Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme最新文献

Low-volume interval training has been demonstrated to improve indices of 24 h glycemic control using continuous glucose monitoring in individuals with or at risk for metabolic diseases. Nonetheless, there are inconsistencies in the literature with respect to the effects of interval exercise on 24 h glycemia, which may partly result from different nutritional conditions and/or controls adopted across various studies. This current opinion aims to provide a concise overview of the effects of acute and chronic interval exercise on 24 h glycemic control, while also describing how nutrition can influence and modify these responses. Given the distinct impact of dietary intake on blood glucose regulation, the adoption of diverse dietary control strategies during measurement of 24 h glycemia-spanning from using the participant's habitual diet to providing standardized meals customized to individual energy requirements-may contribute to varying conclusions across studies regarding the influence of interval exercise on 24 h glycemia. In addition, nutritional manipulations surrounding exercise, including whether interval exercise commences in the fasted or fed state, the macronutrient composition of post-exercise meals, and the presence of an energy and/or carbohydrate deficit among participants, offer important context when considering the effects of interval exercise on 24 h glycemia. Additional well-controlled studies are warranted to explore the interactive effects of interval exercise and nutrition on 24 h glycemia. These efforts will assist in refining exercise and nutrition recommendations aimed at improving glycemic control.

The aim of this study was to identify eating-related latent profiles based on diet quality and eating behaviours within a population characterized by a body mass index (BMI) of at least 25 kg/m², and to compare metabolic variables between profiles. This analysis was conducted in a sample of 614 adults (45.6% women; 44.8 ± 12.9 years) from the cross-sectional PREDISE study. Participants completed the Three-Factor Eating Questionnaire, the Intuitive Eating Scale-2, the Regulation of Eating Behavior Scale, and three self-administered 24 h food recalls. Waist circumference, blood lipids, blood pressure, and fasting glucose were measured to identify carriers of the metabolic syndrome. A latent profile analysis was performed, and cases of metabolic syndrome were compared between profiles. A three-profile solution was found. Profile 1 (22.8%) was characterized by lower diet quality, lower self-determined motivation for eating, lower restraint, and higher intuitive eating. Profile 2 (44.5%) was characterized by higher diet quality, higher self-determined motivation for eating, higher restraint, lower disinhibition, and higher intuitive eating. Profile 3 (32.7%) was characterized by intermediate diet quality, higher non-self-determined motivation for eating, higher restraint and disinhibition, and lower intuitive eating. We found fewer cases of metabolic syndrome among participants in profile 2 than in the other profiles (p = 0.0001). This study suggests that a profile characterized by a lower disinhibition and higher levels of restraint, intuitive eating, self-determined motivation, and diet quality is associated with a better metabolic health among individuals with a higher BMI.

The purpose of this study was to examine the effects of plant- versus animal-based food intake before exercise on arterial function and subsequent aerobic exercise capacity. Eleven healthy adult males (mean age, 22.6 ± 1.8 years) participated in this study. A plant- or animal-based randomized meal type crossover comparison was conducted on separate days with a uniform protein, fat, and carbohydrate balance. Both carotid-femoral pulse wave velocity (cfPWV), femoral-ankle pulse wave velocity (faPWV), and brachial artery flow-mediated dilatation (FMD) were measured as indexes of aortic and peripheral arterial stiffness and vascular endothelial function, respectively, before and at 120 min after the meal. After these measurements, maximal oxygen uptake was assessed using a graded power test on an electronically braked cycle ergometer. The results revealed that cfPWV was significantly lower, whereas FMD was significantly higher, at 120 min after compared with before the plant-based meal (p = 0.01 and 0.02, respectively). By contrast, cfPWV and FMD did not change at 120 min after compared with before the animal-based meal. In addition, faPWV did not change at 120 min after compared with before the meal for either meal type. Maximal oxygen uptake was higher in the plant- than in the animal-based meal type (p = 0.02). These results suggest that pre-exercise plant-based food intake may improve central arterial stiffness and vascular endothelial function, which may have favorable implications for aerobic exercise capacity.

