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

Heat exposure's effect on glucose tolerance depends on the amount of body exposed, likely relating to autonomic nervous system balance. We assessed how partial-body heat exposure at two different levels of the lower extremities affects glucose tolerance and autonomic nervous system balance, measured via heart rate variability. We hypothesized feet-heating would improve glucose tolerance without affecting heart rate variability, while calf-heating would worsen glucose tolerance and decrease heart rate variability compared to a thermoneutral control condition. In a randomized, controlled, crossover trial, healthy participants' (N = 31, 23(3) years, 45% male) glucose tolerance was measured in (A) thermoneutral; (B) feet-heating; and (C) calf-heating conditions. Every 30 min for 2 h, blood glucose, heart rate, heart rate variability, tympanic temperature, thermal comfort scores, and blood pressure were measured. There were significant interactions between condition and time for blood glucose (F (4.6,72.6) = 2.6, p = 0.036), heart rate (F (3.4, 54.5) = 3.5, p = 0.017), heart rate variability (F (4.3,63.2) = 7.5, p < .0001), tympanic temperature (F (8, 268) = 2.4, p = 0.014), and thermal comfort scores (F (8, 248) = 22.1, p < 0.0001). Calf-heating increased 90 min glucose (+12 (95% confidence interval, CI: 3-21) mg/dL, p = 0.013) and decreased heart rate variability throughout (mean decrease: 13%-22%, p < 0.007), while feet-heating lowered 90 min glucose (-7 (95% CI: -16 to +1) mg/dL, p = 0.090) without affecting heart rate variability (p = 0.14-0.99). Blood pressure and body temperature were similar between conditions, but heart rate and thermal comfort scores increased with heating. Calf-heating worsens, while feet-heating may improve, glucose tolerance. Changes in heart rate variability coincided with changes in glucose tolerance despite unchanged body temperature. Whether heart rate variability can be used to monitor autonomic nervous system balance during heating to optimize its acute effect on glycemic indices should be further explored.

We used data from NHANES 1988-1994 to examine associations between animal and plant protein usual intakes and IGF-1 concentration with mortality from all causes, cancer, and cardiovascular disease (CVD). Adult data (N = 15 937) were linked with mortality data (N = 3843 events) through 2006. Usual intakes for protein were estimated using the multivariate Markov Chain Monte Carlo method. Hazard ratio (HR) models were fit for mortality types (all-cause, cancer, and CVD) with protein intake measures (per 1 g increase) and IGF-1 concentration (N = 5753). There were no associations between animal protein (HR = 0.99; 95% confidence interval (CI): 0.98-1.01; P = 0.29) or plant protein (HR = 1.02; 95% CI: 0.95-1.10; P = 0.55) intake for all-cause mortality. Similar results were seen for CVD mortality and animal protein (HR = 1.02; 95% CI: 0.99-1.04; P = 0.14) and plant protein (HR = 1.01; 95% CI: 0.91-1.13; P = 0.81). There was an (inverse) association between cancer mortality and animal protein (HR = 0.95; 95% CI: 0.91-1.00; P = 0.04) but no relationship with plant protein (HR = 1.08; 95% CI: 0.93-1.24; P = 0.30). We found no association between concentrations of IGF-1 (N = 5753) for all-cause mortality (HR = 1.00; 95% CI: 0.99-1.00; P = 0.81), CVD mortality (HR = 0.99; 95% CI: 0.99-1.00; P = 0.53) or cancer mortality (HR = 1.00; 95% CI: 0.99-1.00; P = 0.76). Our results remained unchanged when the sample was separated into younger (<65 years) and older (>65, or between 50 and 65 years) cohorts. Our data do not support the thesis that source-specific protein intake is associated with greater mortality risk; however, animal protein may be mildly protective for cancer mortality. Mortality risk was not associated with circulating IGF-1 in any age group.

