Article
To read the full-text of this research, you can request a copy directly from the authors.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Sleep is a behavioral state that is characterized by relative immobility and reduced responsiveness and can be distinguished from coma or anesthesia by its rapid reversibility [1]. Sleep has a number of functions, which include metabolism modulation and the repair of organic tissue [2] There is an increasing body of evidence indicating that sleep debt negatively impacts skeletal muscle trophism [3] and that acute sleep deprivation can lead to muscle atrophy [4], mainly of type II fibers in rats [5,6] in addition to impairing the recovery of injured muscles [7]. Similarly, epidemiological studies have shown that markers of poor sleep are associated with age-related muscular decline and that sleep can play a crucial role in the etiological mechanisms of skeletal muscle disease [8,9]. ...
... Regarding hormonal and inflammatory markers, the participants showed, on average, adequate testosterone, GH, and cortisol levels; reduced levels of IGF-1; and increased levels of IL-6 and IL-10, two anti-inflammatory cytokines. 3 ) 192.20 ± 30.84 228.00 ± 62.07 Leukocytes (thousands/mm 3 ) 5.14 ± 0.92 6.46 ± 1.78 Neutrophils (thousands/mm 3 ) 3.14 ± 0.60 3.84 ± 1.43 Eosinophils (thousands/mm 3 ) 0.08 ± 0.07 0.25 ± 0.042 Basophils (thousands/mm 3 ) 0.03 ± 0.02 0.03 ± 0.01 Typical lymphocytes (thousands/mm 3 ...
... Regarding hormonal and inflammatory markers, the participants showed, on average, adequate testosterone, GH, and cortisol levels; reduced levels of IGF-1; and increased levels of IL-6 and IL-10, two anti-inflammatory cytokines. 3 ) 192.20 ± 30.84 228.00 ± 62.07 Leukocytes (thousands/mm 3 ) 5.14 ± 0.92 6.46 ± 1.78 Neutrophils (thousands/mm 3 ) 3.14 ± 0.60 3.84 ± 1.43 Eosinophils (thousands/mm 3 ) 0.08 ± 0.07 0.25 ± 0.042 Basophils (thousands/mm 3 ) 0.03 ± 0.02 0.03 ± 0.01 Typical lymphocytes (thousands/mm 3 ...
Article
Full-text available
Unlabelled: Sleep and exercise have an important role in the development of several inflammation-related diseases, including sarcopenia. Objective: To investigate the effects of 12 weeks of resistance exercise training on sleep and inflammatory status in sarcopenic patients. Methods: A randomized controlled trial comparing resistance exercise training (RET) with a control (CTL) was conducted. Outcomes were obtained by physical tests, polysomnography, questionnaires, isokinetic/isometric dynamometry tests, and biochemical analysis. Results: Time to sleep onset (sleep latency) was reduced in the RET group compared to the CTL group (16.09 ± 15.21 vs. 29.98 ± 16.09 min; p = 0.04) after the intervention. The percentage of slow-wave sleep (N3 sleep) was increased in the RET group (0.70%, CI: 7.27-16.16 vs. -4.90%, CI: 7.06-16.70; p = 0.04) in an intention to treat analysis. Apnea/hour was reduced in the RET group (16.82 ± 14.11 vs. 7.37 ± 7.55; p = 0.001) and subjective sleep quality was improved compared to the CTL (-1.50; CI: 2.76-6.14 vs. 0.00; CI: 1.67-3.84 p = 0.02) in an intention-to-treat analysis. Levels of interleukin-10 (IL-10) (2.13 ± 0.80 vs. 2.51 ± 0.99; p < 0.03) and interleukin-1 receptor antagonist (IL-1ra) (0.99 ± 0.10 vs. 0.99 ± 0.10 ng/mL; p < 0.04; delta variation) were increased in the RET group. Conclusions: RET improves sleep parameters linked to muscle performance, possibly due to an increase in anti-inflammatory markers in older sarcopenic patients.
... However, it seems that the lack of sleep may activate autonomic and stress systems which further stimulates the production of pro-inflammatory cytokines (Faraut et al., 2012). As such reduced sleep may compromise muscle recovery through creating a more catabolic state when sleep restriction or deprivation occur (Dattilo et al., 2011). It has been shown that glycogen level is affected by the lack of sleep in a lab-based experiments, due to the increased sleep drive by augmented wakefulness leading to increased use of glycogen overnight (Petit et al., 2014). ...
... Indeed, it has been shown that the lack of sleep may affect the level of muscle damage (Dattilo et al., 2011), the repletion of glycogen stores (Skein et al., 2011) as well as cognitive functions (Skein et al., 2013). While these assumptions regarding the effects of the lack of sleep seem logical, the real impact of sleep on recovery kinetics after a match has never been investigated in an ecological setting. ...
... However these mechanisms might be inhibited by a lack of sleep . Indeed, it appears that lack of sleep compromises muscle recovery through creating greater catabolic states as well as negating energy store restoration (Dattilo et al., 2011;Skein et al., 2013). Therefore, due to the potential negative effect of sleep restriction after a match or training, it appears important to promote sleep in order to improve recovery kinetics. ...
Thesis
Full-text available
This PhD investigated the importance of sleep in the recovery processes of rugby union players. Study 1 found students and student-athletes presented low sleep quality assessed with the Pittsburgh Sleep Quality (65% ≤5 indicating poor sleep quality). Moreover, student-athletes presented a higher intra-individual variability (small to moderate). In study 2, different age groups of rugby union players presented low total sleep time (≤7 hours) and efficiency (≤85%). However, only small differences in sleep schedule were observed between age groups. Study 2 investigated the validity of self-reported sleep parameters and found a large mean bias (87 min) when compared with actigraphy for sleep duration. Additionally, unclear relationships with subjective sleep quality were found. Study 3 investigated the validity, reliability and sensitivity of a standardised run (i.e. Running Load Index). The results demonstrated a large relationship with leg stiffness (r=0.62) and with a coefficient of variation of 11.5%. Moreover, a large increase in Running Load Index was found after a week of training highlighting its sensitivity. Study 4 highlighted a later fall asleep and wake up time, shorter total sleep time and lower subjective sleep quality post-match. Moreover, collisions, travel time and kick-off time explained most of the changes in sleep compared with match load. Despite, a decrease in perceived wellness (small to very large) and neuromuscular function (small) were observed, sleep had marginal effect on their respective changes. The effect of acute sleep extension on recovery was investigated in Study 5. The results suggested that such as strategy has beneficial effects on cognitive function (i.e. Stroop task). Altogether the results from this PhD suggest that acute changes in sleep post-match affect mainly perceptual and cognitive measures rather than neuromuscular function. Nevertheless, more work is necessary to consider the effect of chronic lack of sleep on post-match recovery.
... Good sleep quality predicts good mental and physical health 2 and it is recognized as one of the most effective recovery strategies 3 . In recent years, the general population has experienced a reduction in sleep duration which can generate potential risks to the individual's health 4 . In this sense, the interest about the athletes' sleep has increased, considering its beneficial effects to musculoskeletal recovery 3 . ...
... Some factors may explain the worsening in sleep quality in athletes such as increased cortisol concentrations 5 , increased sympathetic activity 6 , increased central body temperature 7 , presence of muscle pain 8 , as well as anxiety and thoughts about sports competition 9 . Thus, typical changes in hormone secretion patterns induced by sleep debt can decrease protein synthesis and increase protein degradation, impairing skeletal muscle integrity 4,10 ; therefore, sleep deprivation can affect the process of sports recovery in this population 11 . ...
Article
Full-text available
Objectives: Sleep is essential for musculoskeletal and cognitive recovery. Adolescent athletes tend to sleep poorly compared to adults and it may predispose them to sports injuries. Our aims are to estimate whether the quantity/quality of sleep are associated with sports injuries in adolescent athletes and to compare the quantity/quality of sleep between the training and competition seasons, and the school vacation period. Material and Methods: It was a cohort study with 19 track and field athletes of both sexes, aged between 12 and 21 years. We evaluated their sleep-wake habit through actigraphy during three phases: 1 - mid-season, 2 - competition, and 3 - school vacation. The previous six months injury history and the occurrence of injuries in a six-month follow-up were recorded. Logistic regression and variance analysis were performed. The significance level used was 0.05. Results: Wake after sleep onset (WASO) predicted previous injuries (OR=1.144) and time awake (TA) predicted injury occurrence (OR=0.974). TA decreased from phase 2 to phase 3 (p=0.004), total sleep time (TST) increased from phase 2 to phase 3 (p=0.012), and WASO decreased between phases 1 and 2 (p=0.001) and between phases 1 and 3 (p=0.025). Conclusion: Our study demonstrated that the quantity and quality of sleep were associated with musculoskeletal injuries in adolescent track and field athletes. Previous injuries were predicted by WASO and the occurrence of injuries was predicted by TA. Furthermore, during the vacation period they had lower TA and WASO, and higher TST than on school days.
... Hormone secretion control, immune response, oxidative stress, and biorhythms, however, have been considered related-factors between sleep health and phenotypes of body composition. First, results in this study might be caused by the effects of several hormones (Insulin-like Growth Factor 1 (IGF-1), testosterone, etc.) controlled by the quality and duration of sleep [17,18]. The amount of secreted IGF-1 was rapidly reduced in the sleep-deprived group of rats [17]. ...
Article
Full-text available
Background An association between sleep behaviors and muscle-fat mass is continuously interesting topic. Methods Based on the survey on sleep behaviors (quality and duration), the poor quality of sleep was evaluated when the subject did not feel satisfied after sleep, while the good quality was evaluated as they feel refreshed. A total of 19,770 participants were divided into the four groups according to changes in sleep quality: Good-to-Good (those who continuously maintained good quality), Good-to-Poor (those who reported initial good quality but subsequently reported a poor quality), Poor-to-Poor (those who continuously maintained poor quality), and Poor-to-Good (those who reported improved quality of sleep). As changes in skeletal muscle and fat mass index [kg/m²] were estimated by a validated prediction equation, multiple linear regression was used to calculate adjusted mean (adMean) of muscle and fat mass according to changes in sleep behavior. Results When sleep duration decreased and quality of sleep deteriorated (from good to poor), fat mass index significantly increased (adMean: 0.087 for the Good-to-Good group and 0.210 for the Good-to-Poor group; p-value = 0.006). On the other hand, as the quality of sleep deteriorated, skeletal muscle mass more decreased despite the maintained sleep duration (adMean: -0.024 for the Good-to-Good group and − 0.049 for the Good-to-Poor group; p-value = 0.009). Conclusion Our results showed that changes in sleep quality and duration affect changes in muscle and fat mass. Thus, we suggest maintaining a good quality of sleep, even if sleep duration is reduced, to preserve muscle mass and inhibit the accumulation of fat.
... Acute and chronic sleep loss are widely recognized to negatively influence physiological outcomes 16 . For instance, impaired sleep reduces the expression of anabolic hormones (e.g., GH, IGF-1 and testosterone), in addition to increasing the production of molecules with catabolic potential (e.g., myostatin and glucocorticoid hormones), promoting a scenario that can impair muscle protein synthesis (MPS) 17,18 . In fact, a recent study demonstrated that a single night of sleep deprivation is sufficient to promote an 18% reduction in MPS, indicating mechanistic precursors driving the metabolic dysfunction and body composition changes such as reduced lean body mass 15 . ...
Article
Systemic lupus erythematosus (SLE) patients report worse health-related quality of life (HRQL), fatigue, anxiety, depression, and sleep quality, when compared to the general population and other chronic diseases. Furthermore, cardiometabolic diseases are highly prevalent in SLE and are also associated with these parameters. Thus, it is plausible to suggest that SLE patients with a high cardiovascular risk may report worse results for these parameters. The aim of the study is to describe HRQL, fatigue, anxiety and depression symptoms, and sleep quality in a sample of SLE patients with a high cardiovascular risk profile (i.e., BMI between 25 and 40 kg/m ² and/or dyslipidemia, hypertension, or diabetes). This was a cross-sectional study where patients were assessed for (i) demographic, anthropometric, and disease-related parameters, (ii) HRQL, (iii) fatigue, (iv) anxiety and depression symptoms, and (v) sleep quality. One-hundred patients completed the study; however, only 87 patients were assessed for sleep quality data. Patients averaged 41.7 ± 9 years, and most patients were classified as overweight/obese (87%). SF-36 scores for physical and mental components summary were 51.3 ± 9.6 and 54.2 ± 15.6, respectively, with “bodily pain” and “role emotional” presenting the lower scores. The total SLEQOL score was 105.1 ± 42.0, with lower scores reported for “self-image” and “mood.” Fatigue score was 30.8 ± 8.9, and 78% and 93% reported severe symptoms of anxiety and depression, respectively. The average sleep effectiveness was 82.9 ± 6.6%. Sleep latency, total time in bed (TTiB), and total sleep time (TST) were 8.4 ± 8.9, 495.8 ± 79.7, and 409.7 ± 69.9 min, respectively. Patients reported an average of 17.8 ± 6.2 WE, with 4.5 ± 1.5 min duration and a WASO of 77.7 ± 36.6 min. Despite similar HRQL, fatigue, and sleep quality parameters to those reported by other SLE populations, SLE patients with a high cardiovascular risk had a higher prevalence of depression and anxiety. Understanding SLE patients’ quality of life and psychological symptoms is of utmost importance to improve disease management. The findings of this study highlight the need for more intensive and global care regarding mental health when considering a high cardiovascular risk in SLE.
