Glycaemic Effects of a 156-km Ultra-trail Race in Athletes: An Observational Field Study.

BACKGROUND: Ultra-trail running races pose appreciable physiological challenges, particularly for glucose metabolism. Previous studies that yielded divergent results only measured glycaemia at isolated times. OBJECTIVES: We aimed to explore the impact of an ultra-endurance race on continuously measured glycaemia and to understand potential physiological mechanisms, as well as the consequences for performance and behavioural alertness. METHODS: Fifty-five athletes (78% men, 43.7 ± 9.6 years) ran a 156-km ultra-trail race (six 26-km laps, total elevation 6000 m). Participants wore a masked continuous glucose monitoring sensor from the day before the race until 10 days post-race. Blood was taken at rest, during refuelling stops after each lap, and after 24-h recovery. Running intensity (% heart rate reserve), performance (lap times), psychological stress, and behavioural alertness were explored. Linear mixed models and logistic regressions were carried out. RESULTS: No higher risk of hypo- or hyperglycaemia was observed during the exercise phases of the race (i.e. excluding stops for scientific measurements and refuelling) compared with resting values. Laps comprising a greater proportion of time spent at maximal aerobic intensity were nevertheless associated with more time > 180 mg/dL (P = 0.021). A major risk of hyperglycaemia appeared during the 48-h post-race period compared with pre-race (P < 0.05), with 31.9% of the participants spending time with values > 180 mg/dL during recovery versus 5.5% during resting. Changes in circulating insulin, cortisol, and free fatty acids followed profiles comparable with those usually observed during traditional aerobic exercise. However, creatine phosphokinase, and to a lesser extent lactate dehydrogenase, increased exponentially during the race (P < 0.001) and remained high at 24-h post-race (P < 0.001; respectively 43.6 and 1.8 times higher vs. resting). Glycaemic metrics did not influence physical performance or behavioural alertness. CONCLUSION: Ultra-endurance athletes were exposed to hyperglycaemia during the 48-h post-race period, possibly linked to muscle damage and inflammation. Strategies to mitigate muscle damage or subsequent inflammation before or after ultra-trail races could limit recovery hyperglycaemia and hence its related adverse health consequences. TRIAL REGISTRATION NUMBER: NCT05538442 2022-09-21 retrospectively registered.

Health-related behavioral changes during the COVID-19 pandemic. A comparison between cohorts of French and Italian university students.

This cross-sectional observational study compares the health behaviors of university students in France and Italy, examining how their choices and lifestyles were affected by the COVID-19 pandemic with the aim of contributing to the development of adequate public health and higher education institutions interventions. The French cohort was investigated between January and February 2022, while the Italian cohort was examined between March and April 2022. In both contexts, data were collected through web surveys using institutional directories of university degree programs. Data were collected using standardized tools, validated and recovered in full or partial form. The tool used consisted of three specific sections (general experience, eating habits, physical activity), to which a fourth, dedicated to describing the sociographic picture of the respondents, was added. It was found that the pandemic mainly affected the mental health and sense of well-being of young people in both countries. The pandemic altered dietary habits (41.8% of the French subjects and 38.3% of the Italians declared an increasing of their food intake), alcohol consumption (9.0% of the Italian respondents and 4.0% of the French respondents reported an increased alcohol consumption), propensity to smoke (among the French 85.3% subjects remained non-smokers versus 65.3% of the Italian subjects), sleep quality (25.7% of Italian students 16.6% of French students experienced a decline in the quality of their sleep), and physical activity levels (the percentage of physically active French subjects rose to 72.4%, whereas among Italian students, it dropped to 68,4%). The results emphasize the need for the implementation of relational and psychological interventions, even digital, to face the consequences of social isolation and negative changes in everyday behaviors due to the restrictions during the COVID-19 pandemic.

Effect of Aerobic Exercise Training on Sleep and Core Temperature in Middle-Aged Women with Chronic Insomnia: A Randomized Controlled Trial.

