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

Despite the general population seeking out exercise professionals and the strong interest of other healthcare providers in referring patients to exercise professionals, what characterizes an "exercise professional" is poorly understood. The purpose of this study was to summarize the required qualifications and certifications described in job advertisements hiring an "Exercise Professional" in Canada. A common career finding website (Indeed) and other relevant organizations were searched for job advertisements. The specific search terms were "Kinesiology", "Kinesiologist", "Exercise Professional", and "Exercise Physiologist". Job advertisements that were hiring an exercise professional and described some exercise related duties were included for content analysis. n = 177/1364 unique job advertisements met inclusion criteria. Job titles were grouped into six main categories: Kinesiologist (n = 88/177), Personal Trainer (n = 49/177), Fitness Coach/Instructor (n = 38/177), Strength and Conditioning Specialist (n = 5/177), Exercise Physiologist (n = 4/177), and other (n = 31/177). Most positions required (n = 101) or preferred (n = 36) a Kinesiology degree, while n = 48/92 (88 Kinesiology and 4 Exercise Physiologist positions) indicated a need/interest in applicants having a membership with a provincial Kinesiology association/affiliation, n = 8/92 a Clinical Exercise Physiologist certification, and n = 6/92 a general "Kinesiology certification". This emphasizes the need for unique requirements of exercise professional positions and guidelines for the (di)similar scope of practice across exercise professional training.

Wildland firefighters can work at high intensity in hot environments for extended periods of time. The resulting heat strain may be modified by the environmental conditions (i.e., ambient temperature and humidity [RH]) even at equal wet-bulb globe temperatures (WBGTs). This investigation assessed if a hot and dry condition would create greater strain than moderate and high humidity at equivalent WBGT (28 °C). Twelve participants (age 24 ± 2 year) walked at 40%-50% maximum aerobic capacity for 90 and 40 min separated by a 20 min rest in dry (40 °C, 20% RH), moderate-humidity (34 °C, 50% RH), and high-humidity (29 °C, 90% RH) conditions wearing fire-resistant jacket, pants, gloves, and helmet with the neck and face exposed. Peak core temperature was higher in moderate-humidity (38.9 ± 0.2 °C, p = 0.01) and high-humidity (38.9 ± 0.6 °C, p < 0.01) than dry condition (38.5 ± 0.3 °C). Average net heat gain was less in dry (33 ± 22 W) compared to moderate-humidity (38 ± 23 W, p < 0.01) and high-humidity (39 ± 28 W, p < 0.01). Peak heart rate (174 ± 14 bpm, p = 0.94), physiological strain index (7.7 ± 1.4 score, p = 0.99), perceived exertion (8 ± 2 rating, p = 0.97), and perceptual strain index (7.3 ± 1.6 score, p = 0.99) were not different in high-humidity compared to the dry condition (167 ± 19 bpm, 6.9 ± 1.3 score, 6 ± 2 rating, 7.3 ± 1.7 score, respectively). Whole-body sweat rate (15 ± 6 mL/min, p = 0.58) and thermal sensation (7 ± 1 rating, p = 0.37) were not different. Hiking in a humid condition while wearing protective garments creates greater exertional heat strain compared to a dry condition of equivalent WBGT. Wildland firefighters should consider extra strategies to mitigate hyperthermia when humidity is high.

Brain-derived neurotrophic factor (BDNF) is a growth factor associated with a range of neurological, cardioprotective, and metabolic health benefits. While passive heat stress has been observed to increase circulating BDNF, the BDNF response to a given stressor may be attenuated with increasing age. To investigate the influence of age on the BDNF response to heat stress, we compared BDNF responses to daylong (9 h) exposure to hot ambient conditions (40 °C, 9% relative humidity) between 19 young (range: 19-31 years; 9 women) and 37 older adults (61-78 years; 12 women). We also explored whether cumulative thermal strain (area under the curve of rectal and mean body temperatures) impacted comparisons. Serum BDNF concentrations were assessed at pre- and end-exposure using enzyme-linked immunosorbent assays. Circulating BDNF concentrations increased from baseline in both groups (P < 0.001), but end-exposure concentrations were 2594 [1555-3633] pg/mL lower in older than young adults (P < 0.001). This age-related difference persisted, albeit to a lesser magnitude, after accounting for the lower pre-exposure BDNF levels in older adults (baseline-adjusted between-group difference: 1648 [667-2630] pg/mL; P < 0.001). Additionally, the BDNF response was not related to indices of thermal strain (P ≥ 0.562), and baseline-adjusted between-group differences were not appreciably altered by adjusting for area under the curve of rectal (1769 [714-2825] pg/mL; P = 0.002) or mean body temperatures (1745 [727-2763] pg/mL; P = 0.001). Our study is the first to demonstrate an age-related reduction in the BDNF response to prolonged passive heat exposure, which informs our wider understanding of how environmental stressors influence BDNF responses in older adults.