Monocarboxylates, transported by monocarboxylate transporters (MCTs), have been proposed to influence energy homeostasis and exhibit altered metabolism during exercise. This study investigated the association between the Asp490Glu (T1470A) (rs1049434) polymorphism of the SLC16A1 (MCT1) gene and changes in body composition in males and females with overweight or obesity. The 173 participants (56.6% females) completed a 6-month randomized controlled trial, being assigned to the Supervised Exercise group (strength, endurance, or strength plus endurance training) or the Physical Activity (PA) Recommendations group. Participants were genotypically categorized as Asp/Asp (TT), Asp/Glu (TA), or Glu/Glu (AA). ANCOVA analysis showed main effects for genotype and interaction genotype × group (p < 0.05) for several variables, especially in females. Asp/Asp (TT) females showed greater reductions in total fat mass (-29.30 ± 8.75% change), percentage of body fat (-17.50 ± 8.06% change), and body weight (-13.90 ± 2.62% change) compared with Glu/Glu (AA) (p ≤ 0.020; d ≥ 0.18) and Asp/Glu (TA) (p ≤ 0.050; d ≥ 0.16) females, but only within the PA Recommendations group. Data indicated higher decreases in lean body mass of the Asp/Asp (TT) compared to Glu/Glu (AA) in females (p = 0.067, η² _p = 0.067) and to Asp/Glu (TA) in males (p = 0.026; η² _p = 0.101). Our investigation suggests an association of the single-nucleotide polymorphism with body composition changes especially in females following exercise recommendations, highlighting the importance of supervised training to offset genetic predisposition for different weight loss. Differences in males only appeared for lean body mass, suggesting sex differences for this genetic association. The study underscores the potential influence of MCT1 functionality on human adaptations to weight loss interventions. ClinicalTrials.gov information: registry name, Nutrition and Physical Activity for Obesity (PRONAF); registration number, NCT01116856.

Older adults (OA) accumulate a greater amount of sedentary time (ST) compared to other subgroups of the population, which is associated with deleterious effects on multiple health outcomes and mortality. This study compared absolute sedentary behavior time (ASBT), which is generally used in studies, to relative SB time (RSBT), defined as the percentage of daily wake time, for their respective association with health conditions and multimorbidity. Two-thousand-four-hundred-sixty-one older adults (65-79 years) participated in the Canadian Health Measures Survey (2007-2017) and wore an accelerometer for ≥4 days, including a weekend day. Information regarding six health condition categories was extracted: cancer, cardiovascular, metabolic, musculoskeletal, psychological, and pulmonary. We combined these health conditions to create a multimorbidity variable. Participants were divided into ASBT quartiles and RSBT quartiles. Comparing the most sedentary (Q4) to the least sedentary (Q1) groups, we found no significant associations with any health conditions for ASBT. However, the same comparison for RSBT showed that RSBT-Q4 (the most sedentary; n = 660), compared to RSBT-Q1 (n = 660), was associated with a significant (p < 0.01) greater prevalence of cancer (160 > 110), cardiovascular (422 > 326), metabolic (276 > 194), and musculoskeletal (407 > 345), as well as multimorbidity (462 > 350). After adjusting for confounding factors (moderate to vigorous physical activity, housing, income, education level, relationship status, accelerometer wear season, and status of drinking and smoking), these associations persisted with the exception of musculoskeletal conditions. These results demonstrate that RSBT could be more appropriate to capture the association between a sedentary lifestyle and health profiles in older adults.

Excess liver fat (LF) is associated with low cardiorespiratory fitness (CRF), low physical activity, and a deteriorated cardiometabolic health profile including increased visceral adipose tissue (VAT). Whether the association between LF and CRF is mediated by visceral adiposity is unknown. We studied the contribution of VAT to the relationship between CRF and LF in asymptomatic women and men. The sample included 320 participants (43% women) who underwent LF quantification by magnetic resonance spectroscopy. VAT was measured by magnetic resonance imaging, CRF using maximal cardiorespiratory exercise testing, and moderate-to-vigorous intensity physical activity (MVPA) using a 3-day journal. Mean age was 50.3 ± 8.6 years, waist circumference was 89.3 ± 11.4 cm, and LF content was 4.3 ± 5.7%. LF was inversely correlated with CRF (p < 0.0001), MVPA (p < 0.05) and cardiometabolic health score (p < 0.0001), and positively related with VAT (p < 0.0001) in both sexes. Significantly higher levels of VAT (p < 0.0001) and subcutaneous adipose tissue (p < 0.0001) and a worsening cardiometabolic health score (p < 0.05) and CRF (p = 0.0001) were found across increasing sex-specific tertiles of LF levels. Lower levels of LF (p < 0.01) and VAT (p < 0.0001) and a higher cardiometabolic health score (p < 0.0001) and MVPA (p < 0.05) were noted across increasing sex-specific CRF tertiles. Multivariable regression analyses showed that visceral adiposity explained the majority of the variance in LF in both sexes (p < 0.0001). Finally, serial mediation analyses revealed that VAT but not body fat percentage was a mediator in the relationship between CRF and LF in both sexes. Thus, visceral adiposity appears to be an important mediator in the relationship between CRF and LF, even after controlling for total adiposity.