BACKGROUND: Exercise represents a viable non-pharmacological intervention to help treating insomnia but the interaction mechanisms between sleep and physical activity still remain poorly understood. The aim of this study was to investigate the effect of a aerobic exercise training intervention on sleep and core temperature. METHODS: Twenty-four adult women suffering from insomnia participated in this study. They were randomized into an exercise group and a control group. Aerobic exercise training consisted in moderate to vigorous aerobic exercise training for 12 weeks. Outcome measures included both subjective (Insomnia Severity Index, ISI) and objective (actigraphy recordings) sleep quality assessments, and core body temperature continuously recorded for a minimum 24 h. RESULTS: The exercise group showed a decrease in ISI (p < 0.001) and in various objective sleep parameters. The core temperature batyphase value was lowered (p = 0.037) whereas its amplitude was larger (p = 0.002). We also found a tight correlation between the evolution of insomnia and the evolution of mean night-time core temperature and batyphase values. CONCLUSIONS: A moderate to vigorous aerobic exercise program appears to be an effective non-drug therapy for improving sleep in women with insomnia. In addition, exercise programs should aim to increase core body temperature during practice to induce sleep-promoting adaptations and rebound.

Study of the Kinetics of the Determinants of Performance During a Mountain Ultramarathon: Multidisciplinary Protocol of the First Trail Scientifique de Clécy 2021.

BACKGROUND: The growing interest of the scientific community in trail running has highlighted the acute effects of practice at the time of these races on isolated aspects of physiological and structural systems; biological, physiological, cognitive, and muscular functions; and the psychological state of athletes. However, no integrative study has been conducted under these conditions with so many participants and monitoring of pre-, per-, and postrace variables for up to 10 days over a distance close to 100 miles. OBJECTIVE: The aim of this study was to evaluate the kinetics of the performance parameters during a 156 km trail run and 6000 m of elevation gain in pre-, per-, and postrace conditions. The general hypothesis is based on significant alterations in the psychological, physiological, mechanical, biological, and cognitive parameters. METHODS: The Trail Scientifique de Clécy took place on November 11, 2021. This prospective experimental study provides a comprehensive exploration of the constraints and adaptations of psychophysiological and sociological variables assessed in real race conditions during a trail running of 156 km on hilly ground and 6000 m of elevation gain (D+). The study protocol allowed for repeatability of study measurements under the same experimental conditions during the race, with the race being divided into 6 identical loops of 26 km and 1000 m D+. Measurements were conducted the day before and the morning of the race, at the end of each lap, after a pit stop, and up to 10 days after the race. A total of 55 participants were included, 43 (78%) men and 12 (22%) women, who were experienced in ultra-trail-running events and with no contraindications to the practice of this sport. RESULTS: The launch of the study was authorized on October 26, 2021, under the trial number 21-0166 after a favorable opinion from the Comité de Protection des Personnes Ouest III (21.09.61/SIRIPH 2G 21.01586.000009). Of the 55 runners enrolled, 41 (75%) completed the race and 14 (25%) dropped out for various reasons, including gastric problems, hypothermia, fatigue, and musculoskeletal injuries. All the measurements for each team were completed in full. The race times (ie, excluding the measurements) ranged from 17.8206 hours for the first runner to 35.9225 hours for the last runner. The average time to complete all measurements for each lap was 64 (SD 3) minutes. CONCLUSIONS: The Trail Scientifique de Clécy, by its protocol, allowed for a multidisciplinary approach to the discipline. This approach will allow for the explanation of the studied parameters in relation to each other and observation of the systems of dependence and independence. The initial results are expected in June 2022. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR1-10.2196/38027.

Neuroenhancement in French and Romanian University Students, Motivations and Associated Factors.