Athletes may engage in weight cycling-successive episodes of weight loss and weight (re)gain-for performance reasons, but risk metabolic adaptations and regaining more fat that was lost (fat overshoot). This study aimed to assess the influence of a complete weight cycling episode on body composition, thermoregulation, and metabolism in athletes, considering sex and the type of sport practiced. Forty-eight athletes (28 males, 20 females) engaged in combat (n = 23), strength (n = 12), or endurance (n = 13) sports were examined under three experimental conditions (weight maintenance, weight loss, weight (re)gain) during a weight cycling episode using their habitual strategies. Body composition (dual-energy X-ray absorptiometry), core body temperature (telemetric temperature sensor), energy expenditure and substrate oxidation at rest and during moderate exercise (indirect calorimetry), and energy intake (48 h food record) were assessed. Overall, athletes lost 4.4 ± 2.3% body weight, 12.2 ± 10.6% fat mass, and 2.6 ± 2.3% fat-free mass (p < 0.001). All variables returned to baseline values during the regain period, and a higher fat mass regain was observed in endurance than combat athletes (p < 0.01). During weight loss, a transient increase in lipid and decrease in carbohydrate oxidation occurred at rest and during exercise (p < 0.001). Energy expenditure and core body temperature remained unchanged across the three experimental conditions, and no specific sex effect was observed. Overall, no apparent body weight nor fat overshoot was observed in athletes after a complete weight cycling episode. Nonetheless, the greater fat mass gain in endurance, compared with combat athletes, highlights a need for further specific long-term studies in this population. Clinical Trial registration: NCT04107545.

The present study aimed to compare peak oxygen uptake (V̇O₂peak), peak heart rate (HRpeak), and peak O₂pulse during an incremental and a verification test performed on the same day in hand-cyclists with spinal cord injury (SCI). Eight competitive SCI hand-cyclists (age: 23 ± 2.7 years; V̇O₂peak: 36.3 ± 14.0 mL.kg^-1.min^-1) performed a maximal incremental handcycling test and a verification test to exhaustion at 100% of the peak speed on an oversized treadmill. The V̇O₂peak, HRpeak, and peak O₂pulse (i.e., VO₂/HR) were compared between incremental and verification tests. Absolute and relative V̇O₂peak obtained in the verification test (2.51 ± 0.96 L.min^-1; 36.3 ± 14.0 mL.kg.min^-1) were significantly higher than values obtained in the incremental test (2.24 ± 0.79 L.min^-1; 33.5 ± 12.9 mL.kg.min^-1; P < 0.05). The mean differences (95% CL) of absolute and relative V̇O₂peak between tests were 8.2% (3.3%-13.2%) and 10.9% (4.3%-18.1%), respectively. There was no difference in HR peak (incremental: 169 ± 24 bpm; verification 167 ± 25 bpm; P = 0.130). Peak O₂pulse from the verification test (14.6 ± 4.7 mL.beat^-1) was higher than incremental test (13.0 ± 3.8 mL.beat^-1; P = 0.007). In conclusion, the verification test elicited greater V̇O₂peak and O₂pulse than a two-phase incremental test despite the similar HRpeak. This indicates that for this progressive protocol lasting ≥25 min, the verification phase adds value to determining V̇O₂peak in SCI athletes.