An undergraduate degree in kinesiology is one of the requirements to become a registered kinesiologist in Ontario, Canada. This study examined the alignment among 31 four-year honours degrees offered at 18 post-secondary institutions across Ontario and competencies associated with the profession of kinesiology. Curricula were analyzed against 14 essential competencies set by the College of Kinesiologists of Ontario and nine additional competencies related to the practice of kinesiology. The type of course (core or elective), presence of a lab, and lab hours per week were recorded. All degrees evaluated covered 79% (11/14) of the essential competencies and 33% (3/9) of the additional competencies. Notably, only five essential competencies and no additional competencies were universally met through core coursework alone; coverage occurred via core courses, electives, or a combination. Lab components were consistently associated with anatomy, biomechanics, exercise physiology, and assessment courses. Hands-on training hours, especially placement/clinical experience, varied significantly among degrees. Overall, these data highlight curricular breadth and variability in kinesiology degrees, and the diversity of elective choices to prepare students for the range of opportunities available to them after graduation. Kinesiology as a profession has a broad scope of practice and kinesiology degrees are not directly aligned with this role.

High-intensity resistance and impact training (HiRIT) may be more effective than low- to-moderate-intensity resistance training for improving bone health. However, it is unclear if women want to participate in HiRIT interventions. We developed an electronic survey and distributed it to Canadian women aged 40-60 years via social media. The primary objective was to understand how women in peri-menopause, early post-menopause, and late post-menopause perceive resistance training and their interest in participating in a HiRIT protocol designed to reduce bone loss and menopausal symptoms. Our second objective was to determine whether current exercise preferences, motivators, and barriers differed across the menopause continuum. The survey included questions to determine menopausal status, exercise perceptions and preferences, and demographics. 1648 women responded to the advertisements, 1007 started the survey, 996 consented, 975 were eligible, and 739 completed the survey. Of the completed respondents, 628 respondents were in peri-menopause (46.7%), early post-menopause (31.5%), or late post-menopause (21.8%). 86.5% of women expressed interest in participating in a resistance training protocol to improve bone health, and 71.8% were interested in participating in a HiRIT study targeting bone health and menopause symptoms. Key motivators of exercise were improving or maintaining general health (17.4%) and strength (15.2%). The main barriers were lack of time (23.6%) and cost (14.3%), with no differences between menopausal status. Peri- and post-menopausal women are interested in resistance training, aiming to improve bone health and reduce menopausal symptoms. This information will be used to develop a HiRIT program for women during the menopause transition.

The purpose of this study was to investigate whether quercetin ingestion increases the decline in muscle contractile capacity due to a single resistance exercise session at differing intensities. Thirty-eight older adults took part in this study. They were divided into three intensity groups: low- (LI), moderate- (MI), and high-intensity (HI) groups. Each participant completed two single resistance exercise sessions of resistance exercise at 40 (LI), 60 (MI), or 80 (HI) percent of maximal voluntary contraction. Before each session, they ingested either a placebo or quercetin glycoside (500 mg). Motor unit behavior and electrically elicited contraction torque were measured by high-density electromyography and neuromuscular electrical stimulation at pre-ingestion, post-ingestion, and post-exercise. Quercetin ingestion decreased the motor unit recruitment thresholds from pre- to post-ingestion (p < 0.001). The decline in electrically elicited contraction torque following exercise was greater with quercetin than placebo ingestion in LI and MI groups (low: p = 0.014; moderate: p = 0.025), but not in the HI group (p = 0.792). The greater the decline of electrically elicited contraction torque following exercise by quercetin ingestion, the greater the decrease in the recruitment threshold of motor units with a higher threshold by quercetin ingestion in LI and MI groups (low: p = 0.047, rs = 0.566; moderate: p = 0.011, rs = 0.692), but not in the HI group (p = 0.228). These results suggest that quercetin ingestion accelerates the decline in muscle contractile capacity following low- or moderate-intensity resistance exercise, possibly due to the additional recruitment of higher-threshold motor units.