... Em essa perspectiva, as evidências científicas atuais nos dizem que existem múltiplos fatores relacionados ao maior rendimento esportivo como a predisposição genética (Figueira et al., 2012), a suplementação nutricional (Close, Hamilton, Philp, Burke & Morton, 2016;Lanhers et al., 2017), a execução técnica (Green & Comfort, 2007;Wagner, Evans, Weir, Housh & Johnson, 1992), os métodos de recuperação com o objetivo de manter e melhorar o desempenho competitivo (Dupuy, Douzi, Theurot, Bosquet & Dugué, 2018), a qualidade do sono (Dattilo et al., 2011;Durán Agüero et al., 2015). Embora esses fatores tenham sido relacionados ao maior rendimento esportivo, nem sempre isso ocorre, pois a preparação esportiva é um conjunto de sistemas que, de forma integrada, facilitam a preparação do atleta e que podem ser influenciados por múltiplos fatores (ambientais, biológico, cultural) (Reverdito, Scaglia & Montagner, 2013). ...
Article
Full-text available
RESUMO O objetivo desta pesquisa é apontar os estudos que descrevem variáveis que se associam a um impacto positivo no desempenho competitivo em atletas de para powerlifting. Para desenvolver o estudo foi utilizada as diretrizes Preferred Reporting Items for Systematic Reviews e Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) e os estudos foram extraídos de bases de dados eletrônicas como Web of Science, PubMed, Scopus, ScienceDirect e EBSCO. Foi realizado um processo de seleção por título, resumo e texto completo, de acordo com os critérios de inclusão e exclusão. Inicialmente foram identificados 154 estudos que após a eliminação de duplicatas e aplicação dos critérios de inclusão, foram selecionados 8 artigos originais para análise qualitativa. Os resultados indicam que existem fatores fisiológicos e biomecânicos relacionados ao desempenho esportivo. A ingestão de placebo, uso de monohidrato de creatina, percentual de massa magra, predisposição genética e diversos métodos de recuperação de curto e médio prazo, como agulhamento seco e imersão em água fria, são fatores fisiológicos relacionados ao desempenho. Em relação aos fatores biomecânicos, foi evidenciado que a mensuração da preensão da barra se relaciona com maior produção de força e velocidade propulsora média.
... La calidad del sueño es muy importante, este garantiza un adecuado descanso que facilita los procesos de recuperación fisiológica y psicológica para afrontar las actividades de la vida cotidiana y futuros entrenamientos de manera óptima por parte de los atletas. Un sueño inadecuado genera varias alteraciones disminuyendo la capacidad de recuperación, e.g., incremento de la producción de adrenalina, noradrenalina, dopamina, cortisol, entre otras, que disminuyen la síntesis de proteína muscular e incrementan su degradación, acrecentando un ambiente celular proteolítico que se asocia con estados de sarcopenia y caquexia, además, de múltiples alteraciones a nivel cognitivo potencialmente perjudiciales para la salud (Dattilo et al., 2011). A pesar de que la escala de somnolencia Epworth ha sido ampliamente utilizada junto a otros instrumentos, la escala indica si se ha tenido el suficiente descanso nocturno a través de la ausencia o presencia de estados de somnolencia diurna. ...
Article
Full-text available
Sports trainers have a wide variety of instruments and methods to control training to identify the level of internal or external load experienced by the athlete to avoid an injury. The objective of this study was to explore the training load middle-distance athletes prior to a sports injury that resulted in the temporary suspension of training. The semi-structured interview technique was used in the retrospective phase to inquire about the means and methods used for load control. In the prospective phase, the recording of the mean heart rate (HRm), Session Rating of Exertion Perception (sRPE), Monotony Index (MI), Fatigue Index (FI), Hydration levels by urine color and Epworth Sleepiness Scale were used. The results indicate that the sports injury occurred prior to several high intensity sessions expressed in sRPE and in the week of higher volume, with this situation not being reflected through the FCm, nor in the week of higher value in IM and IF. Additionally, with levels of dehydration and an increase in the somnolence scale being evidenced in the last weeks of training. It is concluded that some methods to control training load do not reflect the real load experienced by the athlete, therefore, it is important to implement various mechanisms to reduce the risk of injury.
... Acute and chronic sleep loss are widely recognized to negatively influence physiological outcomes 16 . For instance, impaired sleep reduces the expression of anabolic hormones (e.g., GH, IGF-1 and testosterone), in addition to increasing the production of molecules with catabolic potential (e.g., myostatin and glucocorticoid hormones), promoting a scenario that can impair muscle protein synthesis (MPS) 17,18 . In fact, a recent study demonstrated that a single night of sleep deprivation is sufficient to promote an 18% reduction in MPS, indicating mechanistic precursors driving the metabolic dysfunction and body composition changes such as reduced lean body mass 15 . ...
Article
Full-text available
We aimed to investigate associations between sleep quality with selected quantitative and qualitative parameters of health in older individuals with obesity. Cross-sectional assessment (n = 95 men/women; ≥ 65 years; BMI ≥ 30 kg/m²) of sleep quality, body composition, handgrip strength, quality-of-life, anxiety/depression. Mean PSQI score was 6.3. Poor sleepers (n = 49) presented lower appendicular lean mass (ALM) (16.2 vs 17.8 kg; p = 0.0273), ALM/BMI (0.47 vs 0.53 kg/BMI; p = 0.0085), fat mass (48.6 vs 46.6%; p = 0.0464), handgrip strength (19.7 vs 22.0 kgf; p = 0.0542) and handgrip/BMI (0.57 vs 0.66 kgf/BMI; p = 0.0242) than good sleepers. They also had higher anxiety (8.6 vs 5.6; p = 0.0100) and depression (4.8 vs 3.2; p = 0.0197) scores, worse health-related quality-of-life and lower scores in mental (62.8 vs 73.0; p = 0.0223) and physical (52.9 vs 67.3; p = 0.0015) domains. Adjusted models showed that PSQI was negatively associated with ALM (β = − 0.13, 95% CI − 0.25; − 0.01) and health-related quality of life on physical (β = − 2.76, 95% CI − 3.82; − 1.70) and mental (β = − 2.25, 95% CI − 3.38; − 1.12) domains, and positively associated with anxiety (β = 0.57; 95% CI 0.26; 0.87) and depression (β = 0.31; 95% CI 0.13; 0.49). Poor sleep quality associates with impaired selected quantitative and qualitative parameters of health. Additionally, sleep quality was shown as an independent predictor of ALM, health-related quality-of-life, anxiety and depression in older individuals with obesity.
... As evocated by Dattilo et al. (2011), insufficient sleep duration and poor sleep quality generate a decrease in the activity of protein synthesis pathways and an increase in the activity of degradation pathways, promoting the loss of muscle mass, which subsequently weakens muscle strength (Kim et al. 2016). In our case, anthropometric influence in particular segment length (Hraski et al. 2015), may ensure the proper development of muscle strength performance during growth which may explain the lack of relationship between sleep parameters and strength in our players. ...
... The correct expression of circadian rhythmicity is fundamental for the body homeostasis and humans perform optimally when all biological rhythms, including sleep-wake cycle, are in sync [1,2]. Sleep is a basic requirement for human health and serves important psychological and physiological functions [3]. As recommended by the National Sleep Foundation [4], adults should obtain at least seven to nine h of sleep per night to maintain optimal health and functioning and it has been shown that the absence of adequate sleep is linked to a large number of adverse outcomes, including impairments to cognitive performance [5], mood [6], and appetite regulation [7], as well as critical metabolic [8] and immunologic processes [9]. ...
Article
Full-text available
Purpose The aim of this observational cohort study was to assess actigraphy-based sleep characteristics and pain scores in patients undergoing knee or hip joint replacement and hospitalized for ten days after surgery. Methods N =20 subjects (mean age: 64.0±10.39 years old) wore the Actiwatch 2 actigraph (Philips Respironics, USA) to record sleep parameters for 11 consecutive days. Subjective scores of pain, by a visual analog scale (VAS), were constantly monitored and the following evaluation time points were considered for the analysis: pre-surgery (PRE), the first (POST1), the fourth (POST4), and the tenth day (POST10) after surgery. Results Sleep quantity and timing parameters did not differ from PRE to POST10, during the hospitalization whereas sleep efficiency and immobility time significantly decreased at POST1 compared to PRE by 10.8% ( p =0.003; ES: 0.9, moderate) and 9.4% ( p =0.005; ES: 0.86, moderate) respectively, and sleep latency increased by 18.7 min (+320%) at POST1 compared to PRE ( p =0.046; ES: 0.70, moderate). Overall, all sleep quality parameters showed a trend of constant improvement from POST1 to POST10. VAS scores were higher in the first day post-surgery (4.58 ± 2.46; p =0.0011 and ES: 1.40, large) compared to POST10 (1.68 ± 1.58). During the time, mean VAS showed significant negative correlations with mean sleep efficiency ( r = −0.71; p =0.021). Conclusion Sleep quantity and timing parameters were stable during the entire hospitalization whereas sleep quality parameters significantly worsened the first night after surgery compared to the pre-surgery night. High scores of pain were associated with lower overall sleep quality.
... Finally, the results of the associations between the components of physical fitness and minutes of sleep are different by gender, although in both there was an association in upper-body muscle strength; in girls, an association was found with cardiorespiratory fitness, and in boys, an association was found with lower-body muscle strength and speed. This may be due to the fact that good physical fitness values are factors that could benefit sleep, a situation that could be explained because a greater amount of sleep is associated with an increase in IGF-1, which is an anabolic hormone that plays an important role in the maintenance of muscle mass [87], and that on the contrary, a lack of sleep decreases the activity of the protein synthesis pathways and increases the activity of the degradation pathways, favoring the loss of muscle mass and thus hindering muscle recovery [88]. It is important to note that not many studies have studied the strength-sleep relationship in children, so further epidemiological research and intervention studies are needed to determine whether these relationships manifest. ...
Article
Full-text available
Background: In recent decades, the school population has undergone behavioral changes that have affected their health and adult life. The current educational scenario presents high levels of sedentary behavior, physical inactivity, low physical fitness, high levels of obesity, and non-compliance with sleep recommendations. In Chile, the scientific evidence on associations between these behaviors is incipient. Objective: To analyze the association between sedentary behavior, physical activity, and physical fitness with BMI and minutes of sleep in Chilean children aged 10 to 11 years. Methods: A non-probabilistic convenience sample of 222 schoolchildren aged 10 to 11 years. The variables measured were body composition (BMI), cardiorespiratory fitness (20 m shuttle run test), lower and upper muscular strength (long jump test and handgrip dynamometry), speed (4 × 10 m running), and flexibility (sit and reach test). Physical activity and sleep were measured by accelerometers. Results: Of the participants, 60.4% and 90.6% did not comply with sleep and physical activity recommendations, respectively. Physical fitness was higher in boys in all components. The results of the linear regression show that in girls, moderate-vigorous-intensity physical activity, lower- and upper-body muscular strength, and cardiorespiratory endurance were associated with BMI and sleep. In boys, light-intensity physical activity and upper-body muscular strength were associated with both variables. Conclusions: Physical activity intensity, strength, and cardiorespiratory fitness were associated with BMI and sleep; however, physical activity intensity and associated physical fitness components differed by gender.
... Long naps (90 minutes) and/or not separated at least 30 minutes from the start of training are associated with sleep inertia (decreased cognitive capacity after awakening) and lack of arousal, decreasing performance. Likewise, naps should be taken before 4 p.m. so as not to interfere with nocturnal sleep (Vitale et al., 2019;Bird et al., 2013;Dattilo et al., 2011;Romdhani et al., 2021;Lastella et al., 2021). ...
Article
Full-text available
Masters athletes have been considered a paradigm of successful aging, which research has shown that many of the age-associated physiological changes are more related to external factors to aging itself, such as sedentary lifestyle and deconditioning. Sprint training always poses a challenge, even more in such demanding athletes as masters sprinters, given that age mainly affects those physical capabilities that are most determinant of sprint performance, such as speed, strength, flexibility, and coordination. The main purpose of this paper was to comprehensively review masters sprinters training, emphasizing certain aspects that are especially relevant in these athletes, such as training principles, specific resistance training, recovery strategies, and invisible training.
... Long naps (90 minutes) and/or not separated at least 30 minutes from the start of training are associated with sleep inertia (decreased cognitive capacity after awakening) and lack of arousal, decreasing performance. Likewise, naps should be taken before 4 p.m. so as not to interfere with nocturnal sleep (Vitale et al., 2019;Bird et al., 2013;Dattilo et al., 2011;Romdhani et al., 2021;Lastella et al., 2021). ...
Article
Full-text available
Masters athletes have been considered a paradigm of successful aging, which research has shown that many of the age-associated physiological changes are more related to external factors to aging itself, such as sedentary lifestyle and deconditioning. Sprint training always poses a challenge, even more in such demanding athletes as masters sprinters, given that age mainly affects those physical capabilities that are most determinant of sprint performance, such as speed, strength, flexibility, and coordination. The main purpose of this paper was to comprehensively review masters sprinters training, emphasizing certain aspects that are especially relevant in these athletes, such as training principles, specific resistance training, recovery strategies, and invisible training.
... Sleep is an essential process in humans (Nicholson 2006). It plays a significant role in the maintenance of metabolism, body weight, blood glucose levels, blood pressure, cognitive processes, cardiovascular health and many hormonal axes (Dattilo et al. 2011). A strong association between sleep quality and psychological well-being is also reported in many studies. ...
Article
Full-text available
Well-being is considered a positive state influenced by one’s mental, physical, emotional and cultural factors. High-level well-being enables a person to live at full potential. In this study, we investigated the level of well-being and its associated factors among nursing students studying at a selected university in Ras Al Khaimah in the United Arab Emirates. A quantitative descriptive study was conducted among undergraduate nursing students enrolled in this university. A convenient sampling technique was used to recruit the participants. Measures included the WHO-5 well-being index, a lifestyle behaviour questionnaire, the Pittsburgh sleep quality index and a brief resilience scale. Nearly two-thirds (65.4%) of the study participants reported good well-being, whereas the remaining 34.6% reported low well-being. In general, better well-being was found to be associated with moderate or vigorous physical activity for at least 30 minutes three or more times a week (p < 0.05), and a habit of skipping breakfast (p < 0.05). It was also found to be associated with better subjective sleep quality (p < 0.001), less sleep latency (p < 0.01), fewer sleep disturbances (p < 0.001), and less daytime dysfunction (p < 0.001). These results support the need to improve the well-being of nursing students. We recommend interventions that promote physical activity and sleep quality to improve the well-being of undergraduate nursing students.
