine activities. The Pittsburgh Sleep Quality Index (PSQI) and the Multidimensional Fatigue Inventory (MFI-20) were used respectively to assess sleep quality and fatigue levels, at three time points: baseline, end of week four, and eight follow-ups. Fisher's exact, Chi-square, independent sample t-test and repeated measurements were used.

RESULTS

Overall, 66 participants completed the study (32 and 35 participants in the Pilates and control groups, respectively). After four and eight weeks of intervention, the overall mean score of sleep quality improved significantly (p < 0.001). At week four of the intervention, the Pilates group had a significantly lower mean score for subjective sleep quality and daytime dysfunction than the control group (p < 0.001 and p < 0.002, respectively), although sleep duration and habitual sleep efficiency improved after eight weeks of intervention (p < 0.04 and p < 0.034, respectively). Additionally, the overall mean score of fatigue and its dimensions in weeks four and eight of the intervention in the Pilates group were significantly lower compared to the control group (p < 0.001).

CONCLUSION

After eight weeks of Pilates exercises implementation, most components of sleep quality significantly improved; however, the effect of Pilates exercises on fatigue was evident from week four onward. Trial registration This trial was registered on 2/6/2015 in the Iranian Registry of Clinical Trials with the IRCT ID: IRCT201412282324N15. URL of registry: https://www.irct.ir/trial/1970 .

Type 2 Diabetes: Also a “Clock Matter”?

Background: We investigated whether chronotype is associated with glycemic control, antidiabetic treatment, and risk of developing complications in patients with type 2 diabetes (T2DM). Methods: The diabetologists filled out an online questionnaire on the Google Form platform to collect the following parameters of subjects with T2DM: body mass index (BMI), fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c), diabetes history, antidiabetic treatment, diabetic complications, and chronotype categories. Results: We enrolled 106 subjects with T2DM (M/F: 58/48; age: 63.3 ± 10.4 years; BMI: 28.8 ± 4.9 kg/m2). Thirty-five point eight% of the subjects showed a morning chronotype (MC), 47.2% an intermediate chronotype (IC), and 17% an evening chronotype (EC). EC subjects reported significantly higher HbA1c (p < 0.001) and FPG (p = 0.004) values, and higher prevalence of cardiovascular complications (CVC) (p = 0.028) and of subjects taking basal (p < 0.001) and rapid insulin (p = 0.01) compared to MC subjects. EC subjects reported significantly higher HbA1c (p < 0.001) and FPG (p = 0.015) than IC subjects. An inverse association was found between chronotype score, HbA1c (r = −0.459; p < 0.001), and FPG (r = −0.269; p = 0.05), remaining significant also after adjustment for BMI, age, and disease duration. Conclusions: EC is associated with higher prevalence of CVC and poorer glycemic control independently of BMI and disease duration in subjects with T2DM.

Time-of-Day Effect on Postural Balance and Its Associations with Menopausal Symptoms in Postmenopausal Women

Postmenopausal women suffer from postural balance issues. During a 24-hour time span, postural performance undergoes radical changes as influenced by the circadian rhythm. In this study, we aimed to investigate time-of-day effects on postural balance in postmenopausal women and balance relationships with menopausal symptoms. Two groups of women, aged 40-50 years, participated in this study: a menopausal group and a control group. We evaluated their postural balance and menopausal symptoms (mood, sleepiness and fatigue) in five sessions over the course of a day: at 06:00 hours, at 10:00, at 14:00, at 18:00 and at 22:00. The results showed that postural balance (center of pressure area (CoP_area)) values of postmenopausal women were significantly worse (p < .05) at 22:00. Moreover, at this time-of-day, participants in the menopausal group were more tired, less vigilant and experienced a lower mood. We found negative correlations between postural balance and both mood and fatigue levels. However, there was no time-of-day effect on postural balance, mood, fatigue, and sleepiness among participants in the control group. Thus, time-of-day should be considered a factor to control when assessing postural balance and designing intervention studies for postmenopausal women; and it is important for these women to be cautious of fall risks at night, as they are then less stable than at other times-of-day.

The effects of sleep disturbance and chronotype on baseline vestibular/ ocular motor screening in collegiate athletes

BACKGROUND

The vestibular/ocular motor screening (VOMS) is a clinically validated screening tool for concussion management. Multiple factors have been known to influence VOMS performance such as preexisting migraine and mood disorders. Poor sleep is an another important variable that warrants investigation as a modifier on the VOMS that may need to be considered during administration.

AIM

This study aims to examine whether self-reported sleep difficulties significantly modify baseline VOMS symptom provocation in collegiate athletes.

METHODS

A total of 191 collegiate student-athletes completed a pre-season baseline VOMS and the 16-item Athlete Sleep Screening Questionnaire (ASSQ) before the start of their respective sport season. The ASSQ was used to establish sleep health variables consisting of hours of sleep per night, sleep difficulties when traveling for sport, chronotype (e.g., morning or evening person), and a sleep disturbance score (SDS) category of none, mild, and moderate + severe.

RESULTS

Those who reported sleep disturbances when traveling for sport on that respective ASSQ item had higher pre-test VOMS symptoms (P < 0.001) and symptom provocation on convergence (P = 0.015), horizontal vestibular ocular reflex (VOR) (P = 0.008), and vertical VOR (P = 0.039). There were worse pre-test symptoms (P = 0.015) and provocation on horizontal VOR (P = 0.046) in the moderate + severe SDS group than no SDS. The moderate + severe SDS group reported worse symptom provocation on the horizontal (P = 0.018) and vertical VOR (P = 0.010), and VMS (P = 0.017). No differences were found on VOMS symptom provocation for hours of sleep or chronotype.

