Study of the mechanisms by which carbohydrate administration during prolonged muscle contractions increases performance = Étude des mécanismes par lesquels l'administration de glucides améliore la performance durant des contractions prolongées du muscle

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal

Physical Activity and Mindfulness are Associated with Lower Anxiety in Different but Complementary Ways

International Journal of Exercise Science 15(7): 1075-1084, 2022. Introduction: Anxiety is the most prevalent mental illness worldwide. Physical activity and mindfulness both reduce anxiety. The two are highly related; however, the relative association of physical activity and mindfulness on anxiety has yet to be examined. The present study aimed to evaluate the unique variance accounted for by physical activity and mindfulness on anxiety. Methods: Fifty young adults from a student population (M ± SD = 19 ± 0.2 years old; 58% female) reported their physical activity, mindfulness, and anxiety symptoms at the start of the study and reported their change in state anxiety to an acute psychological stress test, Trier Social Stress Test. Results: Mindfulness explained more of the variance associated with anxiety symptoms at baseline, whereas physical activity explained more of the variance associated with change in state anxiety in response to the acute stressor. Females had higher rates of anxiety symptoms than males suggesting that females may benefit more from mindfulness. In contrast, both males and females reacted similarly to an acute stressor suggesting that both genders may benefit from physical activity. Conclusions: Our findings suggest that physical activity and trait mindfulness may have related, but distinct impacts on anxiety levels. These results have important implications for using these lifestyle interventions to support mental health and point to personalizing interventions to help ease the burden of anxiety felt by the individual

Predictors of Academic Performance in High School Students: The Longitudinal ASAP Study

International Journal of Exercise Science 15(4): 616-631, 2022. Academic performance is influenced by multitude factors. However, little is known about their relative importance and how they evolve over time. The purpose of the present study was to determine the relative importance of cognitive control, physical, psychological and sociological factors as well as lifestyle habits in predicting academic performance in high school students using cross sectional and longitudinal approaches. One hundred and eighty-five grade seventh to ninth students (mean age: 13.1 ± 1.0 years old) from a single high school completed a 3-year prospective study. Academic performance, cognitive control, physical, psychological and sociological factors as well as lifestyle habits were assessed every year during the 3-year study. Results showed that different combinations of factors were found to predict academic performance measures in both male and female students at baseline and after a 3-year period. For example, in female students, screen time and VO2 max were found to be important predictors of academic performance, whereas working memory was the only recurring factor in predicting academic performance in male students. Moreover, our models were able to explain between 6.1 to 52.2% of the variation in the change of the different measures of academic performance. Results of the present study show that academic performance may be predicted by a wide range of multiple factors in high school students. Indeed, the factors that predicted academic performance varied between school subjects, sex and study design, highlighting the complexity of predicting academic performance in high school students

Relationship between academic performance with physical, psychosocial, lifestyle, and sociodemographic factors in female undergraduate students

Background: The purpose of this study was to investigate the relationship between physical, psychosocial, lifestyle and sociodemographic factors with academic performance in female undergraduate students. Methods: One hundred undergraduate female students from the Faculty of Science at the University of Quebec at Montreal participated in this study (mean age = 24.4 ± 4.6 years old). All participants provided their university transcript and had to complete at least 45 course credits from their bachelor degree. Body composition (DXA), handgrip strength, estimated maximal oxygen consumption (VO2max) (Bruce Protocol) and blood pressure were measured. Participants also completed a questionnaire on their psychosocial, academic motivation, lifestyle and sociodemographic profile. Results: Significant correlations were observed between GPA with estimated VO2max (r = 0.32), intrinsic motivation toward knowledge (r = 0.23), intrinsic motivation toward accomplishment (r = 0.27) and external regulation (r = -0.30, P = 0.002). In addition, eating breakfast every morning and being an atheist was positively associated with academic performance (P < 0.05). Finally, a stepwise linear regression analysis showed that external regulation, intrinsic motivation toward accomplishment, VO2max levels and eating a daily breakfast explained 28.5 % of the variation in the GPA in our cohort. Conclusions: Results of the present study indicate that motivational, physical and lifestyle factors appear to be predictors of academic performance in female undergraduate students

Gut Microbiota and Metabolic Health: The Potential Beneficial Effects of a Medium Chain Triglyceride Diet in Obese Individuals

Obesity and associated metabolic complications, such as non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2D), are in constant increase around the world. While most obese patients show several metabolic and biometric abnormalities and comorbidities, a subgroup of patients representing 3% to 57% of obese adults, depending on the diagnosis criteria, remains metabolically healthy. Among many other factors, the gut microbiota is now identified as a determining factor in the pathogenesis of metabolically unhealthy obese (MUHO) individuals and in obesity-related diseases such as endotoxemia, intestinal and systemic inflammation, as well as insulin resistance. Interestingly, recent studies suggest that an optimal healthy-like gut microbiota structure may contribute to the metabolically healthy obese (MHO) phenotype. Here, we describe how dietary medium chain triglycerides (MCT), previously found to promote lipid catabolism, energy expenditure and weight loss, can ameliorate metabolic health via their capacity to improve both intestinal ecosystem and permeability. MCT-enriched diets could therefore be used to manage metabolic diseases through modification of gut microbiota

High Intensity Exercise: Can It Protect You from A Fast Food Diet?

The purpose of this study was to assess the ability of high intensity exercise to counteract the deleterious effects of a fast food diet on the cardiometabolic profile of young healthy men. Fifteen men were subjected to an exclusive fast food diet from a popular fast food restaurant chain (three extra value meals/day + optional snack) for 14 consecutive days. Simultaneously, participants were asked to perform each day high intensity interval training (HIIT) (15 × 60 sec sprint intervals (~90% of maximal heart rate)) on a treadmill. Fast food diet and energy expenditure profiles of the participants during the intervention were assessed as well as body composition (DXA), cardiometabolic profile (lipid, hepatic enzymes, glycated hemoglobin, glucose, insulin, hsC-reactive protein (hsCRP) and blood pressure) and estimated maximal oxygen consumption (VO2 max) pre- and post-experiment. We found significant improvements for fat mass, lean body mass, estimated VO2 max, fasting glucose, serum lipoprotein(a) and hsCRP after the intervention (p &lt; 0.05). HDL-cholesterol significantly decreased (p &lt; 0.002), but the triglycerides/HDL-cholesterol ratio did not change. All other cardiometabolic variables measured remained stable, which includes the primary outcome: the HOMA index (pre: 1.83 ± 1.2 vs. post: 1.54 ± 0.7 values; p = 0.35). In conclusion, in large part, insulin resistance and the cardiometabolic profile of young healthy individuals seems to be protected by HIIT from a fast food diet