SLEEP BEHAVIOUR, ACTIVITY CIRCADIAN RHYTHM AND PSYCHOPHYSIOLOGICAL RESPONSES TO PHYSICAL ACTIVITY: THE CHRONOTYPE EFFECT.

In the past, several studies investigated the circadian rhythm of different physiological variables associated to sport, the time-of-day effects on physical performance and the reciprocal relationship between sleep and physical activity but there is a scarce literature on how the chronotype could influence all these aspects. Therefore, the purposes of this Ph.D. thesis are: 1) to assess, with the use of actigraphy, the relationship between the three chronotypes and the circadian rhythm of activity levels and to determine whether sleep parameters respond differently with respect to the time (weekdays versus the weekend) in M-types, N-types and E-types; 2) to evaluate whether a linear regression formula using the MEQ score would predict the actigraphy-based acrophase in a young Italian population; 3) to investigate the effects of chronotype on psychophysiological responses (RPE, HR and walking time) to a submaximal self-paced walking task performed in two different times of day (08:30-09:00 vs 15:30-16:30). The results showed that: 1) the acrophases of the activity levels were significantly different in M- (14:32h), N- (15:42h) and E-types (16:53h) (p<0.001) while MESOR and amplitude were similar among chronotypes; there was also a significant interaction between the chronotype and sleep parameters: Sleep Efficiency of the E-types was poorer than that of the M- and N-types during weekdays (77.9% \ub1 7.0 versus 84.1% \ub1 4.9 and 84.1% \ub1 5.2) (p=0.005) but was similar to that measured in the M- and N-types during the weekend. 2) There was a significant linear relationship between MEQ and the Acrophase thus, enabling us to use the equation of the regression line to obtain predictions. The predictive equation resulted as follows: 1238.7-5.487*MEQ. The precision of the estimates was excellent and the r2 was 0.70, indicating that 70% of the variance in the acrophase was explained by MEQ. 3) It was found a significant interaction between chronotype and time of day. The post hoc analysis showed a significant difference for RPE in the morning session, with E-types reporting higher RPE compared with the M-types (14.33 \ub1 2.45 vs 12.00 \ub1 1.66) (p<0.01). This Ph.D. thesis highlights two key findings: 1) the chronotype influence the activity circadian rhythm and the sleep parameters suggesting that E-types accumulate a sleep deficit during weekdays, due to social and academic commitments and that they recover from this deficit during \u201cfree days\u201d on the weekend; 2) the chronotype and the time of day when a physical task in undertaken can influence the RPE response

Exploring circannual rhythms and chronotype effect in patients with Obsessive-Compulsive Tic Disorder (OCTD) : a pilot study

Background: The aim of this study was to test, through a chronobiologic approach, the existence of a significant circannual rhythm of tics and obsessive-compulsive symptoms in patients with Obsessive-Compulsive Tic Disorder (OCTD). The chronotype effect on tics and OC symptoms during seasons was also studied. Methods: Patients with a diagnosis of OCTD (N = 37; mean age = 18.78 \ub1 8.61) underwent four clinical evaluations: Winter (WIN), Spring (SPR), Summer (SUM) and Autumn (AUT). Tics were evaluated through Yale Global Tic Severity Scale (YGTSS) and OC symptoms through Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Patients\u2019 chronotype was assessed by the Horne-Ostberg morningness-eveningness questionnaire (MEQ), which categorizes subjects according to the individuals'chronotype, being morning-type, evening-type, and neither-type. Results: A statistically significant circannual rhythm was observed for OC symptoms (p = 0.007), with the acrophase occurring between AUT and WIN. Y-BOCS differed along the year (p = 0.0003 and \u3b72p = 0.40) with lower results in SUM compared to WIN (p &lt; 0.05) and AUT (p &lt; 0.01). Tics displayed no circannual rhythm and YGTSS scores were comparable among seasons. Patients were classified as 15 morning-types (40.5%) 15 neither-types (40.5%) and 7 evening-types (19.0%). YGTSS data were similar for all chronotypes while Y-BOCS results were greater during SUM in evening-types than morning-type patients (p &lt; 0.05; 15.7 \ub1 5.2 vs 3.4 \ub1 6.0). Limitations: It is essential to investigate the existence of tics and OC symptoms circannual rhythms over the course of more than one year with a larger sample. Conclusions: OC symptoms displayed a significant circannual rhythm and were influenced by patients\u2019 chronotype. On the contrary, tics resulted similar among seasons and chronotypes

Heart Rate Variability in Sport Performance : Do Time of Day and Chronotype Play A Role?