... These alterations may cause muscular atrophy and muscle fiber loss. 58 Strong evidence exists that the circadian clock is essential for the physiology and operation of muscles. 59 A sign of declining physiologic function, prolonged sleep duration is comparable to impaired neuromuscular function. ...
Article
Full-text available
Testicular torsion is a serious urologic emergency that can present with unusual or atypical history and examination. Classical pain from testicular torsion is of sudden onset, significantly severe, and is accompanied by nausea and vomiting. However, in some patients, the initial scrotal pain appears to considerably subside within the next few hours. In others, testicular torsion tends to occur while sleeping, and many patients recount a history of being woken up from sleep by intense pain. Furthermore, some patients in this subset can resume normal activities and even sleep through the night with little or no discomfort, without a perceived need for pain medications. Other patients initially experience mild pain, which worsens over time. Consequently, these patients are less likely to be evaluated immediately. In view of these atypical cases, the question remains unanswered regarding sleep as a predisposing factor for testicular torsion. This narrative review focuses on exploring the association between sleep and testicular torsion.
... Sleep parameters have been considered the best posttraining recovery measure for athletes (32) because there is effective muscle regeneration during sleep (11). Assessing sleep parameters is particularly important because athletes tend to have insufficient sleep time and worse quality than the general population (32). ...
Article
Ferreira, ABdM, Ribeiro, BLL, Batista, EdS, Dantas, MP, and Mortatti, AL. The influence of different training load magnitudes on sleep pattern, perceived recovery, and stress tolerance in young soccer players. J Strength Cond Res 37(2): 351–357, 2023—The aim of this study was to analyze the influence of 3 weeks on sleep parameters, perceived recovery, and stress tolerance in young soccer players using different training load magnitudes. A total of 13 young male soccer athletes (15.9 ± 0.5 years; 68.7 ± 6.1 kg; 170 ± 7 cm) who performed 3 typical training weeks with different workloads were analyzed. The external training load (ETL) was verified by the PlayerLoad method, and the internal training load (ITL) was determined using the session rating of perceived exertion method. Sleep was monitored using a wrist-actigraphy monitor. Sleep variables, including total time in bed (TTB), total sleep time (TST), sleep latency (SL), wake after sleep onset (WASO), and sleep efficiency (SE), were evaluated across all nights of sleep. The recovery status was assessed with the perceived recovery status (PRS) scale, and the stress tolerance was monitored using the “daily analysis of life demands of athletes” questionnaire. There was an increase in sleep time during the week with the highest training load (week 2) (TTB: +35 minutes, TST: +46 minutes, SL: −5 minutes, SE: +3%). There was no difference in the PRS or in the stress tolerance during the evaluation weeks. A very large within-individual correlation was observed between ITL and ETL (r = 0.78) and moderate within-individual correlation between ETL and TST (r = 0.34), between ITL and TST (r = 0.45), and between ITL and SE (r = 0.359). These results showed that there was an increase in TST during a microcycle with intensified loads, without impairing bedtime and resulting in maintenance of the perceived recovery or stress tolerance values.
... It is known that sleep deprivation promotes neurocognitive deficits, dysregulation of physiological functions regulated by the circadian rhythm (eg, temperature, blood pressure), and incomplete muscle recovery, which may accumulate over time in chronic partial sleep loss (restriction or deprivation). [51][52][53] Daytime napping and physical performance A similar pattern of benefits of napping was observed in our results for different parameters of physical performance, such as strength, endurance and speed, both after normal sleep and partial sleep deprivation. Although considerable heterogeneity was detected between the studies included in the normal sleep and partial sleep deprivation analyses, the SMD was high in both cases. ...
Article
Objective: To estimate the association between daytime napping and cognitive and physical sport performance and fatigue after normal sleep and partial sleep deprivation (less sleep duration than necessary). Design: Systematic review and meta-analysis. Data sources: The PubMed, Scopus, Web of Science, Cochrane Central, SportDiscus and PsycINFO databases. Eligibility criteria for selecting studies: Randomised controlled trials on the effect of daytime napping on sport performance and fatigue available from inception to 2 December 2022. Standardised mean differences (SMD) and their 95% compatibility intervals (CI) were estimated with the DerSimonian-Laird method through random effect models. Results: In the 22 included trials, 291 male participants (164 trained athletes and 127 physically active adults) aged between 18 and 35 years were studied. When performed after a normal night of sleep, napping from 12:30 hours to 16:50 hours (with 14:00 hours being the most frequent time) improved cognitive (SMD=0.69, 95%CI: 0.37 to 1.00; I2 =71.5%) and physical performance (SMD=0.99, 95%CI: 0.67 to 1.31; I2 =89.1%) and reduced the perception of fatigue (SMD=−0.76, 95%CI: −1.24 to –0.28; I2 =89.5%). The positive effects of napping were also confirmed after partial sleep deprivation. Overall, the benefits were higher with a nap duration between 30 and <60min and when the time from nap awakening to test was greater than 1 hour. Conclusions: After a night of normal sleep or partial sleep deprivation, a daytime nap between 30 and <60min has a moderate-to-high effect on the improvement of cognitive performance and physical performance and on the reduction of perceived fatigue. PROSPERO registration number CRD42020212272.
... Despite the importance of sleep for physiologic function [1][2][3][4], falling asleep is not easy for modern people, and sleep disturbance is prevalent in the general population [5][6][7]. The importance of sleep has been particularly emphasized for older patients with chronic medical conditions because they frequently experience sleep disturbance which significantly influences their disease outcome and life expectancy [4,[8][9][10][11][12]. ...
Article
Full-text available
Sleep disturbance is prevalent in patients with degenerative spinal disease, and recent studies have reported that surgical treatment is more effective for improving sleep quality than conservative treatment. We aimed to investigate the perioperative changes of sleep problems in patients who underwent surgical treatment for degenerative spinal disease with a concurrent sleep disorder, and presented them according to various clinical profiles possibly associated with sleep disturbance. In addition, we identified factors associated with poor sleep improvement after surgery. This study used data from the Korea Health Insurance Review and Assessment Service database from 2016 to 2018. We included 3183 patients aged ≥19 years who underwent surgery for degenerative spinal disease and had a concurrent sleep disorder. Perioperative changes in the two target outcomes, including the use of sleep medication and hospital visits owing to sleep disorders, were precisely investigated according to factors known to be associated with sleep disturbance, including demographics, comorbidities, and spinal regions. Logistic regression analysis was performed to identify factors associated with poor improvement in terms of sleep medication after surgery. All estimates were validated using bootstrap sampling. During the 1-year preoperative period, the use of sleep medications and hospital visits owing to sleep disorder increased continuously. However, they abruptly decreased shortly after surgical treatment, and throughout the 1-year postoperative period, they remained lower than those in the late preoperative period. At the 1-year follow-up, 75.6% (2407 of 3183) of our cohort showed improvement in sleep medication after surgery. Multivariable analysis identified only two variables as significant factors associated with non-improvement in sleep medication after surgery: depressive disorder (odds ratio (OR) = 1.25 [1.06–1.48]; p = 0.008), and migraine (OR = 1.42 [1.04–1.94]; p = 0.028). We could not investigate the actual sleep quality and resultant quality of life; however, our results justify the necessity for further high-quality studies that include such information and would arouse clinicians’ attention to the importance of sleep disturbance in patients with degenerative spinal disease.
... In the review of Chennaoui et al. (2015) the different physiological and psychological pathways through which sleep and physical activity impact each other have been well described. Acute sleep loss has been observed to result in immuneinflammatory changes such as increased pro-inflammatory cytokine, growth hormone and testosterone concentrations after physical exercise (Abedelmalek et al., 2013) and to down regulate activity of the protein synthesis pathway that repairs muscle damage and trigger contractile function deficits during recovery (Dattilo et al., 2011). While in terms of chronic sleep restriction, Haack et al. (2007) reported that reducing sleep duration to 4 h/night across 10 days increased levels of plasma interleukin-6 and increased pain ratings. ...
Article
Full-text available
Sleep is one of the most important aspects of recovery, and is known to be severely affected by hypoxia. The present position paper focuses on sleep as a strong moderator of the altitude training-response. Indeed, the response to altitude training is highly variable, it is not a fixed and classifiable trait, rather it is a state that is determined by multiple factors (e.g., iron status, altitude dose, pre-intervention hemoglobin mass, training load, and recovery). We present an overview of evidence showing that sleep, and more specifically the prolonged negative impact of altitude on the nocturnal breathing pattern, affecting mainly deep sleep and thus the core of physiological recovery during sleep, could play an important role in intra- and interindividual variability in the altitude training-associated responses in professional and recreational athletes. We conclude our paper with a set of suggested recommendations to customize the application of altitude training to the specific needs and vulnerabilities of each athlete (i.e., primum non nocere). Several factors have been identified (e.g., sex, polymorphisms in the TASK2/KCNK5, NOTCH4 and CAT genes and pre-term birth) to predict individual vulnerabilities to hypoxia-related sleep-disordered breathing. Currently, polysomnography should be the first choice to evaluate an individual’s predisposition to a decrease in deep sleep related to hypoxia. Further interventions, both pharmacological and non-pharmacological, might alleviate the effects of nocturnal hypoxia in those athletes that show most vulnerable.
... It is important to note, however, that both groups reported fewer disruptions as recovery progressed, but anxiety and persistent anxiety blunted this benefit over time. Anxiety can negatively impact sleep, and poor sleep is associated with deleterious molecular processes in muscle cells that diminish the body's ability to recover after muscle damage caused by exercise or injury [51]. ...
Article
Full-text available
This prospective cohort study examined the impact of high anxiety levels on psychological state and gait performance during recovery in runners with lower body injuries. Recreational runners diagnosed with lower body injuries who had reduced running volume (N = 41) were stratified into groups using State Trait Anxiety Inventory (STAI) scores: high anxiety (H-Anx; STAI ≥40 points) and low anxiety (L-Anx; STAI <40 points). Runners were followed through rehabilitation to return-to-run using monthly surveys. Main outcome measures included kinesiophobia (Tampa Scale of Kinesiophobia, TSK-11), Positive and Negative Affect Schedule (PANAS; Positive and negative scores), Lower Extremity Function Scale (LEFS), running recovery (University of Wisconsin Running Injury and Recovery Index [UWRI]) and CDC Healthy Days modules for general health, days of anxiety/tension, disrupted sleep and work/usual activities. Running biomechanics were assessed at baseline and the final visit using 3D motion capture and a force-plated treadmill. The time to return-to-running for was 5.0±3.1 and 7.9±4.1 months for L-Anx and H-Anx, respectively and participants who withdrew (n = 15) did so at 7.7±6.2 months. L-Anx maintained low anxiety and H-Anx reduced anxiety from baseline to final visit (STAI = 31.5 to 28.4 points, 50.4 to 37.8 points, respectively), whereas the withdrawn runners remained clinically anxious at their final survey (41.5 to 40.3 points; p < .05). Group by time interactions were found for PANAS positive, LEFS UWRI, general health scores, and days feeling worry, tension and anxiety (all p < .05). Final running performance in L-Anx compared to H-Anx was most improved with cadence (8.6% vs 3.5%; p = .044), impact loading rate [-1.9% vs +8.9%] and lower body stiffness [+14.1% vs +3.2%; all p < .05). High anxiety may identify runners who will experience a longer recovery process, health-related functional disruptions, and less optimization of gait biomechanics during rehabilitation after a lower extremity injury.
... Sleep deprivation leads to increased injuries, reduced muscle glycogen stores and, consequently, alters muscle recovery. These changes affect different aspects of performance 3,9,10 . Therefore, the athlete needs adequate preparation so that on the day of the competition the consequences are as small as possible. ...
Article
Full-text available
Sleeping and eating before and during an ultramarathon can directly affect an athlete's performance, who may also have their physiological adaptations and recovery process hindered by sleeping problems. Endurance and ultra-endurance athletes may have different sleep and nutrition profiles. Thus, this study aimed to describe the sleep profile (during preparation) and nutritional profile (during competition) of endurance (10-20km) and ultra-endurance (50-100km) running athletes. For this, 16 healthy volunteers answered questionnaires related to sleep quality (Pittsburgh sleep quality index), chronotype (morningness-eveningness questionnaire), and sleepiness (excessive daytime sleepiness questionnaire). Immediately after a competition, a form prepared by the research team about nutritional variables and volunteers' food records during the competition was applied. According to test scoring criteria (Pittsburgh sleep quality index >5; sleepiness >10), endurance running athletes showed low sleep quality. In addition, all athletes showed consumption of carbohydrates and lipids below the recommended, but excessive consumption of proteins. A positive association between sleepiness and sodium intake in endurance runners was observed (r=0.862; p=0.027). Sleep efficiency and race time showed a negative correlation only for ultra-endurance athletes (r=-0.834; p=0.039). The data obtained show that endurance athletes presented more sleep pattern alterations, however, endurance and ultra-endurance athletes showed inadequate nutritional consumption during the competition.
... Adequate sleep facilitates complex higher cognitive processes such as memory consolidation and learning [26], whereas bouts of insufficient sleep act as a catalyst for decreased cognitive performance, manifested by increased reaction times, lapses in attention, and cognitive dysfunction [10]. An association between patterns of reduced sleep and decreased performance and function is also observed in other physiological processes [12,15,30,32]. However, the complex nature of sleep coupled with difficulties in controlling behavioural and environmental factors has made it challenging to determine the precise mechanisms that underpin declines in performance and physiological function. ...