Motor unit firing rate (MUFR) and pennation angle were measured concurrently in males and females from submaximal to maximal intensities. Thirty participants, (16 female, 14 male) performed isometric dorsiflexion contractions at 20%, 40%, 60%, 80%, and 100% of maximal voluntary contraction (MVC). During each contraction, measures of MUFR were obtained via surface electromyography decomposition, and muscle fiber pennation angle and fascicle length were obtained via ultrasound. There was no significant interaction effect of sex and contraction intensity present for mean MUFR (p = 0.24), pennation angle (p = 0.98), or fascicle length (p = 0.81). Males had greater mean MUFR (p < 0.001), pennation angle (p = 0.02), and fascicle length (p = 0.03) compared to females. In general, mean MUFR (p < 0.001) and pennation angle (p < 0.02) increased with increasing contraction intensity; however, fascicle length (p = 0.30) was similar across contraction intensities. There were no significant relationships between mean MUFR and pennation angle for males (r = 0.18, p = 0.13) or females (r = 0.20, p = 0.09), nor between mean MUFR and fascicle length for males (r = 0.20, p = 0.10) or females (r = 0.21, p = 0.07). Although sex-related differences in MUFR, pennation angle, and fascicle length were present, there were no relationships between MUFR and the muscle properties. These results suggest that sex-related differences in mean MUFR may not be associated with the sex-related differences in the muscle architectural properties currently investigated.

Plant-based meat alternative (PBMA) consumption has increased amid significant reformulation efforts. Although reformulated PBMAs have characteristics that could provide cardiometabolic benefits over animal proteins (e.g., higher fiber, certain phytochemicals/micronutrients), their acute health effects remain unclear. Moreover, whether baseline adiposity (i.e., normal weight or overweight/obesity) affects the response to PBMA intake is unknown. We conducted a randomized crossover study where healthy participants (N = 30) with a normal body mass index (BMI; 18.5-24.9 kg/m²; n = 15) or overweight/obese BMI (>25.0 kg/m²; n = 15) consumed two high-fat meals on separate occasions containing a reformulated PBMA (Beyond Meat Cookout Classic^TM) or similar beef product (80% lean ground beef). Meals were matched for energy (950 kcal) and macronutrient matched (71 g fat/31-35 g carbohydrate/41-42 g protein). At each trial, an intravenous catheter was inserted and biomarkers of inflammation (i.e., interleukin (IL)-6, tumor necrosis factor (TNF)-α), intestinal permeability (i.e., lipopolysaccharide binding protein (LBP), soluble CD14 (sCD14), LBP:sCD14 ratio), and metabolic factors (triglycerides, HDL-C, glucose) were measured at baseline and hourly for 4 hours post-meal. Paired t tests and two-way mixed model ANOVAs were used to examine within-meal-condition changes and differences in incremental area under the curve (iAUC) across meal and BMI conditions, respectively. Regardless of protein source, high-fat meals increased IL-6, TNF-α, LBP, sCD14, LBP:sCD14, and triglycerides and decreased HDL-C (p ≤ 0.01). In BMI subgroup analyses, an interaction effect for IL-6 iAUC was observed (p_MealxBMI < 0.05), but post hoc analyses were not significant (p ≥ 0.07). Overall, inclusion of a reformulated PBMA within a high-fat meal resulted in a similar cardiometabolic response to a nearly identical meal containing animal protein (ClinicalTrials.gov:NCT06445296).

The objective of this study was to develop and evaluate a food choices assessment score (FCAS) measuring alignment with 2019 Canada's Food Guide (CFG) and Canada's Dietary Guidelines (CDG) using a non-quantitative food frequency questionnaire (FFQ) data. Cross-sectional data from the Canadian Health Measures Survey (2016-2019), including 6459 participants (≥19 years) and a non-quantitative FFQ (∼100 food items) were used. Content and construct validity and assessing reliability were used to evaluate the FCAS, including a comparison of mean FCAS among Canadian subgroups, calculating the FCAS for high quality diet menus, investigating the consistency of the FCAS with the Dietary Approaches to Stop Hypertension (DASH), as a healthy diet linked with lower cardiometabolic risks, and estimating Cronbach's alpha for reliability. The FCAS consisted of nine components for a total of 80 points. The FCAS captured the key recommendations of the 2019 CFG/CDG. Mean (SE) FCAS of the adult Canadian population was 29.3 (0.4) (/80) and was higher in females 32.2 (0.4) and non-smokers 30.3 (0.3) compared to males 26.7 (0.4) and smokers 23.6 (0.9), respectively (p < 0.0001). FCAS yielded high scores for healthy menu samples of CDG (80/80) and DASH (70/80) diets. FCAS was correlated with DASH diet score (r = 0.83). Cronbach's alpha was found to be moderate (0.5), as expected, which confirmed the multidimensionality of the FCAS components in reflecting different characteristics of diet quality. These analyses suggest adequate validity with multidimensional consistency of the 2019 CFG/CDG FCAS as a new tool for use with non-quantitative FFQ data.