A reliable non-invasive method to assess autonomic nervous system activity involves the evaluation of the time course of heart rate variability (HRV). HRV may vary in accordance with the degree and duration of training, and the circadian fluctuation of this variable is crucial for human health since the heart adapts to the needs of different activity levels during sleep phases or in the daytime. In the present review, time-of-day and chronotype effect on HRV in response to acute sessions of physical activity are discussed. Results are sparse and controversial; however, it seems that evening-type subjects have a higher perturbation of the autonomic nervous system (ANS), with slowed vagal reactivation and higher heart rate values in response to morning exercise than morning types. Conversely, both chronotype categories showed similar ANS activity during evening physical tasks, suggesting that this time of day seems to perturb the HRV circadian rhythm to a lesser extent. The control for chronotype and time-of-day effect represents a key strategy for individual training schedules, and, in perspective, for primary injury prevention

Effect of a Habitual Late-Evening Physical Task on Sleep Quality in Neither-Type Soccer Players

Purpose: The aim of this study was to investigate objective and subjective sleep quality, daytime tiredness and sleepiness in response to a late-evening high intensity interval training (HIIT) session in neither-type soccer players that habitually trained late in the day. This is the first study that considered both athletes' chronotype and habitual training time as crucial factors when assessing sleep quality in relation to an evening physical task. Methods: In this longitudinal, prospective, observational study, 14 Italian soccer players were recruited (mean age: 26.1 \ub1 4.5 years; height: 1.81 \ub1 0.06 m; weight: 78.9 \ub1 6.1 kg) and performed an extraroutine 4 x 4-min HIIT session at 09:00 p.m. Players used to train always between 09:00 and 11:00 p.m during the competitive season. All subjects wore an actigraph to evaluate their objective sleep parameters and a sleep diary was used to record subjective values of sleep quality, daytime tiredness, and daytime sleepiness. All data were analyzed as: the mean of the two nights before (PRE), the night after (POST 1), and the mean of the two nights after (POST 2) the extra-routine HIIT session. The subjects' chronotype was assessed by the morningness-eveningness questionnaire (MEQ). Results: All players were classified as N-types (mean MEQ score: 49.4 \ub1 3.7). None of the actigraph parameters nor the subjective values of sleep quality, tiredness, and sleepiness showed significant changes in PRE, POST 1, and POST 2. Conclusion: The results of our study added more information regarding sleep quality outcomes in response to a late-evening HIIT session. Athletic trainers and medical staff should always control for chronotype and habitual training time when assessing variations to sleep quality in athletes

Actigraphy-based sleep behavior and high intensity interval training (HIIT): the chronotype effect

INTRODUCTION Physical activity can improve sleep quality through numerous mechanisms by creating a state of general well-being. It is difficult to understand exactly how exercise impacts on sleep and vice versa: different volumes, intensities and types of physical activity could have some positive or negative effects on sleep and sleep loss or restriction could influence both physical and cognitive performances (Souissi et al., 2008). It is largely demonstrated that M-types go to bed and wake up earlier than E-types and that E-types use to sleep less during the working days but more during the weekends (Vitale et al., 2015). The aim of this study was to evaluate the effects of sleep behavior following the 4x4 min of high-intensity interval training (HIIT) proposed by Helgerud (Helgerud et al., 2001), performed by subjects at 08:00 pm, also taking into account the influence of the chronotype variable. METHODS 15 male subjects (mean age: 20 \ub1 2), soccer players, enrolled in the School of Exercise Science, University of Milan, at baseline filled in the Horne-Ostberg Morningness-Eveningness Questionnaire (MEQ) for the assessment of chronotype (Horne &amp; Ostberg, 1976). An actigraph monitoring was performed for one week to detect nocturnal sleep PRE-HIIT, and POST-HIIT taking into account the following actigraphy-based sleep parameters: Actual Sleep % (AS), Sleep Efficiency % (SE), Immobile Time % (IT) and Movement Fragmentation Index % (MFI). We compared sleep behavior from PRE to POST conditions between chronotypes. RESULTS 9 soccer players resulted E-types while 6 resulted M-types. E-types and M-types did not present any significant differences for sleep behavior from PRE to POST condition, nevertheless M-types showed a trend to worsen their sleep in the POST condition with a decrease in SE and an increase in MFI. DISCUSSION Our results suggest that HIIT performed at 08:00 pm did not affect the sleep behavior in E-types while M-types, who are more active in the first part of the day, showed a strong trend to worse their sleep quality therefore it seems that they are disadvantaged when performing a training task in the evening. REFERENCES \u2022 Helgerud J et al., Aerobic endurance training improves soccer performance, Med Sci Sports Exerc.2001 Nov; 33(11):1925-31 \u2022 Horne JA &amp; Ostberg O, A self-assessment questionnaire to determine morningness-eveningness in human circadian rhythms, International Journal of Chronobiology 1976; 4(2):97-110 \u2022 Souissi N et al., Effect of time of day and partial sleep deprivation on short-term, high-power output, Chronobiol. Int.2008; 25(6):1062-76 \u2022 Vitale JA, et al., Chronotype influences activity circadian rhythm and sleep: differences in sleep quality between weekdays and weekend, Chronobiol. Int.2015 Apr; 32(3):405-1