Article
Full-text available
There currently exists a modern epidemic of sleep loss, triggered by the changing demands of our 21st century lifestyle that embrace ‘round-the-clock’ remote working hours, access to energy-dense food, prolonged periods of inactivity, and on-line social activities. Disturbances to sleep patterns impart widespread and adverse effects on numerous cells, tissues, and organs. Insufficient sleep causes circadian misalignment in humans, including perturbed peripheral clocks, leading to disrupted skeletal muscle and liver metabolism, and whole-body energy homeostasis. Fragmented or insufficient sleep also perturbs the hormonal milieu, shifting it towards a catabolic state, resulting in reduced rates of skeletal muscle protein synthesis. The interaction between disrupted sleep and skeletal muscle metabolic health is complex, with the mechanisms underpinning sleep-related disturbances on this tissue often multifaceted. Strategies to promote sufficient sleep duration combined with the appropriate timing of meals and physical activity to maintain circadian rhythmicity are important to mitigate the adverse effects of inadequate sleep on whole-body and skeletal muscle metabolic health. This review summarises the complex relationship between sleep, circadian biology, and skeletal muscle, and discusses the effectiveness of several strategies to mitigate the negative effects of disturbed sleep or circadian rhythms on skeletal muscle health.
... Sleep plays an essential role in both cognitive and physiologic function [1,2]. Therefore, sleep disturbance can not only have detrimental effects on quality of life, but also potentially cause mental and physical illness, eventually increasing the risk of mortality [3,4]. ...
Article
Full-text available
Spinal surgeons have not yet considered sleep disturbance an area of concern; thus, a comprehensive study investigating the epidemiology of sleep disturbance in patients with degenerative spinal disease is yet to be conducted. This study aimed to fill this research gap by investigating the epidemiology of sleep disturbance in patients who underwent spinal surgery for degenerative spinal disease and identifying the associated risk factors. This nationwide, population-based, cohort study, used data from January 2016 and December 2018 from the Korea Health Insurance Review and Assessment Service database. This study included 106,837 patients older than 19 years who underwent surgery for degenerative spinal disease. Sleep disorder was initially defined as a diagnosis of a sleep disorder made within one year before the index surgery and identified using the International Classification of Diseases, 10th revision, codes F51 and G47 (main analysis). We also investigated the use of sleep medication within 90 days prior to the index surgery, which was the target outcome of the sensitivity analysis. The prevalence of sleep disturbance was precisely investigated according to various factors, including demographics, comorbidities, and spinal region. Logistic regression analysis was performed to identify the independent factors associated with sleep disturbance. The results of the statistical analysis were validated using sensitivity analysis and bootstrap sampling. The prevalence of sleep disorder was 5.5% (n = 5847) in our cohort. During the 90 days before spinal surgery, sleep medication was used for over four weeks in 5.5% (n = 5864) and over eight weeks in 3.8% (n = 4009) of the cohort. Although the prevalence of sleep disturbance differed according to the spinal region, the spinal region was not a significant risk factor for sleep disorder in multivariable analysis. We also identified four groups of independent risk factors: (1) Age, (2) other demographic factors and general comorbidities, (3) neuropsychiatric disorders, and (4) osteoarthritis of the extremities. Our results, including the prevalence rates of sleep disturbance in the entire patient population and the identified risk factors, provide clinicians with a reasonable reference for evaluating sleep disturbance in patients with degenerative spinal disease and future research.
... This hormonal profile represents dysregulation of the HPA and hypothalamic-pituitarygonadal axes, and is consistent with a catabolic state where protein synthesis is reduced and protein degradation is increased. During critical illness, sleep disruption may therefore contribute to loss of muscle mass and impaired muscle recovery [138]. Even short periods of acute sleep loss (e.g. 1 night) are sufficient to induce anabolic resistance and promote a pro-catabolic state [139]. ...
Chapter
Sleep is a biologic necessity that sustains life and maintains health and wellbeing. When sleep is disrupted, meaning an abnormality in duration, timing, continuity, or quality, it threatens to negatively affect a myriad of biologic functions and deteriorates health. Critically ill adults in the intensive care unit (ICU) are at high risk for sleep disruption, and consequently are at high risk for resultant negative biologic effects from this disrupted sleep. Given the complex nature of critical illness, few high-quality studies have examined biologic changes in response to sleep disruption in the ICU. As such, this chapter primarily focuses on short-term, relevant biologic consequences of sleep disruption in healthy adults, with context for how observed changes may be relevant to critically ill populations.KeywordsSleepCircadian rhythmSleep deprivationInadequate sleepSleep insufficiencySleep lossSleep fragmentation
... Human beings sleep at least a quarter of their lifetime. During sleep, learned knowledge is stored in the brain, damaged muscles recover, and cognitive ability is maintained, simultaneously [1][2][3]. Hence, the processes of learning, recovery, and cognition can be disturbed by sleep deprivation resulting from sleep disorders. More seriously, sleep disorders can induce various diseases, including hypertension, coronary disease, diabetes, and cardiac ischemia [4,5]. ...
Article
Full-text available
Daily sleep monitoring is limited by the needs for specialized equipment and experts. This study combines a mask-shaped triboelectric nanogenerator (M-TENG) and machine learning for facile daily sleep monitoring without the specialized equipment or experts. The fabricated M-TENG demonstrates its excellent ability to detect respiration, even distinguishing oral and nasal breath. To increase the pressure sensitivity of the M-TENG, the reactive ion etching is conducted with different tilted angles. By investigating each surface morphology of the polytetrafluoroethylene films according to the reactive ion etching with different tilted angles, the tilted angle is optimized with the angle of 60° and the pressure sensitivity is increased by 5.8 times. The M-TENG can also detect changes in the angle of head and snoring. Various sleep stages can be classified by their distinctive electrical outputs, with the aid of a machine learning approach. As a result, a high averaged-classification accuracy of 87.17% is achieved for each sleep stage. Experimental results demonstrate that the proposed combination can be utilized to monitor the sleep stage in order to provide an aid for self-awareness of sleep disorders. Considering these results, the M-TENG and machine learning approach is expected to be utilized as a smart sleep monitoring system in near future.
... Sleep affects cognitive and immunological functions (Krueger et al. 2016) and tissue repair (Dattilo et al. 2011). For athletes, adequate sleep is essential for optimal performance (Watson 2017), muscle health and injury prevention Silva et al. 2020). ...
Article
This study aims to describe the athletes' sleep regularity using the Sleep Regularity Index (SRI) and determine whether factors, such as sex, competitive level and sport type, could affect the sleep/wake rhythm. It is a descriptive, cross-sectional study consisting of 172 athletes (25 ± 7 y old; 45 women). Seventy-three competed in team sports and 99 in individual sports. Furthermore, 56 competed in the international level, 95 in the national and 21 in the regional. We recorded the SRI values for at least 5 d via continuous actigraphy. We recorded a mean SRI value of 73 ± 12. We found no significant differences between athletes' sleep parameters in relation to sleep regularity. Furthermore, SRI data showed no correlations (Spearman's ρ) with sleep parameters, bed time and wake time. Female athletes (p = 0.001) and individual sport athletes (p = 0.001) reported better sleep regularity than their counterparts. International-level athletes reported better sleep regularity than those in other competitive levels (national: p = 0.001; regional: p = 0.024). Our study showed that international level athletes, female athletes and individual sport athletes reported better sleep regularity. Additionally, SRI data showed no correlation with athletes' sleep parameters, bed and wake time.
... 30 IGF-1 is an anabolic hormone that is responsible for protein synthesis and the maintenance of muscle mass. [33][34][35] Previous studies have found that IGF-1 is rapidly reduced under conditions of sleep deprivation. 32 In a study by Luboshitzky et al., sleep deprivation is associated with changes in the pattern of the rhythmic section of anabolic hormones. ...
Article
Full-text available
Background: Malaysia has the highest prevalence of obesity among Southeast Asian countries, and the current number is expected to increase further. In particular, the rate of obesity is reportedly increasing among females and young adults in Malaysia. Modern lifestyle habits, which include night eating and poor sleep quality, have been shown to increase the risk of obesity and high body fat. This study aims to determine the link between female university students’ body composition and their night eating habits and sleep quality. Methods: Body composition was measured using a Bioelectrical Impedance Analysis (BIA) analyzer. Night eating syndrome and sleeping pattern and quality were determined using the Night Eating Questionnaire (NEQ) and the Pittsburgh Sleep Quality Index (PSQI), respectively. Results: A total of 112 female students participated in this study, the majority (66.1%) of whom were categorized as having normal weight. Their body fat percentages (28.0 ± 6.1) were found to be lower than the standard value for Asian women. Most of the subjects were categorized as having normal night eating (93.8%) and poor sleep (76.8%) patterns. The correlation analysis results indicated significant relationships between sleep quality and night eating habit and body weight. Furthermore, analysis using binary logistic regression showed a protective relationship between muscle mass and sleeping habit. Conclusions: This study showed that the majority of the university students had poor sleep quality. This is an alarming finding. Therefore, further investigations on factors related to poor sleep quality among young adults are required.
... Findings also revealed that, among males, for each one-unit increase in overall stress, sleep duration increased by 22 min. It is surprising that overall stress was not similarly associated with sleep duration in females, as feeling more "worn-out" and "physically exhausted" (i.e., having higher overall stress) may be expected to increase sleep need, as sleep is thought to facilitate recovery partly by replenishing energy stores (Scharf et al., 2008), and promoting tissue repair (Chennaoui et al., 2016;Dattilo et al., 2011). Across all athletes, for each one-unit increase in overall stress, WASO increased by 8 min, which may reflect an anticipatory stress response prior to competition (Van Paridon et al., 2017). ...
Article
This study examined sex differences among endurance athletes in pre-race relationships between sleep, and perceived stress and recovery. Thirty-six athletes completed the Short Recovery and Stress Scale, and had sleep monitored via actigraphy, over four consecutive days prior to an ultra-marathon. Overall, compared with males, females had shorter wake after sleep onset (mean ± SD, 50 ± 23 vs 65 ± 23 min, p = .04) and lower emotional balance (3.9 ± 1.1 vs 4.8 ± 1.1 arbitrary units, p = .001). The day before the race, females scored higher for all stress-related items (p < 0.05). Among females, higher scores for emotional balance (β = -31 min, p = .01) and negative emotional state (β = -21 min, p < .001) were associated with reduced sleep duration. Among males, higher scores for overall stress were associated with increased sleep duration (β = 22 min, p = .01). Across all athletes, longer sleep duration was associated with improved overall recovery (β = 0.003 arbitrary units, p = .02). Females experienced greater pre-race stress than males, and their sleep duration was associated with emotional factors. The SRSS may help identify female athletes at risk of sleep difficulties prior to competition.
... There is time for everything. When you work late till night for whatever reasons, ultimately, there will be a time when your body will start showing negative effects [10]. ...
Article
Full-text available
Sleep is the most important but often neglected element of an individual’s overall health and well-being. Lack of sleep or poor sleep can adversely affect health in an individual and lead to various diseases. At the same time, sleep problems are not uncommon among students. The factors leading to poor sleep among management students who have a comparatively tight schedule are still unclear. The paper aims to understand the factors leading to poor sleep among management students. The study has been focused on the management students (MBA’s) studying in the different management colleges of the state of Maharashtra. A total of 297 management students were surveyed. Apart from factor analysis, the Kessler distress scale was used for Measuring Psychological distress.52% of the respondents fell in the category of likely to have a mental disorder. Managements can draw inference from this and implement strategies to make sure this number reduces.
... Sleep is essential for adequate recovery from exercise practice, especially at high intensity-levels. Insufficient sleep seems to impair the secretion of anabolic hormones such as testosterone and growth hormone and favor the secretion of catabolic hormones such as cortisol and myostatin, predisposing athletes to musculoskeletal injuries (Dattilo et al., 2011;Sousa et al., 2020). Therefore, sleep deficit has been associated with an increased risk of injury in abled-bodied athletes in different age groups (Milewski et al., 2014;Silva et al., 2019). ...
Article
Objectives To evaluate sleep characteristics and investigate the relationship of sleep with injuries and illnesses in Paralympic athletes. Design Cross-sectional. Setting Sports Training Center. Participants 20 Paralympic athletes of athletics, swimming, and powerlifting. Outcomes Injury and illnesses were recorded during the sports season through the Oslo Sports Trauma Research Center questionnaire (OSTRC-BR). Sleep-wake pattern was monitored for 2 weeks using actigraphy. Chronotype, sleep quality, sleep behavior, and sleep complaints were cross-sectionally collected. Results Poor sleep quality and poor sleep behavior were highly prevalent. The mean total sleep time was 6.57 ± 49.91. Duration of naps (r= −0.46; p=0.04) was associated with occurrence of health problems; frequency of insomnia (r= 0.51; p= 0.02), Pittsburgh Sleep Quality Index score (r= 0.45; p=0.04), and frequency of awakenings at night (r= 0.58; p= 0.01) were associated with severity of health problems; frequency of movements during sleep was associated with OSTRC-BR cumulative score (r= 0.58; p=0.00); and frequency of nightmares was associated with OSTRC mean score. Conclusions Paralympic athletes tend to report poor sleep quality, have poor sleep behavior and sleep less than the recommended. Insomnia symptoms, awakenings at night, movements during sleep and poor sleep quality were associated with the occurrence and/or severity of health problems.
... This is largely due to the regenerative and repair processes that occur to both the body and the brain during rapid eye movement (REM) and non-rapid eye movement (NREM) sleep 2 . Indeed, from a physical perspective, one of the important hormones responsible for muscle growth and repair, growth hormone, is mainly secreted at night, during NREM slow wave sleep 9,10 . Poor sleep also disrupts growth and repair of cells 10 and individuals who sleep less may have impaired physical performance when compared to individuals who obtain a greater amount of sleep 11,12 . ...