This cross-sectional study aimed to determine the use of neuroenhancers, the motivations and factors associated with their use in French and Romanian university students. Students from two universities in France (Rouen and Opal Coast University) and one in Romania (Cluj-Napoca) were asked to complete a self-administered anonymous questionnaire, either online or on paper, about the use of three different categories of substance: Prescription drugs (methylphenidate, modafinil, and beta-blockers), drugs of abuse (alcohol, cannabis, cocaine, and amphetamines), and soft enhancers (coffee, vitamins, caffeine tablets, and energy drinks). In total, 1110 students were included: The users were 2.2% for prescription drugs, 4.3% for drugs of abuse, and 55.0% for soft enhancers. Students used neuroenhancement to stay awake for study (69.3%), to improve concentration (55.5%), to decrease stress (40.9%), and to improve memory (39.6%). Neuroenhancement was considered to meet expectations by 74.4% of users. The factors associated with the use of drugs of abuse were frequent binge drinking (Adjusted Odds Ratio-AOR: 6.49 [95% CI: 2.53-16.6]), smoking (AOR: 5.50 [95% CI: 2.98-10.14]), having a student job (AOR: 2.42 [95% CI 1.13-5.17]), and being male (AOR: 2.23 [95% CI:1.21-4.11]). No significant associations with eating disorders were detected for any of the three categories of substances. University students reported neuroenhancement with prescription drugs, drugs of abuse, and mainly soft enhancers. These substances were used mainly to increase the waking hours. Educational programs in universities seem to be required in order to increase student awareness of the problems caused by neuroenhancements, and to decrease the associated risks by changing students' attitudes and beliefs.

Estimated physical fitness and sociability: an interdisciplinary pilot study among French students.

BACKGROUND: The aim of this pilot study is to explore the main social factors influencing estimated physical fitness. METHODS: During the academic year of 2014/2015, 909 students from two French universities of the Hauts-de-France region completed a study including standardized anonymous self-reported questionnaires. Data were related to age, sex, social class, physical activity, social life and sociability. Physical fitness estimation was assessed through a validated VO2max questionnaire. RESULTS: A total of 749 17- to 24-year-old students were included. The mean age was 19.58. The sample was composed mainly of girls (59.68%). The mean estimated VO2max was 39.30±2.29 for males and 32.79±2.56 for girls. Some significant dependence and risk factors were found between estimated PF and some sociocultural aspects. CONCLUSIONS: Our study shows the importance of the socialization environment. The role, the age and the employment status of the parents are significant as they are a reference for the practice of sports and physical activities. The level of independence and sociability is strongly correlated to estimated physical fitness. These findings stress the need to develop a more holistic study, based on comprehensive and interdisciplinary approaches.

Photoperiod Impact on a Sailor's Sleep-Wake Rhythm and Core Body Temperature in Polar Environment.

INTRODUCTION: Studies have reported circadian desynchronizations and sleep disruptions in onshore populations in the Arctic during the polar day. Although the Arctic region is becoming more accessible by sea and evidence is growing to implicate the importance of fatigue in sailing accidents, no study related to circadian disruptions has focused on sailors. The aim of this study was to observe, during a 155-d polar sailing trip between Greenland and Russia, the evolution of the sleep-wake rhythm and core body temperature (Tc) in a sailor. METHODS: During the expedition, an electronic sleep diary was recorded daily and a continuous measurement of Tc using telemetric pills was performed every 10 d (recording depending on transit time, ≈24 h). Ephemerides were manually determined day by day using global positioning system position and revealed 3 phases (phase 1: decrease of night duration; phase 2: polar day; phase 3: increase of night duration). RESULTS: A significant difference (P<0.05) was observed in daily sleep time between phase 2 (7.6±2.5 h) and phase 3 (8±2 h). The period of Tc rhythm changed during the expedition (phase 1: 24.2±0.5 h; phase 2: 25±0.3 h; phase 3: 24±0.6 h). Dissociation between Tc rhythm and sleep occurred during phase 2. CONCLUSIONS: Our study observed that during a polar sailing expedition, many circadian disruptions appeared as free-running rhythms or dissociation between sleep and Tc rhythm. Future studies will evaluate effects of these disruptions and their probable association with accident risks.