Circadian rhythm of activity levels: influence of chronotype.

Aim: The aim of this study is to investigate, by an actigraph monitoring, the differences in the circadian rhythm of activity level in relation to the chronotype for the sake of studying its influence on physical performance. Morning-type (M-type), Evening-type (E-types) and Neither-type (N-type) are the classified chronotypes; several studies showed the differences between M-types and E-types in the circadian rhythm of different physiological variables: M-types use to wake up and go to bed early and to have their best performances in the first part of the day, otherwise E-types go to bed and wake up late and they have the peak performances in the evening (Vitale et al., 2013). Method: The morningness\u2013eveningness questionnaire (MEQ) was administered to 502 college students to determine their chronotypes. Fifty subjects (16 M-types, 15 N-types and 19 E-types) were recruited to undergo a 7-days monitoring period with an actigraph (Actiwacth actometers, CNT, Cambridge, UK) to evaluate their sleep parameters and the circadian rhythm of their activity levels. To evaluate the circadian rhythmicity of activity levels we used the single cosinor method (Halberg et al., 1977) and we define three parameters characteristic of each statistically significant rhythm: M, MESOR (Midline Estimating Statistic Of Rhythm); A, Amplitude; \u3d5, acrophase. The population circadian characteristics were determined and then compared using the Hotelling test. Results: Rhythmometric analysis, with the single cosinor method, on the activity data collected by the actigraph revealed a statistically significant circadian rhythm (p<0.001) for all the 50 subjects. The population mean cosinors were calculated grouping the different chronotypes: M-types, E-types and N-types (p<0.001). No statistical differences about MESOR were showed for all group combinations (p>0.05) but a significant difference (p<0.05) was observed if considering the Amplitude-Acrophase test for all groups combinations, in particular M-types had an early acrophase of the circadian rhythm of the activity levels, at 14.37, while E-types showed an acrophase with more than 2 hours late, at 17.04 (p<0.001); the group of Ntypes showed an intermediate acrophase, at 15.45, between morning-types and evening-types. Conclusion: We can assume that there is a clear difference between \u201clarks\u201d and \u201cowls\u201d and this results are in line with other studies that showed the biological differences among chronotypes. We can conclude that M-types are more active in the early afternoon and that E-types have the peak of their activity in the late afternoon. Further studies are needed to better understand if and how the chronotype influence a physical performance. References 1. Halberg F., Carandente F., Cornelissen G., Katinas G.S. (1977). Glossary of chronobiology. Chronobiologia 4 (Suppl. 1):1-189. 2. Vitale J.A., Calogiuri G., Weydahl A. (2013). Percept. Mot. Skills. 116(3):1020-1028

Actigraphy-based activity levels and anthropometric measurements in breast cancer survivors: effects of aerobic physical activity