Article
Full-text available
Objectives: There is limited large-scale data on maladaptive sleep practices in elite adult athletes and their influence on sleep characteristics. This study aimed to identify differences in sleep behaviours between individual and team-sport athletes using two sleep questionnaires. Material and methods: 407 (237 male, 170 female) elite adult athletes across sixteen sports (9 individual-sports, 7 team-sports) completed the Athlete Sleep Behavior Questionnaire (ASBQ) and the Pittsburgh Sleep Quality Index (PSQI). Results: Individual-sport athletes reported greater total sleep time and higher sleep efficiency than team-sport athletes (p<0.05, d=0.28-0.29). There were no differences between global scores for the PSQI, however, there was a difference between global scores for the ASBQ as well as multiple individual items from both questionnaires (p<0.05), indicating poorer behaviours in team-sport athletes. Discussion: Team-sport athletes displayed more maladaptive pre-sleep behaviours and poorer sleep characteristics than individual-sport athletes.
Article
Full-text available
Introduction: Sleep is a physiologically important process that has profound impacts on physical and mental health of individuals. The aim of this study was to investigate the effect of 30 hour of sleep deprivation on fitness factors related motor skill such as: speed, power, balance, agility, visual reaction time and neuromuscular coordination on active male college. Methods: the present study was a semi-experimental which used pre-test and post-test design. 32 active male from the university of Tabriz (age 22±1 years, Height 1.78±0.06 meter, weight 72.4±7.3 kilograms and BMI 22.7±0.4) were randomly divided into Two groups of 16 people (control and sleepless) groups. After the first day at 12:00 pm, fitness tests administered to both groups, Subjects rested for three days and from 6:00 am to 12:00 am on the fourth day after the group spent a sleepless period. Then again at 12:00 pm on the fifth day of every fitness test, both groups were performed. For statistical analysis software SPSS17 and independent t-test was used. Results: 30 hours of sleep deprivation significantly increase velocity of 36 m test time, timing agility and reaction time (P<0/05) and significantly decrease Sargent jump height, static balance, and throw darts scores (P<0/05) subjects. Conclusions: 30 hours of sleep deprivation can cause reduction in physical performance. Therefore, athletes and non-athletes should get enough sleep to prevent the performance decline in activities that need speed, power, balance, agility, reaction time and neuromuscular coordination they need. Key words: sleep deprivation, physical fitness factors, Active male college
Article
Full-text available
Introduction: Because sleep effects on most of the functions of daily life, it is an important aspect of life. Purpose: The aim of this study was to investigate the effect of 12 hours of sleep deprivation (30 hours wake) on health-related fitness factors including: muscular strength, muscular endurance, cardiovascular endurance, flexibility and body composition in active male college. Methodology: thirthy two active male college, with range of age 20 to 26 years, Height 1.64 to 1.90 meter, weight 58 to 85 kilograms and BMI 18.9 to 27.4 kg/m2, were randomly divided into two groups of insomnia (n=16) and control (n=16). After the first day fitness tests administered to both groups, Subjects rested for three days and from 6:00 am fourth day to 12:00 am on the after day the experimental group spent a sleepless period. Then again on the fifth day both groups were performed of every fitness test. Average and range of differences were analyzed using independent t-test and software SPSS17. Results: After 12 hours of sleep deprivation, muscular endurance (P<0.003) subjects had significantly decrease, While had no significant change on muscular strength, cardiovascular endurance, flexibility and body fat of sleepless athletes (P>0.05). Conclusion: 12 hours of sleep deprivation cannot much cause reduction in physical performance. Therefore, athletes and non-athletes should get enough sleep at night to prevent performance decline in activities that require muscular endurance. Keywords: sleep deprivation, physical fitness factors, Active male college.
Article
Full-text available
Alpine skiing is among the most demanding sporting activities in terms of physical effort and mental workload. The aim of the study was to compare sleep quality and chronotype distribution between 84 highly trained alpine skiers and a control sample of 84 non-athletes matched by age and sex ratio. Quality of sleep was assessed by the Pittsburgh Quality of Sleep Index (PSQI), and chronotype was assessed by the Morningness-Eveningness Questionnaire (MEQ). Additional questions assessed sleep management during training or competitions. The results showed a marked skewed chronotype distribution towards morningness in alpine skiers (52.4% morning type, 42.8% intermediate, and 4.8% evening type) in comparison to the control group. The midpoint of sleep was significantly anticipated among alpine skiers. Differently from the previous literature that showed poor sleep quality and quantity in competitive athletes, the quality and quantity of sleep in alpine skiers was within the normal range in all the PSQI subcomponents.
Article
Full-text available
Sleep is essential for our health. Short sleep is known to increase disease risks via imbalance of intestinal microbiota, dysbiosis. However, mechanisms by which short sleep induces dysbiosis remain unknown. Small intestinal Paneth cell regulates the intestinal microbiota by secreting antimicrobial peptides including α-defensin, human defensin 5 (HD5). Disruption of circadian rhythm mediating sleep-wake cycle induces Paneth cell failure. We aim to clarify effects of short sleep on HD5 secretion and the intestinal microbiota. Fecal samples and self-reported sleep time were obtained from 35 healthy middle-aged Japanese (41 to 60-year-old). Shorter sleep time was associated with lower fecal HD5 concentration (r = 0.354, p = 0.037), lower centered log ratio (CLR)-transformed abundance of short-chain fatty acid (SCFA) producers in the intestinal microbiota such as [Ruminococcus] gnavus group (r = 0.504, p = 0.002) and Butyricicoccus (r = 0.484, p = 0.003), and lower fecal SCFA concentration. Furthermore, fecal HD5 positively correlated with the abundance of these genera and SCFA concentration. These findings suggest that short sleep relates to disturbance of the intestinal microbiota via decreased HD5 secretion.
Article
Background Although studies have demonstrated associations between sleep quality (SQ) and grip strength (GS) in older adults, the direction and underlying mechanisms of this relationship are yet to be better delineated. We aimed to longitudinally investigate the bidirectional association between SQ and GS and the mediating role of depression in this association. Methods Based on two nationally representative samples with people aged ≥ 50 years from the China Health and Retirement Longitudinal Study (CHARLS; 4,200 participants) and English Longitudinal Study of Ageing (ELSA; 5,922 participants), cross-lagged panel models were employed to examine the potential bidirectional relationships between objectively measured GS and self-reported SQ. Results We observed a GS-SQ bidirectional association dominated by GS. After adjusting for potential confounders, a higher GS at T1 predicted better SQ at T2 (ELSA: β = 0.075; CHARLS: β = 0.104, P < 0.001) and vice versa (ELSA: β = 0.034; CHARLS: β = 0.030, P < 0.01). Moreover, depression partially mediated the impact of GS on subsequent SQ (ELSA, indirect effect: 0.0057, 95% CI: [0.0035-0.0084]; CHARLS, indirect effect: 0.0086, 95% confidence interval: [0.0051, 0.0131]), but not vice versa. Conclusions The results regarding data from both cohorts consistently supported a bidirectional association between GS and SQ and the mediating role of depression in the dominant pathway of this bidirectional relationship. Older adults with a low GS should be made aware of a potentially vicious cycle related to depression that can affect their sleep. Regular screening for depression may help to break this cycle.
Article
Objective: Poor sleep quality, such as nocturnal arousal and sleep inefficiency, is associated with frailty and sarcopenia. Herein, we evaluated the relationship between poor sleep quality and locomotive syndrome (LS), a motor organ dysfunction common among community-dwelling middle-aged and older women. Methods: Participants comprised 2246 Japanese middle-aged and older women. LS was classified into stages LS-1, LS-2, and LS-3 (from least to most severe) according to results on the stand-up test, two-step test, and 25-question Geriatric Locomotive Function Scale. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Results: PSQI scores were significantly higher in the LS group than in the non-LS group (P < .001). Multivariate logistic regression analyses adjusted for potential confounders identified poor sleep quality as an independent factor of LS (OR 1.59 [95% CI 1.30-1.93], P < .001). Similar results were observed in the sensitivity analysis in postmenopausal women. LS and trouble sleeping because of pain showed stepwise association in all LS stages. Conclusions: Poor sleep quality was independently associated with LS among community-dwelling middle-aged and older women. As the stage of LS progressed, the proportion of women with poor sleep quality increased significantly.
Article
Purpose: This cross-sectional study aimed to evaluate whether weekday sleep duration, weekend catch-up sleep, and risk of obstructive sleep apnea are individually and in combination associated with handgrip strength. Methods: Data from the Korea National Health and Nutrition Examination Survey 2019, including weekday sleep duration, weekend catch-up sleep, STOP-BANG scores, relative handgrip strength (handgrip strength divided by body mass index), and confounding factors (sociodemographic factors, health behaviors, and health and nutritional status), were evaluated in 3678 Korean adults aged 40 to 80 years. Adequate (vs. inadequate) sleep parameters were defined as weekday sleep duration (6-7 vs. ≤ 5 or ≥ 8 h), weekend catch-up sleep (presence vs. absence), and risk of obstructive sleep apnea (low vs. high based on STOP-BANG scores). Sex-specific quintiles of relative handgrip strength were categorized as high (highest 5th quintile) or low (lower 1st to 4th quintiles). A complex-sample logistic regression analysis was performed. Results: After adjusting for other sleep parameters and confounding variables, each adequate sleep parameter individually and collectively was associated with high relative handgrip strength (adjusted odds ratios [95% confidence interval], 1.43 [1.09, 1.89] for 6-7 h weekday sleep duration; 1.44 [1.10, 1.90] for low risk of obstructive sleep apnea; 1.72 [1.23, 2.40] for any two parameters; 1.81 [1.18, 2.79] for all parameters). The combination of adequate weekend catch-up sleep and obstructive sleep apnea risk had the highest odds ratio for high relative handgrip strength (2.36 [1.45, 3.83]). Conclusions: Adequate weekday sleep duration, weekend catch-up sleep, and low obstructive sleep apnea risk were individually and in combination associated with high handgrip strength.
Chapter
Sleep problems are a common comorbidity in children with neurodevelopmental disorders (NDD), which can result in a number of deleterious effects for both the child and their family. Understanding what sleep is, how it is regulated, and how sleep physiology can differ for children with NDD is important to inform assessment and treatment. Both genetic and environmental factors are known to contribute to sleep problems; therefore, this chapter will consider a biopsychosocial framework when describing the etiology of sleep disorders in children with NDD. A number of sleep assessment measures are used to identify and diagnose sleep disorders as well as to monitor the efficacy of interventions. These include subjective measures such as a sleep diary and questionnaires, and objective measures such as actigraphy and polysomnography. Treatment of sleep disorders can vary depending on the specific diagnosis, as well as any other comorbid disorders the child may have. Insomnia is the most common sleep disorder in pediatric populations, and therefore, this chapter describes the recommended stepped care approach to the treatment of insomnia in children with NDD. This stepwise approach includes psychoeducation, the implementation of healthy sleep practices, behavioral and cognitive sleep interventions, and lastly pharmacotherapy. Moving forward, a transdiagnostic approach to treatment of sleep problems should be considered, whereby the same basic treatment principles are applied across disorders without tailoring specifically to each individual NDD diagnosis.
Article
Objective: This cross-sectional study examined the relationship between body composition and physical and mental symptom severity in middle-aged women. Methods: The first-visit records of 554 women aged 40-64 years were examined. The fat mass index (FMI) and lean mass index (LMI) were defined as fat mass and lean mass divided by the height squared, respectively. The participants were divided into two groups according to their median values. Results: The only menopausal symptom with significantly different severity between the high and low FMI groups was hot flashes (HF) on the Menopausal Health-Related Quality of Life Questionnaire. The factors associated with severe HF were investigated using multiple logistic regression analysis. After adjusting, the FMI (kg/m2) was independently positively associated with severe HF (odds ratio, 1.08; 95% confidence interval, 1.02-1.15). Insomnia was the only menopausal symptom with significantly different severity between the LMI groups (defined as Athens Insomnia Scale score ≥10 points). The factors associated with moderate-to-severe insomnia were investigated using multiple logistic regression analysis. After adjusting, the LMI (kg/m2) was independently negatively associated with moderate-to-severe insomnia (odds ratio, 0.72; 95% confidence interval, 0.55-0.94). Conclusions: The FMI was positively associated with severe HF, whereas the LMI was negatively associated with moderate-to-severe insomnia in middle-aged women.
Article
Purpose: This study aimed to examine the association between sleep duration and quality and sarcopenia, assessed by factors such as low muscle mass (LMM), low muscle strength (LMS), and low physical performance (LPP) among older community-dwellers in Japan. Methods: In this cross-sectional study, a total of 2,069 (men, 902; women, 1,167) participants aged 65 to 80 years were included. Sarcopenia and each low physical function were defined using the definitions of the Asian Working Groups of Sarcopenia 2019. Sleep duration was stratified into three categories: short sleep (<6 h), normal sleep (6-8 h), and long sleep (>8 h). Sleep quality was classified into two groups based on 8-item Athens Insomnia Scale score: insomnia (≥6), and non-insomnia (<6). We analyzed the association between sleep parameters and sarcopenia, including low physical functions, by logistic regression analysis. Results: Compared to normal sleepers, long sleepers had a positive association with sarcopenia (odds ratio [OR] 2.11, 95% confidence interval [CI] 1.25-3.58). In particular, long sleep was strongly associated with LMS (OR 1.77, 95%CI 1.07-2.94) and LPP (OR 1.90, 95%CI 1.25-2.88). On the other hand, poor sleep quality was not associated with sarcopenia in long sleepers, but in normal sleepers. Conclusions: Long sleep was associated with sarcopenia, including LMS and LPP. However, in long sleepers, insomnia was not associated with sarcopenia or any of its components.