Cognitive performance and self-reported sleepiness are modulated by time-of-day during a mountain ultramarathon.

Ninety-two runners completed the study during a 168 km mountain ultramarathon (MUM). Sleepiness, self-reported sleep duration, and cognitive performance were assessed the day before the race and up to eight checkpoints during the race. Sleepiness was assessed using the Karolinska Sleepiness Scale. Cognitive performance was also assessed using the Digital Symbol Substitution Task (DSST). Runner reported 23.40 ± 22.20 minutes of sleep (mean ± SD) during the race (race time: 29.38 to 46.20 hours). Sleepiness and cognitive performance decrements increased across this race, and this was modulated by time-of-day with higher sleepiness and greater performance decrements occurring during the early morning hours. Runners who slept on the course prior to testing had poorer cognitive performance, which may suggest that naps on the course were taken due to extreme exertion. This study provides evidence that cognitive performance deficits and sleepiness in MUM are sensitive to time into race and time-of-day.

Effects of a 12-week physical activities programme on sleep in female university students.

Lack of sleep is known to negatively affect adolescent's health and the links between regular physical activity and sleep are unclear.This pilot study investigated whether the regular practice of physical activities among sedentary female students would improve their sleep. Nineteen female students, identified as sedentary and having poor subjective sleep quality were assigned in two groups to a 12-week university physical activities programme in accordance with the recommendations of World Health Organisation (N = 10) or to a control condition (N = 9). Sleep was assessed with actigraphy before and after the study and with the Pittsburg Sleep Quality 15 Index (PSQI) at the beginning, middle, and end of the study. The intensity of physical activities was controlled by heart rate monitor. The analysis showed that sleep quality in the physical activities group improved, with the mean ± SD PSQI score decreasing from 9.1 ± 1.7 to 4.8 ± 2.0. Despite some limitations, these pilot data indicate that a physical activities programme is feasible to implement in students, and that participation in such a programme improves sleep in 18- 24 -year-old female adolescents. Further potential benefits remain to be investigated in follow-up research.

[Physical activity of students: prevalence and profiles of associated risk behaviours]. / Activité physique chez les étudiants : prévalence et profils de comportements à risque associés.

More than 40% of students do not practice any PA. These results highlight the need for a better understanding to develop intervention strategies for students, based on new public health approaches. The contribution of social and physical environmental factors to changes in PA needs to be further explored. .

Sleep Management Strategy and Performance in an Extreme Mountain Ultra-marathon.

We intended to assess the relationship between sleep strategies and performance during the North-Face Ultra-Trail du Mont-Blanc 2013, to test the hypothesis that sleep management can influence athletic performance. Almost all runners specifically adopted sleep management strategies before the race. Among the finishers 72% didn't sleep at all during the race and 28% took a least one break for sleep. Non-sleepers completed the race faster than the sleepers (P = 0.0008). Race time was positively correlated with drowsiness (P < 0.0001) and negatively correlated with the number participations in this race (P = 0.0039). Runners who adopted a sleep management strategy based on increased sleep time before the race completed the race faster (P = 0.0258). Most finishers seemed to be aware of the importance of developing sleep management strategies and increasing sleep time some nights before the race appeared to be the most relevant strategy to improve performance.

Combined effects of sleep deprivation and strenuous exercise on cognitive performances during The North Face® Ultra Trail du Mont Blanc® (UTMB®).

This study investigated the effects of combined sleep deprivation and strenuous exercise on cognitive and neurobehavioral performance among long-distance runners completing one of the most difficult ultramarathons in the world. Seventeen runners participated. Each had a wrist-worn actigraph throughout the race to record their sleep time. In addition, each individual's performance in 10-min response-time tests before and after the race was recorded and a questionnaire enabled participants to report any difficulties they experienced during the competition. During race completion times of 27 to 44 h, combined acute lack of sleep (12 ± 17 min of rest during the race) and strenuous exercise (168.0 km) had marked adverse effects on cognitive performances ranging from mere lengthening of response time to serious symptoms such as visual hallucinations. This study suggests that regardless of rest duration and time in race, cognitive performances of ultramarathoners are adversely affected.