The research investments for the identification of modifiable factors associated with BC recurrences is increasing. Adiposity and other anthropometric indices have been acknowledged as factors involved in BC recurrences and mortality (1). Physical activity (PA) has the potential to counterbalance all of these risk factors (2). We designed a randomized controlled trial to test the effect of an aerobic PA program on anthropometric indices of adiposity and circadian rhythm activity level, evaluated by actigraphy, in BC women included in a dietary intervention trial for prevention of BC recurrences. 40 BC women, aged 35-70 years, were randomized into an intervention (IG=19) and a control group (CG=21). The IG participated in a 3-month active PA program that included two sessions of one-hour brisk walking per week. At baseline and after 3 months, both IG and CG were evaluated for the following parameters: height, weight, BMI, waist circumferences, % fat mass, % lean mass; energy expenditure and motion level (Total Energy Expenditure-TEE, number of steps, PA level, Metabolic Equivalents-METs) using a SenseWear Pro 3 Armband; and activity level circadian rhythm using the Actigraph Actiwatch. At the end of the 3-month PA program, IG showed a significant reduction in fat mass % while CG improved weight and BMI. The population mean cosinor applied to IG and CG at PRE and POST revealed the presence of a significant circadian rhythm in two groups (

Physical performance in high school students: effect of chronotype

Morningness-Eveningness (M-E) is an individual characteristic, defined as chronotype. People are typically categorized in 3 different chronotypes: Morning, Evening and Neither types (M, E and N-types), which differ in the circadian rhythm of many physiological variables. M-types use to wake up and go to bed early and to have their best performances in the first part of the day, otherwise E-types go to bed and wake up late and they have the peak performances in the evening. The chronotype is influenced by both individual and environmental factors and gradually changes during human development. Many studies have demonstrated a trend beginning with a tendency toward morningness in children that gradually evolves into a shift toward eveningness. Approximately at the age of 20 years, this shift reaches its maximum and starts to decline, leading to a growing tendency toward morningness from midadulthood on. This more pronounced eveningness has been found to negatively affect adolescents’ sleep and daytime functioning; even physical performance of adolescents can vary throughout the day because sleep pressure increases, the input from the circadian timing system is optimal or non-optimal to perform the task or both of them. In this study participated 216 students, 124 males and 92 females, attending the first two high school classes (mean age 14-15 years). For the assessment of chronotype, all students compiled the Morningness-Eveningness Questionaire (MEQ), validated by Horne and Ostberg in 1976. For all subjects we collected anthropometric data (weight, height, BMI). All the subjects were categorized as M (n=22), N (n=165), and E-types (n=29). To assess the relationship between chronotype and physical performance, from the sample we recruited 51 subjects, 22 M-type (14 males and 8 females) and 29 E-types (18 males and 11 females), who carried out three Eurofit tests (SHR, Shuttle Run; SBJ, Standing Broad Jump; Cooper endurance test). Preliminary results, although showing some differences in physical performance between E and M chronotype, have not detected statistically significant differences between the two groups

Anthropometric indices of adiposity and fasting glucose metabolism in breast cancer survivors: effects of aerobic physical activity

Adiposity and hypersinsulinemia are factors involved in cancer mortality including BC (1). Physical activity (PA) has the potential to counterbalance these risk factors. In fact, PA has been shown to produce beneficial effects on adiposity and glucose metabolism (2). We thus designed a randomized controlled trial to test the effect of an aerobic PA program on anthropometric indices of adiposity and fasting glucose metabolism in BC women included in a dietary intervention trial for prevention of BC recurrences. 42 BC women, aged 35-70 years, were randomized into an intervention (IG=19) and control group (CG=23). The IG had to participate in a 3-month active PA program that included two sessions of one-hour brisk walking per week. At baseline and after 3-month, all women were requested to undergo an anthropometric visit and to collect a blood sample for determination of fasting insulin and glucose levels. At the end of the 3-month PA a significant reduction in waist circumference (p&lt;0.05) and percentage fat mass (p&lt;0.01) were observed in IG, but not in CG. In addition, only IG increased significantly their Metabolic Equivalent of Task (METs) (p&lt;0.05). Although fasting glucose and insulin levels don\u2019t show any significant change in either group, it is nevertheless encouraging that the two groups displayed an opposite trend as far as the changes in fasting insulin were concerned: fasting insulin shows a mean reduction (-0.9 \uf06dU//ml) in the IG group and a mean increment in the CG (+0.7 \uf06dU/ml). The results suggest that a standardized PA program in BC survivors reduces anthropometric indices of adiposity and may prove useful in preventing the development of hyperinsulinemic levels. References 1. Mann et al. (2014) Changes in insulin sensitivity in response to different modalities of exercise: a review of the evidence. Diabetes Metab Res Rev. 30(4): 257-268. 2. Pisani (2008) Hyper-insulinaemia and cancer, meta-analyses of epidemiological studies. Arch Physiol Biochem 114(1): 63\u201370