CONCLUSIONS

These results show agreement with previous symptom and neurocognitive data in that sleep difficulties among collegiate athletes may have an important role in the interpretation of baseline concussion testing. It may be beneficial to utilize sleep assessments with baseline concussion testing when using the VOMS as the clinical concussion measurement modality.

RELEVANCE FOR PATIENTS

The addition of sleep assessment may aid sports medicine practitioners in properly interpreting baseline VOMS scores. Pre-season baseline testing may need to be delayed if athletes report with poor sleep in the acute period prior.

Chronotype and Social Jetlag Influence Performance and Injury during Reserve Officers' Training Corps Physical Training

Sleep and circadian rhythms are critically important for optimal physical performance and maintaining health during training. Chronotype and altered sleep may modulate the response to exercise training, especially when performed at specific times/days, which may contribute to musculoskeletal injury. The purpose of this study was to determine if cadet characteristics (chronotype, sleep duration, and social jetlag) were associated with injury incidence and inflammation during physical training. Reserve Officers' Training Corps (ROTC) cadets (n = 42) completed the Morningness/Eveningness Questionnaire to determine chronotype, and 1-week sleep logs to determine sleep duration and social jetlag. Salivary IL-6 was measured before and after the first and fourth exercise sessions during training. Prospective injury incidence was monitored over 14 weeks of training, and Army Physical Fitness Test scores were recorded at the conclusion. Chronotype, sleep duration, and social jetlag were assessed as independent factors impacting IL-6, injury incidence, and APFT scores using ANOVAs, chi-squared tests, and the t-test where appropriate, with significance accepted at p < 0.05. Evening chronotypes performed worse on the APFT (evening = 103.8 ± 59.8 vs. intermediate = 221.9 ± 40.3 vs. morning = 216.6 ± 43.6; p < 0.05), with no difference in injury incidence. Sleep duration did not significantly impact APFT score or injury incidence. Social jetlag was significantly higher in injured vs. uninjured cadets (2:40 ± 1:03 vs. 1:32 ± 55, p < 0.05). Exercise increased salivary IL-6, with no significant effects of chronotype, sleep duration, or social jetlag. Evening chronotypes and cadets with social jetlag display hampered performance during morning APFT. Social jetlag may be a behavioral biomarker for musculoskeletal injury risk, which requires further investigation.

God save the owls! Religiosity moderates the relationship between morningness-eveningness and depressive symptoms

Studies show that eveningness preference and depressive symptoms are positively related. However, little is known about possible factors that could reduce this association. In the present study, we examine the moderating effects of religiosity on the relationship between eveningness and depressive symptoms. The main analyses were conducted on a group of 606 individuals (300 women and 306 men) aged 18 to 36 years (M = 29.00, SD = 4.95). The participants completed the Composite Scale of Morningness, the Patient Health Questionnaire-9, and the Centrality of Religiosity Scale. Our results confirmed earlier findings that eveningness was positively related to depressive symptoms. The magnitude of this association decreased with higher religiosity. This lead to the conclusion that religiosity may act as a protective factor against elevated depressive symptoms among evening-oriented individuals.

Relationship between sleep quality, mood state, and performance of elite air-rifle shooters

Background

To evaluate the impact of pre-competition sleep quality on the mood and performance of elite air-rifle shooters.

Methods

Elite shooters who participated in an air-rifle shooting-competition from April 2019 to October 2019 were evaluated using actigraphy, including Total Sleep Time (TST), Sleep Efficiency (SE), Sleep Latency (SL), Wake-time after Sleep Onset (WASO). Sleep quality was assessed by Pittsburgh sleep quality index (PSQI) and Profile of Mood State (POMS). Mood state was assessed by Competitive State Anxiety Inventory-2.

Results

Study included 23 shooters, of them 13 male and 10 female with the mean age 23.11 ± 4.82 years. The average time to fall asleep was 20.6 ± 14.9 min, TST was 7.0 ± 0.8 h and SE was 85.9 ± 5.3%. Average sleep quality was 5.2 ± 2.2 and tended to decrease as the competition progressed. Pre-competition sleep time in female athletes was significantly higher compared to the competition day (P = 0.05). Pre-competition SL was significantly longer in women than in men (P = 0.021). During training and pre-competition, the tension, fatigue, depression, and emotional disturbance were significantly lower in athletes with good sleep quality. Athletes with good sleep quality had significantly more energy. The PSQI total score positively correlated with cognitive anxiety (r = 0.471, P < 0.01), and somatic anxiety (r = 0.585, P < 0.01), and negatively correlated with energy (− 0.504, P < 0.01) and self-confidence scores (r = − 0.523, P < 0.01).

Conclusion

Poor sleep quality negatively impacted the mood of athletes; however, sleep indices and competition performance of athletes during competitions were not significantly correlated.

Biological Rhythm and Chronotype: New Perspectives in Health

The circadian rhythm plays a fundamental role in regulating biological functions, including sleep–wake preference, body temperature, hormonal secretion, food intake, and cognitive and physical performance. Alterations in circadian rhythm can lead to chronic disease and impaired sleep. The circadian rhythmicity in human beings is represented by a complex phenotype. Indeed, over a 24-h period, a person’s preferred time to be more active or to sleep can be expressed in the concept of morningness–eveningness. Three chronotypes are distinguished: Morning, Neither, and Evening-types. Interindividual differences in chronotypes need to be considered to reduce the negative effects of circadian disruptions on health. In the present review, we examine the bi-directional influences of the rest–activity circadian rhythm and sleep–wake cycle in chronic pathologies and disorders. We analyze the concept and the main characteristics of the three chronotypes.