Article
Full-text available
Little cross-sectional and even less longitudinal research has been conducted on sleep quality and well-being in junior elite athletes. This study analyzed the relationship between subjective sleep quality and both psychological and physiological well-being in junior elite athletes using both a cross-sectional ( N = 625 athletes; 49.9 % = female; M = 16.4 years, SD = 3.5 years) and a longitudinal approach ( n = 79; 44.3 % = female; M = 16.4 years, SD = 3.5 years) over a period of M = 1.66 years ( SD = 0.87 years). The results demonstrated that both samples showed that subjective sleep quality is correlated with well-being in junior elite athletes. In addition, the results showed that athletes of prepuberty age reported significantly better sleep quality than athletes during and after puberty, and that the relationship between sleep quality and psychological well-being is stronger in female junior athletes than in male athletes. This study emphasizes the need to ensure quality sleep in junior elite athletes.
Article
Background: Military personnel must maintain physical performance despite exposure to operational stressors such as sleep loss, caloric restriction and high cognitive load. Habitual sleep and specific sleep features are positively associated with fitness and may contribute to physical performance in operational settings. Further, by affecting muscle recovery, sleep may contribute to the ability to maintain performance across multiple days of exposure to operational stressors. Objectives: We examined the role of individual differences in baseline sleep on baseline physical performance and on change in physical performance throughout exposure to simulated military operational stress (SMOS). Methods: Military personnel (36 male, 9 female, 26.3 ± 5.3 years) completed a 5-day SMOS protocol during which they completed a tactical mobility test daily. Sleep questionnaires were administered at intake and sleep was monitored each night with polysomnography. Lasso regressions were used to identify meaningful predictors of physical performance at baseline and of change in physical performance across SMOS. Results: Better aerobic fitness, lower daytime sleepiness (Epworth Sleepiness Scale), and lower absolute slow wave activity (0.5-4 Hz) predicted better physical performance at baseline (66.1% of variance explained), but did not relate to changes in performance. Conclusions: Collectively, higher daytime sleepiness and slow wave activity may reflect more chronic exposure to insufficient sleep and higher baseline sleep drive, which in turn led to compromised physical performance. The findings suggest that low self-report sleepiness and low objective slow wave activity may reflect two quantifiable markers of healthy sleep behaviors that have implications for operational performance.
Article
Context: Sleep serves many important functions for athletes, particularly in the processes of learning, memory, recovery, and cognition. Objectives: Define the sleep parameters of Paralympic athletes and identify the instruments used to assess and monitor sleep Paralympic athletes. Evidence acquisition: This systematic review was carried out based on the PRISMA guidelines. The survey was conducted in April 2020, the searches were carried out again in September 2021 to check whether there were new scientific publications in the area of sleep and Paralympic sport, searches were performed in the following databases: PubMed, Web of Science, Scopus, SPORTDiscus, Virtual Health Library (BIREME), and SciELO. This systematic review has included studies that investigated at least one of the following sleep parameters: total sleep time, sleep latency, sleep efficiency, number of awakenings, quality of sleep, daytime sleepiness, and chronotype; the participants were comprised of athletes with disabilities. Studies published at any time in English, Portuguese, and Spanish, were included. Evidence synthesis: Data extraction and study selection were performed by 2 researchers independently, and a third author was consulted as necessary. The search returned a total of 407 studies. Following the screening based on exclusion and inclusion criteria, a total of 13 studies were considered. Paralympic athletes have a low amount (7.06 h) of sleep with poor quality and sleep latency (28.05 min), and 57.2% have daytime sleepiness, with the majority belonging to the indifferent chronotype (53, 5%). Moreover, 11 studies assess sleep using subjective instruments (questionnaires), and 2 studies used an objective instrument (actigraphy). Conclusions: Sleep disorders are common among Paralympic athletes, poor sleep quality and quantity, and high rates of daytime sleepiness. Subjective methods are most commonly used to assess sleep.
Article
Sleep is important for cognitive and physical performance. Sleep deprivation not only affects neural functions but also results in muscular fatigue. A good night's sleep reverses these functional derangements caused by sleep deprivation. The role of sleep in brain function has been extensively studied. However, its role in neuromuscular junction or skeletal muscle morphology is sparsely addressed although skeletal muscle atonia and suspended thermoregulation during rapid eye movement sleep possibly provide a conducive environment for the muscle to rest and repair; somewhat similar to slow-wave sleep for synaptic downscaling. In the present study, we have investigated the effect of 24 h sleep deprivation on the neuromuscular junction morphology and neurochemistry using electron microscopy and immunohistochemistry in the rat soleus muscle. Acute sleep deprivation altered synaptic ultra-structure viz. mitochondria, synaptic vesicle, synaptic proteins, basal lamina, and junctional folds needed for neuromuscular transmission. Further acute sleep deprivation showed the depletion of the neurotransmitter acetylcholine and the overactivity of its degrading enzyme acetylcholine esterase at the neuromuscular junction. The impact of sleep deprivation on synaptic homeostasis in the brain has been extensively reported recently. The present evidence from our studies shows new information on the role of sleep on neuromuscular junction homeostasis and its functioning.
Article
Full-text available
Background Elite rugby players experience poor sleep quality and quantity. This lack of sleep could compromise post-exercise recovery. Therefore, it appears central to encourage sleep in order to improve recovery kinetics. However, the effectiveness of an acute ergogenic strategy such as sleep extension on recovery has yet to be investigated among athletes. Aim To compare the effects of a single night of sleep extension to an active recovery session (CON) on post-exercise recovery kinetics. Methods In a randomised cross-over design, 10 male rugby union players participated in two evening training sessions (19:30) involving collision activity, 7-days apart. After each session, participants either extended their sleep to 10 hours or attended an early morning recovery session (07:30). Prior to (PRE), immediately after (POST 0 hour [h]), 14h (POST 14) and 36h (POST 36) post training, neuromuscular, perceptual and cognitive measures of fatigue were assessed. Objective sleep parameters were monitored two days before the training session and over the two-day recovery period. Results The training session induced substantial decreases in countermovement jump mean power and wellness across all time points, while heart rate recovery decreased at POST 0 in both conditions. Sleep extension resulted in greater total sleep time (effect size [90% confidence interval]: 5.35 [4.56 to 6.14]) but greater sleep fragmentation than CON (2.85 [2.00 to 3.70]). Between group differences highlight a faster recovery of cognitive performance following sleep extension (-1.53 [-2.33 to -0.74]) at POST 14, while autonomic function (-1.00 [-1.85 to -0.16]) and upper-body neuromuscular function (-0.78 [-1.65 to 0.08]) were better in CON. However, no difference in recovery status between groups was observed at POST 36. Conclusion The main finding of this study suggests that sleep extension could affect cognitive function positively but did not improve neuromuscular function the day after a late exercise bout.
Article
Background Daytime napping on match-day is a strategy used by athletes to alleviate sleep debt or to avoid boredom. However, the utilization of pre-match napping and its effect on self-rated performance has not been evaluated in professional Rugby athletes. Methods Over a 17-match season, 30 professional Rugby Union athletes (mean ± SD: 23 ± 3 y) completed a weekly questionnaire on their daytime napping practices on match day. Questions included whether they took a nap, the duration of nap, their mood state upon waking and, their perceived performance during the subsequent match. Additionally, three team coaches evaluated the match performance of each participant. Finally, each participant was asked a questionnaire focusing on their napping preferences and individual habits of match-day napping at the conclusion of the season. Results Pre-match naps were used by 86% of athletes, with an average nap duration of 32 ± 19 min. A significantly greater number of naps were taken during away matches compared to home matches (60% vs. 40%, p < 0.01). Of the athletes who napped, 86% chose to nap less than 4 h before kick-off. Furthermore, 87% of athletes who napped on match day reported believing naps helped their match performance. Additionally, the odds of an athlete rating their performance as “good” was increased 6.7 times if they napped and won the match. Conclusion This study highlights that match-day naps are commonly used amongst professional Rugby Union athletes. The results suggest that taking naps before away matches may support self-rated performance amongst Rugby Union athletes.
Article
Full-text available
Sleep loss can modify energy intake and expenditure. To determine whether sleep restriction attenuates the effect of a reduced-calorie diet on excess adiposity. Randomized, 2-period, 2-condition crossover study. University clinical research center and sleep laboratory. 10 overweight nonsmoking adults (3 women and 7 men) with a mean age of 41 years (SD, 5) and a mean body mass index of 27.4 kg/m² (SD, 2.0). 14 days of moderate caloric restriction with 8.5 or 5.5 hours of nighttime sleep opportunity. The primary measure was loss of fat and fat-free body mass. Secondary measures were changes in substrate utilization, energy expenditure, hunger, and 24-hour metabolic hormone concentrations. Sleep curtailment decreased the proportion of weight lost as fat by 55% (1.4 vs. 0.6 kg with 8.5 vs. 5.5 hours of sleep opportunity, respectively; P = 0.043) and increased the loss of fat-free body mass by 60% (1.5 vs. 2.4 kg; P = 0.002). This was accompanied by markers of enhanced neuroendocrine adaptation to caloric restriction, increased hunger, and a shift in relative substrate utilization toward oxidation of less fat. The nature of the study limited its duration and sample size. The amount of human sleep contributes to the maintenance of fat-free body mass at times of decreased energy intake. Lack of sufficient sleep may compromise the efficacy of typical dietary interventions for weight loss and related metabolic risk reduction. National Institutes of Health.
Article
Full-text available
The daily rhythm of cortisol secretion is relatively stable and primarily under the influence of the circadian clock. Nevertheless, several other factors affect hypothalamo-pituitary-adrenal (HPA) axis activity. Sleep has modest but clearly detectable modulatory effects on HPA axis activity. Sleep onset exerts an inhibitory effect on cortisol secretion while awakenings and sleep offset are accompanied by cortisol stimulation. During waking, an association between cortisol secretory bursts and indices of central arousal has also been detected. Abrupt shifts of the sleep period induce a profound disruption in the daily cortisol rhythm, while sleep deprivation and/or reduced sleep quality seem to result in a modest but functionally important activation of the axis. HPA hyperactivity is clearly associated with metabolic, cognitive and psychiatric disorders and could be involved in the well-documented associations between sleep disturbances and the risk of obesity, diabetes and cognitive dysfunction. Several clinical syndromes, such as insomnia, depression, Cushing's syndrome, sleep disordered breathing (SDB) display HPA hyperactivity, disturbed sleep, psychiatric and metabolic impairments. Further research to delineate the functional links between sleep and HPA axis activity is needed to fully understand the pathophysiology of these syndromes and to develop adequate strategies of prevention and treatment.
Article
Full-text available
Glucocorticoids are a well-recognized and common cause of muscle atrophy that can be prevented by testosterone. However, the molecular mechanisms underlying such protection have not been described. Thus, the global effects of testosterone on dexamethasone-induced changes in gene expression were evaluated in rat gastrocnemius muscle using DNA microarrays. Gene expression was analyzed after 7-d administration of dexamethasone, dexamethasone plus testosterone, or vehicle. Dexamethasone changed expression of 876 probe sets by at least 2-fold. Among these, 474 probe sets were changed by at least 2-fold in the opposite direction in the dexamethasone plus testosterone group (genes in opposition). Major biological themes represented by genes in opposition included IGF-I signaling, myogenesis and muscle development, and cell cycle progression. Testosterone completely prevented the 22-fold increase in expression of the mammalian target of rapamycin (mTOR) inhibitor regulated in development and DNA damage responses 1 (REDD1), and attenuated dexamethasone induced increased expression of eIF4E binding protein 1, Forkhead box O1, and the p85 regulatory subunit of the IGF-I receptor but prevented decreased expression of IRS-1. Testosterone attenuated increases in REDD1 protein in skeletal muscle and L6 myoblasts and prevented dephosphorylation of p70S6 kinase at the mTOR-dependent site Thr389 in L6 myoblast cells. Effects of testosterone on REDD1 mRNA levels occurred within 1 h, required the androgen receptor, were blocked by bicalutamide, and were due to inhibition of transcriptional activation of REDD1 by dexamethasone. These data suggest that testosterone blocks dexamethasone-induced changes in expression of REDD1 and other genes that collectively would otherwise down-regulate mTOR activity and hence also down-regulate protein synthesis.
Article
Full-text available
Compared to a few decades ago, adults, as well as children, sleep less. Sleeping as little as possible is often seen as an admirable behavior in contemporary society. However, sleep plays a major role in neuroendocrine function and glucose metabolism. Evidence that the curtailment of sleep duration may have adverse health effects has emerged in the past 10 years. Accumulating evidence from both epidemiologic studies and well-controlled laboratory studies indicates that chronic partial sleep loss may increase the risk of obesity and weight gain. The present chapter reviews epidemiologic studies in adults and children and laboratory studies in young adults indicating that sleep restriction results in metabolic and endocrine alterations, including decreased glucose tolerance, decreased insulin sensitivity, increased evening concentrations of cortisol, increased levels of ghrelin, decreased levels of leptin and increased hunger and appetite. Altogether, the evidence points to a possible role of decreased sleep duration in the current epidemic of obesity. Bedtime extension in short sleepers should be explored as a novel behavioral intervention that may prevent weight gain or facilitate weight loss. Avoiding sleep deprivation may help to prevent the development of obesity, particularly in children.