In recent years, research investigating the dose-response to sprint interval training (SIT) has provided evidence that the number and duration of repetitions in a SIT session can be reduced whilst preserving the beneficial health-related adaptations. Together this research has led to the development of protocols involving minimal doses of SIT: regularly performing just two or three 20-30 s all-out sprints in a 10 min training session has been shown to elicit beneficial metabolic and cardiovascular adaptations. These SIT protocols, which we originally termed "reduced-exertion high-intensity interval training" (or REHIT), have the potential to remove many of the common barriers associated with other SIT protocols, as well as with HIT and aerobic exercise. Here, we critically review the evidence on the efficacy, feasibility and acceptability, and effectiveness of REHIT for improving health and fitness.

Interval walking training (IWT) is a free-living training intervention involving alternating fast and slow walking cycles. IWT is efficacious in improving physical fitness and muscle strength, and reducing factors associated with lifestyle-related diseases. In individuals with type 2 diabetes, IWT improves glycemic control directly through enhanced glucose effectiveness, challenging conventional views on mechanisms behind training-induced improvements in glycemic control. Whereas adherence to IWT in short-term studies is high, ensuring long-term adherence remains a challenge, particularly in populations with chronic diseases and/or overweight/obesity. Long-term studies in real-world settings are imperative to ascertain the widespread effectiveness of IWT and elucidate its impact on hard endpoints.

Using global surface electromyography (sEMG) and the sEMG threshold it has been suggested that children activate their type-II motor unit (MU) to a lesser extent compared with adults. However, when age-related differences in discrete MU activation are examined using sEMG decomposition this phenomenon is not observed. Furthermore, findings from these studies are inconsistent and conflicting. Therefore, the purpose of this study was to examine differences in discrete MU activation of the vastus lateralis (VL) between boys and men during moderate-intensity knee extensions. Seventeen boys and 20 men completed two laboratory sessions. Following a habituation session, maximal voluntary isometric knee extension (MVIC) torque was determined before completing trapezoidal contractions at 70% MVIC. sEMG of the VL was captured and mathematically decomposed into individual MU action potential trains. Motor unit action potential amplitude (MUAPamp), recruitment threshold (RT), and MU firing rates (MUFR) were calculated. We observed that MUAPamp-RT slope was steeper in men compared with boys (p < 0.05) even after accounting for fat thickness and quadriceps muscle depth. The mean MUFR and y-intercept of the MUFR-RT relationship were significantly (p < 0.001) lower in boys than in men. The slope of the MUFR-RT relationship tended to be steeper in men, but the differences did not reach statistical significance (p = 0.056). Overall, our results suggest that neural strategies used to produce torque are different among boys and men. Such differences may be related, in part, to boys' lower MUFR and lesser ability to activate their higher-threshold MUs. Although, other factors (e.g., muscle composition) likely also play a role.

Whether COVID-19-related experienced stress influenced lifestyle habits remains to be thoroughly evaluated among university students. This study examined the relationship between COVID-19-related experienced stress and subsequent lifestyle habits among undergraduate students. This cross-sectional study included 708 undergraduate students from Université Laval (Québec, Canada) participating in the Expériences Pandémiques (ExPan) cohort. Data on COVID-19-related experienced stress and lifestyle were self-reported using a questionnaire completed between February and April of 2022. A stress index (SI) was computed by summing scores associated with 31 situational statements related to the pandemic (e.g., not being able to see friends, dealing with job loss). A healthy lifestyle score (HLS) ranging from zero to seven was calculated based on seven lifestyle habits: moderate-to-vigorous physical activity, sleep quality, fruit and vegetable intake, tobacco and electronic cigarette use, alcohol consumption, cannabis use, and hard or sedative-hypnotic drugs use. In multivariable-adjusted models, a negative association between the SI and the HLS was found (β_{10% increment SI} = -0.23, 95% CI = -0.30, -0.16 HLS point; P < 0.0001). The SI was also negatively associated with sleep quality, and fruit and vegetable consumption, while being positively associated with at-risk alcohol consumption, cannabis use, and hard or sedative-hypnotic drug use. Subgroup analyses suggested a negative relationship between the SI and HLS among participants who did not receive academic accommodations (e.g., additional time for evaluations, personal notetaker), but not those who received such accommodations. This study suggests that COVID-19-related experienced stress was negatively associated with healthy lifestyle habits in this cohort of undergraduate students.