Sleep restriction and degraded reaction-time performance in Figaro solo sailing races.

In solo offshore sailing races like those of the Solitaire du Figaro, sleep must be obtained in multiple short bouts to maintain competitive performance and safety. Little is known about the amount of sleep restriction experienced at sea and the effects that fatigue from sleep loss have on sailors' performance. Therefore, we assessed sleep in sailors of yachts in the Figaro 2 Beneteau class during races and compared response times on a serial simple reaction-time test before and after races. Twelve men (professional sailors) recorded their sleep and measured their response times during one of the three single-handed races of 150, 300 and 350 nautical miles (nominally 24-50 h in duration). Total estimated sleep duration at sea indicated considerable sleep insufficiency. Response times were slower after races than before. The results suggest that professional sailors incur severe sleep loss and demonstrate marked performance impairment when competing in one- to two-day solo sailing races. Competitive performance could be improved by actively managing sleep during solo offshore sailing races.

Validation of the Vivago Wrist-Worn accelerometer in the assessment of physical activity.

BACKGROUND: Most accelerometers are worn around the waist (hip or lower back) to assess habitual physical activity. Wrist-worn accelerometers may be an alternative to the waist-worn monitors and may improve compliance in studies with prolonged wear. The aim of this study was to validate the Vivago® Wrist-Worn Accelerometer at various intensities of physical activity (PA) in adults. METHODS: Twenty-one healthy adults aged 20-34 years were recruited for the study. Accelerometer data and oxygen uptake (VO2) were measured at sedentary, light, moderate and vigorous levels of PA. RESULTS: Activity categories and accelerometer counts were: sedentary, 0-15 counts·min-1; light, 16-40 counts·min-1; moderate, 41-85 counts·min-1; and vigorous activity, >; 85 counts·min-1. ANOVA repeated measures was used to determine the relationship between accelerometry data output and oxygen consumption (r = .89; p <; .001). The Bland and Altman method showed good agreement in the assessment of energy expenditure between the indirect calorimetry and the data obtained by the accelerometer. CONCLUSIONS: Results of the study suggest that the Vivago® wrist-worn accelerometer is a valid measure of PA at varying levels of intensity. The study has also defined threshold values at 4 intensities and hence te Vivago® accelerometer may be used to quantify PA in free living conditions among adults. This device has possible application in treating a variety of important health concerns.

The CEMHaVi program: control, evaluation, and modification of lifestyles in obese youth.

PURPOSE: Obesity in children has increased in recent years. Many studies with differing methodologies have been undertaken to treat obesity. The Control, Evaluation, and Modification of Lifestyles in Obese Youth (CEMHaVi) program is a unique 2-year health-wellness program of physical activity and health education for obese youth. Findings of this study represent results at 1-year follow-up. The purpose of this study was to evaluate the effects of the CEMHaVi program. METHODS: Physician-referred subjects (N = 26) participated in the study, 14 girls (13.4 +/- 2.9 years) and 12 boys (12.3 +/- 2.8 years). Measurements included height, weight, body mass index (BMI), academic performance, sleep habits, and health knowledge. The intervention consisted of a unique program of physical activity, including a variety of games specifically selected to be enjoyable, maintain interest, and motivate subjects to adhere. Activity sessions were offered once per week, 2 hours each session, for 12 months. A health education program was offered once every 3 months for 2 hours per session. Health knowledge, academic performance, self-esteem, and sleep were assessed before and after the intervention. Means were calculated at baseline and following intervention and were compared by paired t tests. RESULTS: Findings suggest significant improvements in academic performance (P < .001), quality and quantity of sleep (P < .05), and obesity (P < .05). CONCLUSIONS: The program reduced BMI and improved health knowledge, sleep, and academic performance in obese children. The feasibility of a beneficial lifestyle intervention program is encouraging in addressing obesity and related issues in young boys and girls.