Article
Full-text available
Sleep deprivation is associated with considerable social, financial, and health-related costs, in large measure because it produces impaired cognitive performance due to increasing sleep propensity and instability of waking neurobehavioral functions. Cognitive functions particularly affected by sleep loss include psychomotor and cognitive speed, vigilant and executive attention, working memory, and higher cognitive abilities. Chronic sleep-restriction experiments--which model the kind of sleep loss experienced by many individuals with sleep fragmentation and premature sleep curtailment due to disorders and lifestyle--demonstrate that cognitive deficits accumulate to severe levels over time without full awareness by the affected individual. Functional neuroimaging has revealed that frequent and progressively longer cognitive lapses, which are a hallmark of sleep deprivation, involve distributed changes in brain regions including frontal and parietal control areas, secondary sensory processing areas, and thalamic areas. There are robust differences among individuals in the degree of their cognitive vulnerability to sleep loss that may involve differences in prefrontal and parietal cortices, and that may have a basis in genes regulating sleep homeostasis and circadian rhythms. Thus, cognitive deficits believed to be a function of the severity of clinical sleep disturbance may be a product of genetic alleles associated with differential cognitive vulnerability to sleep loss.
Article
Full-text available
Sleep comprises approximately one-third of a person's lifetime, but its impact on health and medical conditions remains partially unrecognized. The prevalence of sleep disorders is increasing in modern societies, with significant repercussions on people's well-being. This article reviews past and current literature on the paradoxical sleep deprivation method as well as data on its consequences to animals, ranging from behavioral changes to alterations in the gene expression. More specifically, we highlight relevant experimental studies and our group's contribution over the last three decades.
Article
Full-text available
Cortisol, urea, glucose, electrolytes, and other compounds were measured in five consecutive 24 h urine collections during a 72 h sleep deprivation study in six young men. Urine was collected during a 24 h predeprivation day, 3 days of sleep deprivation, and a recovery day. Whereas urinary cortisol decreased only slightly, marked changes in other urinary constituents were observed. During sleep deprivation, urinary urea rose markedly, glucose decreased, and urinary electrolytes decreased. These data indicate that sleep deprivation under ad lib food and water conditions can cause disturbances in normal metabolism.
Article
Full-text available
Skeletal muscles adapt to changes in their workload by regulating fibre size by unknown mechanisms. The roles of two signalling pathways implicated in muscle hypertrophy on the basis of findings in vitro, Akt/mTOR (mammalian target of rapamycin) and calcineurin/NFAT (nuclear factor of activated T cells), were investigated in several models of skeletal muscle hypertrophy and atrophy in vivo. The Akt/mTOR pathway was upregulated during hypertrophy and downregulated during muscle atrophy. Furthermore, rapamycin, a selective blocker of mTOR, blocked hypertrophy in all models tested, without causing atrophy in control muscles. In contrast, the calcineurin pathway was not activated during hypertrophy in vivo, and inhibitors of calcineurin, cyclosporin A and FK506 did not blunt hypertrophy. Finally, genetic activation of the Akt/mTOR pathway was sufficient to cause hypertrophy and prevent atrophy in vivo, whereas genetic blockade of this pathway blocked hypertrophy in vivo. We conclude that the activation of the Akt/mTOR pathway and its downstream targets, p70S6K and PHAS-1/4E-BP1, is requisitely involved in regulating skeletal muscle fibre size, and that activation of the Akt/mTOR pathway can oppose muscle atrophy induced by disuse.
Article
Full-text available
Myostatin (MSTN), a transforming growth factor (TGF)-beta superfamily member, has been shown to negatively regulate muscle growth by inhibiting muscle precursor cell proliferation. Here, we stably transfected C(2)C(12) cells with mouse MSTN cDNA to investigate its possible role in myoblast differentiation. We found that MSTN cDNA overexpression reversibly inhibits the myogenic process by downregulating mRNA levels of the muscle regulatory factors myoD and myogenin, as well as the activity of their downstream target creatine kinase. Taking into consideration that MSTN expression during development is restricted to muscle, our results suggest that MSTN probably regulates myogenic differentiation by an autocrine mechanism.
Article
Full-text available
Myostatin, a negative regulator of myogenesis, is shown to function by controlling the proliferation of myoblasts. In this study we show that myostatin is an inhibitor of myoblast differentiation and that this inhibition is mediated through Smad 3. In vitro, increasing concentrations of recombinant mature myostatin reversibly blocked the myogenic differentiation of myoblasts, cultured in low serum media. Western and Northern blot analysis indicated that addition of myostatin to the low serum culture media repressed the levels of MyoD, Myf5, myogenin, and p21 leading to the inhibition of myogenic differentiation. The transient transfection of C(2)C(12) myoblasts with MyoD expressing constructs did not rescue myostatin-inhibited myogenic differentiation. Myostatin signaling specifically induced Smad 3 phosphorylation and increased Smad 3.MyoD association, suggesting that Smad 3 may mediate the myostatin signal by interfering with MyoD activity and expression. Consistent with this, the expression of dominant-negative Smad3 rescued the activity of a MyoD promoter-reporter in C(2)C(12) myoblasts treated with myostatin. Taken together, these results suggest that myostatin inhibits MyoD activity and expression via Smad 3 resulting in the failure of the myoblasts to differentiate into myotubes. Thus we propose that myostatin plays a critical role in myogenic differentiation and that the muscular hyperplasia and hypertrophy seen in animals that lack functional myostatin is because of deregulated proliferation and differentiation of myoblasts.
Article
Full-text available
Muscle growth results from a set of complex processes including myogenic transcription factor's expression and activity, cell cycle withdrawal, myoblast fusion in myotubes, and acquisition of an apoptosis-resistant phenotype. Myostatin, a member of the TGFbeta family, described as a strong regulator of myogenesis in vivo Nature 387 (1997), 83; FEBS Lett. 474 (2000), 71 is upregulated during in vitro differentiation Biochem. Biophys. Res. Commun. 280 (2001), 561. To improve characterization of myostatin's myogenic influence, we stably transfected vectors expressing myostatin and myostatin antisense in C2C12 myoblasts. Here, we found that myostatin inhibits cell proliferation and differentiation. Our results also indicate that myogenin is an important target of myostatin. In addition, overexpressed but not endogenous myostatin decreases MyoD protein levels and induces changes in its phosphorylation pattern. We also established that myostatin overexpression reduces the frequency of G0/G1-arrested cells during differentiation. Conversely, inhibition of myostatin synthesis leads to enhanced cell cycle withdrawal and consequently stimulates myoblast differentiation. We examined the expression patterns of the pRb, E2F1, p53, and p21 proteins involved in cell cycle withdrawal. We found that myostatin overexpression increases p21 and p53 expression, as it does accumulation of hypophosphorylated Rb. Interestingly, myostatin overexpression strongly reduced low-mitogen-induced apoptosis, whereas antisense expression induced contrary changes. In conclusion, these data show the influence of overexpressed myostatin on myoblast proliferation, differentiation, and apoptosis is extended to endogenous myostatin. Though some differences in overexpression or inhibition of endogenous myostatin were observed, it appears that myogenin and p21 are essential targets of this growth factor.
Article
Full-text available
Skeletal muscle atrophy attributable to muscular inactivity has significant adverse functional consequences. While the initiating physiological event leading to atrophy seems to be the loss of muscle tension and a good deal of the physiology of muscle atrophy has been characterized, little is known about the triggers or the molecular signaling events underlying this process. Decreases in protein synthesis and increases in protein degradation both have been shown to contribute to muscle protein loss due to disuse, and recent work has delineated elements of both synthetic and proteolytic processes underlying muscle atrophy. It is also becoming evident that interactions among known proteolytic pathways (ubiquitin-proteasome, lysosomal, and calpain) are involved in muscle proteolysis during atrophy. Factors such as TNF-alpha, glucocorticoids, myostatin, and reactive oxygen species can induce muscle protein loss under specified conditions. Also, it is now apparent that the transcription factor NF-kappaB is a key intracellular signal transducer in disuse atrophy. Transcriptional profiles of atrophying muscle show both up- and downregulation of various genes over time, thus providing further evidence that there are multiple concurrent processes involved in muscle atrophy. The purpose of this review is to synthesize our current understanding of the molecular regulation of muscle atrophy. We also discuss how ongoing work should uncover more about the molecular underpinnings of muscle wasting, particularly that due to disuse.
Article
Full-text available
Total sleep deprivation in rodents and in humans has been associated with hyperphagia. Over the past 40 years, self-reported sleep duration in the United States has decreased by almost 2 hours. To determine whether partial sleep curtailment, an increasingly prevalent behavior, alters appetite regulation. Randomized, 2-period, 2-condition crossover clinical study. Clinical Research Center, University of Chicago, Chicago, Illinois. 12 healthy men (mean age [+/-SD], 22 +/- 2 years; mean body mass index [+/-SD], 23.6 +/- 2.0 kg/m2). Daytime profiles of plasma leptin and ghrelin levels and subjective ratings of hunger and appetite. 2 days of sleep restriction and 2 days of sleep extension under controlled conditions of caloric intake and physical activity. Sleep restriction was associated with average reductions in the anorexigenic hormone leptin (decrease, 18%; P = 0.04), elevations in the orexigenic factor ghrelin (increase, 28%; P < 0.04), and increased hunger (increase, 24%; P < 0.01) and appetite (increase, 23%; P = 0.01), especially for calorie-dense foods with high carbohydrate content (increase, 33% to 45%; P = 0.02). The study included only 12 young men and did not measure energy expenditure. Short sleep duration in young, healthy men is associated with decreased leptin levels, increased ghrelin levels, and increased hunger and appetite.
Article
Full-text available
Sleep duration may be an important regulator of body weight and metabolism. An association between short habitual sleep time and increased body mass index (BMI) has been reported in large population samples. The potential role of metabolic hormones in this association is unknown. Study participants were 1,024 volunteers from the Wisconsin Sleep Cohort Study, a population-based longitudinal study of sleep disorders. Participants underwent nocturnal polysomnography and reported on their sleep habits through questionnaires and sleep diaries. Following polysomnography, morning, fasted blood samples were evaluated for serum leptin and ghrelin (two key opposing hormones in appetite regulation), adiponectin, insulin, glucose, and lipid profile. Relationships among these measures, BMI, and sleep duration (habitual and immediately prior to blood sampling) were examined using multiple variable regressions with control for confounding factors. A U-shaped curvilinear association between sleep duration and BMI was observed. In persons sleeping less than 8 h (74.4% of the sample), increased BMI was proportional to decreased sleep. Short sleep was associated with low leptin (p for slope = 0.01), with a predicted 15.5% lower leptin for habitual sleep of 5 h versus 8 h, and high ghrelin (p for slope = 0.008), with a predicted 14.9% higher ghrelin for nocturnal (polysomnographic) sleep of 5 h versus 8 h, independent of BMI. Participants with short sleep had reduced leptin and elevated ghrelin. These differences in leptin and ghrelin are likely to increase appetite, possibly explaining the increased BMI observed with short sleep duration. In Western societies, where chronic sleep restriction is common and food is widely available, changes in appetite regulatory hormones with sleep curtailment may contribute to obesity.
Article
Full-text available
Skeletal muscle atrophy has extreme adverse consequences. Molecular mechanisms that mediate the process of atrophy are not well defined. Recent studies have focused on diverse molecular cascades that control the activation of ubiquitin ligases, indicating that the involvement of the ubiquitin proteasome may be common to a range of atrophic stimuli.
Article
Full-text available
Deficits in daytime performance due to sleep loss are experienced universally and associated with a significant social, financial, and human cost. Microsleeps, sleep attacks, and lapses in cognition increase with sleep loss as a function of state instability. Sleep deprivation studies repeatedly show a variable (negative) impact on mood, cognitive performance, and motor function due to an increasing sleep propensity and destabilization of the wake state. Specific neurocognitive domains including executive attention, working memory, and divergent higher cognitive functions are particularly vulnerable to sleep loss. In humans, functional metabolic and neurophysiological studies demonstrate that neural systems involved in executive function (i.e., prefrontal cortex) are more susceptible to sleep deprivation in some individuals than others. Recent chronic partial sleep deprivation experiments, which more closely replicate sleep loss in society, demonstrate that profound neurocognitive deficits accumulate over time in the face of subjective adaptation to the sensation of sleepiness. Sleep deprivation associated with disease-related sleep fragmentation (i.e., sleep apnea and restless legs syndrome) also results in neurocognitive performance decrements similar to those seen in sleep restriction studies. Performance deficits associated with sleep disorders are often viewed as a simple function of disease severity; however, recent experiments suggest that individual vulnerability to sleep loss may play a more critical role than previously thought.
Article
Full-text available
The TOR (target of rapamycin) pathway is an evolutionarily conserved signaling module regulating cell growth (accumulation of mass) in response to a variety of environmental cues such as nutrient availability, hypoxia, DNA damage and osmotic stress. Its pivotal role in cellular and organismal homeostasis is reflected in the fact that unrestrained signaling activity in mammals is associated with the occurrence of disease states including inflammation, cancer and diabetes. The existence of TOR homologs in unicellular organisms whose growth is affected by environmental factors, such as temperature, nutrients and osmolarity, suggests an ancient role for the TOR signaling network in the surveillance of stress conditions. Here, we will summarize recent advances in the TOR signaling field with special emphasis on how stress conditions impinge on insulin/insulin-like growth factor signaling/TOR signaling.