Physical activity and exercise training are especially important for reproductive-aged females as exercise-induced health benefits can also affect their infants. However, levels of physical inactivity remain high among females in this age group, before, during, and after pregnancy. There is a great need for practical and feasible exercise modes to increase adherence to exercise in this population, and interval training may be a time-efficient training modality. Interval training is a form of exercise involving intermittent bouts of intense effort interspersed with recovery periods of rest or lower-intensity exercise. A substantial amount of research indicates that interval training induces superior cardiometabolic health benefits compared with iso-energetic moderate-intensity continuous exercise. This review provides a comprehensive overview of research on interval training interventions in reproductive-aged females across various life stages, focusing on the cardiometabolic health benefits. We discuss the potential role of interval training in premenopausal females with overweight/obesity, polycystic ovary syndrome, and subfertility, as well as the potential influence of oral contraceptives on cardiometabolic adaptations to interval training. Furthermore, this review also highlights recent findings supporting the beneficial role of high-intensity interval training for cardiometabolic health outcomes during pregnancy. In summary, the existing evidence suggests that interval training can improve several cardiometabolic and reproductive outcomes in females spanning different life stages. However, more research is needed to further strengthen the evidence-base for physical activity recommendations for females in their reproductive years of life.

Probiotics are increasingly used to treat conditions associated with gastrointestinal injury and permeability, including exercise-induced gastrointestinal discomfort. This study assessed safety and efficacy of a probiotic in altering the intestinal milieu and mitigating gastrointestinal symptoms (GIS) in endurance runners. In a double blind, crossover study, 16 runners were randomized to 4 weeks of daily supplementation with a probiotic cocktail containing Pediococcus acidilactici bacteria and Lactobacillus plantarum or placebo. Fasting blood and stool samples were collected for measurement of gut permeability markers, immune parameters, and microbiome analyses. Treadmill run tests were performed before and after treatment; participants ran at 65%-70% of VO_2max at 27 °C for a maximum of 90 min or until fatigue/GIS developed. A blood sample was collected after the treadmill run test. In healthy individuals, 4 weeks of probiotic supplementation did not alter health parameters, although a marginal reduction in aspartate aminotransferase levels was observed with probiotic treatment only (p = 0.05). GIS, gut permeability-associated parameters (intestinal fatty acid binding protein, lipopolysaccharide binding protein, zonulin, and cytokines), and intestinal microbial content were not altered by the probiotic supplementation. Post-run measurements of GIS and gut-associated parameters did not differ between groups; however, the observed lack of differences is confounded by an absence of measurable functional outcome as GIS was not sufficiently induced during the run. Under the current study conditions, the probiotic was safe to use, and did not affect gut- or immune-associated parameters, or intestinal symptoms in a healthy population. The probiotic might reduce tissue damage, but more studies are warranted.

This manuscript represents the second phase of a clinical trial designed to examine the effects of knee joint immobilization and retraining on muscle strength and mass. In Phase 2, we examined sex differences in the recovery of multiple indices of muscle quality after a resistance training-based rehabilitation program. Following 1 week of immobilization, 27 participants (16 males, 11 females) exhibiting weakness underwent twice weekly resistance training sessions designed to re-strengthen their left knee. Unilateral retraining sessions utilizing leg press, extension, and curl exercises were conducted until participants could reproduce their pre-immobilization knee extension isometric maximal voluntary contraction (MVC) peak torque. Post-immobilization, both sexes demonstrated impaired MVC peak torque (males = -10.8%, females = -15.2%), specific torque (-9.8% vs. -13.1%), echo intensity of the vastus lateralis (+6.9% vs. +5.9%) and rectus femoris (+5.9% vs. +2.1), and extracellular water/intracellular water ratio (+7.8% vs. +9.0%). The number of retraining sessions for peak torque to return to baseline for males (median = 1, mean = 2.13) versus females (median = 2, mean = 2.91) was not significantly different, though the disparity in recovery times may be clinically relevant. Following retraining, specific torque was the only muscle-quality indicator that improved along with MVC peak torque (males = 20.1%, females = 22.4%). Our findings indicate that measures of muscle quality demonstrate divergent recovery rates following immobilization, with muscle mass lagging behind improvements in strength. Greater immobilization-induced strength loss among females suggests that sex-specific rehabilitation efforts may be justified.