Article
Full-text available
The mammalian target of rapamycin (mTOR), a critical modulator of cell growth, acts to integrate signals from hormones, nutrients, and growth-promoting stimuli to downstream effector mechanisms involved in the regulation of protein synthesis. Dexamethasone, a synthetic glucocorticoid that represses protein synthesis, acts to inhibit mTOR signaling as assessed by reduced phosphorylation of the downstream targets S6K1 and 4E-BP1. Dexamethasone has also been shown in one study to up-regulate the expression of REDD1 (also referred to RTP801, a novel stress-induced gene linked to repression of mTOR signaling) in lymphoid, but not nonlymphoid, cells. In contrast to the findings of that study, here we demonstrate that REDD1, but not REDD2, mRNA expression is dramatically induced following acute dexamethasone treatment both in rat skeletal muscle in vivo and in L6 myoblasts in culture. In L6 myoblasts, the effect of the drug on mTOR signaling is efficiently blunted in the presence of REDD1 RNA interference oligonucleotides. Moreover, the dexamethasone-induced assembly of the mTOR regulatory complex Tuberin. Hamartin is disrupted in L6 myoblasts following small interfering RNA-mediated repression of REDD1 expression. Finally, overexpression of Rheb, a downstream target of Tuberin function and a positive upstream effector of mTOR, reverses the effect of dexamethasone on phosphorylation of mTOR substrates. Overall, the data support the conclusion that REDD1 functions upstream of Tuberin and Rheb to down-regulate mTOR signaling in response to dexamethasone.
Article
Full-text available
Recent advances in our understanding of both the regulation of components of the translational machinery and the upstream signalling pathways that modulate them have provided important new insights into the mechanisms by which hormones, growth factors, nutrients and cellular energy status control protein synthesis in mammalian cells. The importance of proper control of mRNA translation is strikingly illustrated by the fact that defects in this process or its control are implicated in a number of disease states, such as cancer, tissue hypertrophy and neurodegeneration. Signalling pathways such as those involving mTOR (mammalian target of rapamycin) and mitogen-activated protein kinases modulate the phosphorylation of translation factors, the activities of the protein kinases that act upon them and the association of RNA-binding proteins with specific mRNAs. These effects contribute both to the overall control of protein synthesis (which is linked to cell growth) and to the modulation of the translation or stability of specific mRNAs. However, important questions remain about both the contributions of individual regulatory events to the control of general protein synthesis and the mechanisms by which the translation of specific mRNAs is controlled.
Article
Full-text available
Physical exercise is a modality of non-pharmacological treatment for sleep disorders. Contradicting results are still found in studies of the effect of exercise on sleep. Among the substances that have been described as sleep modulators, cytokines produced during the recovery period after an acute exercise session are very important. Various studies have verified that physical exercise may alter the plasma concentration of the many pro-inflammatory cytokines that may in turn modulate sleep. A number of factors seem to mediate this effect of exercise, including duration, intensity, and form of exercise, in addition to temperature and metabolic alterations. The mechanisms through which exercise promotes alterations in sleep architecture remain to be clarified. Researchers speculate that many hormones and substances produced by metabolism may affect sleep. Therefore, the object of this review is to discuss the effects of exercise and cytokines on sleep, and the relation between these two sleep-regulating components, raising the hypothesis that the alterations in sleep promoted by exercise are mediated by cytokines, which, by increasing the nREM sleep phase, would stimulate the regenerating characteristics of sleep.
Article
Full-text available
The present study was designed to test the hypothesis that increasing physical activity by running exercise could favor the recovery of muscle mass after extensive injury and to determine the main molecular mechanisms involved. Left soleus muscles of female Wistar rats were degenerated by notexin injection before animals were assigned to either a sedentary group or an exercised group. Both regenerating and contralateral intact muscles from active and sedentary rats were removed 5, 7, 14, 21, 28 and 42 days after injury (n = 8 rats/group). Increasing contractile activity through running exercise during muscle regeneration ensured the full recovery of muscle mass and muscle cross-sectional area as soon as 21 days after injury, whereas muscle weight remained lower even 42 days postinjury in sedentary rats. Proliferator cell nuclear antigen and MyoD protein expression went on longer in active rats than in sedentary rats. Myogenin protein expression was higher in active animals than in sedentary animals 21 days postinjury. The Akt-mammalian target of rapamycin (mTOR) pathway was activated early during the regeneration process, with further increases of mTOR phosphorylation and its downstream effectors, eukaryotic initiation factor-4E-binding protein-1 and p70(s6k), in active rats compared with sedentary rats (days 7-14). The exercise-induced increase in mTOR phosphorylation, independently of Akt, was associated with decreased levels of phosphorylated AMP-activated protein kinase. Taken together, these results provided evidence that increasing contractile activity during muscle regeneration ensured early and full recovery of muscle mass and suggested that these beneficial effects may be due to a longer proliferative step of myogenic cells and activation of mTOR signaling, independently of Akt, during the maturation step of muscle regeneration.
Article
The catabolic properties of glucocorticoid hormones are largely attributable to dual regulation of protein degradation and synthesis. With regard to the latter, glucocorticoids modulate the translational machinery, namely that component functional in translation initiation. This investigation revealed that in L6 myoblasts, dexamethasone, a synthetic glucocorticoid, deactivated the ribosomal protein S6 kinase (p70S6k) within 4 h, as evidenced by diminished phosphorylation of its physiological substrate, the 40S ribosomal protein S6. This deactivation correlated with dephosphorylation of p70S6k at Thr389, whereas phosphorylation of Ser411 was unaffected. Furthermore, glucocorticoid administration induced dephosphorylation of the cap-dependent translational repressor, eukaryotic initiation factor 4E (eIF4E) binding protein 1 (4E-BP1), thereby facilitating conjunction of the inhibitor and eIF4E. The mechanism of action is reminiscent of classical transcriptional regulation by steroid hormone receptors in that these effects were preceded by a temporal lag and were sensitive to inhibitors of glucocorticoid receptor function as well as transcriptional and translational inhibition. Okadaic acid and calyculin A corrected the dexamethasone-induced dephosphorylation of p70S6k and 4E-BP1, implicating a PP1- and/or PP2A-like protein phosphatase(s) in the observed phenomena. Hence, glucocorticoids attenuate distal constituents of the phosphatidylinositol-3 kinase signaling pathway and thereby encumber the protein synthetic apparatus.
Article
Leptin levels were stable across the daytime period under both sleep conditions, which was consistent with the fact that calories were exclusively delivered in the form of a constant glucose infusion. Average total sleep time was 9 hours and 8 minutes when the men spent 10 hours in bed and 3 hours and 53 minutes when the men spent 4 hours in bed (P < 0.01). When spending 4 hours in bed, the participants had mean leptin levels that were 18% lower (2.1 ng/mL vs. 2.6 ng/mL; P = 0.04) (Figure 1, part A) and mean ghrelin levels that were 28% higher (3.3 ng/mL vs. 2.6 ng/mL; P = 0.04) (Figure 1, part B) than when the participants spent 10 hours in bed. The ratio of the concentrations of orexigenic ghrelin to anorexigenic leptin increased by 71% (CI, 7% to 135%) with 4 hours in bed compared with 10 hours in bed. Sleep restriction relative to sleep extension was associated with a 24% increase in hunger ratings on the 10-cm visual analogue scale (P < 0.01) and a 23% increase in appetite ratings for all food categories combined (P = 0.01) (Figure 1, parts C and D, and Table 1). The increase in appetite tended to be greatest for calorie-dense foods with high carbohydrate content (sweets, salty foods, and starchy foods: increase, 33% to 45%; P = 0.06) (Table 1). The increase in appetite for fruits and vegetables was less consistent and of lesser magnitude (increase, 17% to 21%) (Table 1). Appetite for protein-rich nutrients (meat, poultry, fish, eggs, and dairy foods) was not significantly affected by sleep duration (Table 1). When we considered the changes in ghrelin and leptin in an integrated fashion by calculating the ghrelin-to-leptin ratio, the increase in hunger was proportional to the increase in ghrelin-to-leptin ratio (r = 0.87) (Figure 2). Almost 70% of the variance in increased hunger could be accounted for by the increase in the ghrelin-to-leptin ratio.
Article
Several pieces of evidence support that sleep duration plays a role in body weight control. Nevertheless, it has been assumed that, after the identification of orexins (hypocretins), the molecular basis of the interaction between sleep and energy homeostasis has been provided. However, no study has verified the relationship between neuropeptide Y (NPY) and orexin changes during hyperphagia induced by sleep deprivation. In the current study we aimed to establish the time course of changes in metabolite, endocrine, and hypothalamic neuropeptide expression of Wistar rats sleep deprived by the platform method for a distinct period (from 24 to 96 h) or sleep restricted for 21 days (SR-21d). Despite changes in the stress hormones, we found no changes in food intake and body weight in the SR-21d group. However, sleep-deprived rats had a 25-35% increase in their food intake from 72 h accompanied by slight weight loss. Such changes were associated with increased hypothalamus mRNA levels of prepro-orexin (PPO) at 24 h followed by NPY at 48 h of sleep deprivation. Conversely, sleep recovery reduced the expression of both PPO and NPY, which rapidly brought the animals to a hypophagic condition. Our data also support that sleep deprivation rapidly increases energy expenditure and therefore leads to a negative energy balance and a reduction in liver glycogen and serum triacylglycerol levels despite the hyperphagia. Interestingly, such changes were associated with increased serum levels of glucagon, corticosterone, and norepinephrine, but no effects on leptin, insulin, or ghrelin were observed. In conclusion, orexin activation accounts for the myriad changes induced by sleep deprivation, especially the hyperphagia induced under stress and a negative energy balance.
Article
Poor sleep has increasingly gained attention as a potential contributor to the recent obesity epidemic. The increased prevalence of obesity in Western nations over the past half-century has been paralleled by a severe reduction in sleep duration. Physiological studies suggest reduced sleep may impact hormonal regulation of appetite. Prospective studies suggest reduced habitual sleep duration as assessed by self-report is an independent risk factor for an increased rate of weight gain and incident obesity. Cross-sectional studies have demonstrated that the association between reduced sleep and obesity persists when sleep habits are measured objectively, that the association is as a result of elevations in fat and not muscle mass and that this association is not related to sleep apnoea. Thus, reduced sleep appears to represent a novel, independent risk factor for increased weight gain. Further research is needed to determine whether interventions aimed at increasing sleep may be useful in combating obesity.
Article
The effects of growth-suppressing and muscle-wasting treatments on muscle protein turnover and amino acid concentrations were determined in vivo. All treatments depressed protein synthesis and some treatments depressed protein breakdown. Only prolonged starvation increased protein breakdown. Muscle protein mass is regulated primarily through alterations in protein synthesis in all except emergency conditions. The increased concentrations of the branched-chain amino acids indicate that they are unlikely to be involved in this regulation.
Article
Previous studies have reported that prolonged administration of pharmacological doses of glucocorticoids in young rats results in a rise in urinary 3-methyl-L-histidine (3-MH) excretion followed by a fall to initial levels by 8 days. To determine whether this response reflects events in skeletal muscle, protein breakdown in this tissue was evaluated using the perfused hindquarter preparation with rats treated with corticosterone (10 mg X 100 g-1 X day-1) for 2, 4, or 8 days. Myofibrillar and total cell proteolysis were evaluated by measuring the release of 3-MH and tyrosine, respectively, after inhibition of protein synthesis with cycloheximide. Corticosterone treatment resulted in an early increase (1-4 days) followed by a fall (4-8 days) in 3-MH excretion. 3-MH release by the perfused hindquarter of treated rats responded in a similar manner, in that its release increased at days 2 and 4 and decreased to control levels by day 8. On the other hand, corticosterone treatment did not affect the release of tyrosine by the perfused hindquarter. Corticosterone treatment diminished protein synthesis in muscle by 30-50% (P less than 0.01), which unlike 3-MH release by perfused muscle persisted throughout the treatment period. The data indicate that glucocorticoids specifically augment the breakdown of myofibrillar proteins in skeletal muscle. This response is attenuated with prolonged treatment and is unrelated to a loss of metabolic effectiveness of the steroid. Also our findings suggest that the breakdown of myofibrillar and nonmyofibrillar proteins might be regulated independently.
Article
In order to test the hypothesis that cortisol secretion is inhibited during sleep, six healthy young men (ages 18-24) were studied in a 4-day protocol. A baseline nocturnal sleep period was followed by one night's total sleep deprivation, then sleep at 180 degrees phase shift, and then return to a normal nocturnal sleep episode (SP-3). Plasma cortisol concentrations were measured every 20 min (obtained by an indwelling venous catheter), rectal temperature was measured every minute, and sleep was polygraphically defined. During the first 4 h of sustained sleep, cortisol secretion was decreased even when sleep occurred during a time when the subject was usually awake; conversely, it was elevated if awake at the usual daily time of sleeping. This was not the case for the last 4 h of sleep. Body temperature was also decreased but during each entire 7- to 8-h sleep period. Meals produced only a small brief rise of cortisol and produced no change in body temperature. Stage 4 sleep was increased during the 180 degrees inverted sleep episode and decreased during SP-3, REM sleep however was increased during SP-3. A reciprocal relationship was found between REM and stages 3 and 4 for the second, third, and fourth, and sixth h of sleep for SP-3. These results demonstrate the inhibitory effect of the behavioral complex of sleeping on cortisol secretion superimposed on its endogenous circadian and ultradian rhythm. These neurophysiological events may be used to entrain and time the period and phase of biological rhythms in relation to shift work, sleep deprivation, and transmeridian jet travel.
Article
To determine whether cortisol secretion interacts with daytime sleep in a similar manner to that reported for night sleep, 14 healthy young men were studied during two 24-hour cycles. During one cycle they slept during the night, during the other the sleep period was delayed by 8 hours. Secretory rates were calculated by a deconvolution procedure from plasma cortisol, measured at 10-minute intervals. The amount of cortisol secreted during night sleep was lower than during the corresponding period of sleep deprivation (12.7 +/- 1.1 vs. 16.3 +/- 1.6 mg; p < 0.05), but daytime sleep beginning at the habitual time of morning awakening failed to inhibit cortisol secretion significantly. There was no difference between the amount of cortisol secreted from 0700 to 1500 hours in sleeping subjects and in subjects who were awake during the same period of time (24.2 +/- 1.5 vs. 22.5 +/- 1.4 mg). Even if the comparison between sleeping and waking subjects was restricted to the period 070