Applied Physiology, Nutrition, and Metabolism最新文献

Alternate-day fasting (ADF) is a nutritional intervention with modulatory and overall protective effects, but its role in the gastrointestinal (GI) tract is still uncertain. The aim of this study was to investigate the influence of ADF on the metabolic patterns and morphofunctional motility of the GI tract in rats. Thirty-two male Wistar rats were allocated into groups: control for 15 days (CON 15, n = 8), control for 30 days (CON 30, n = 8), ADF for 15 days (ADF 15, n = 8), and ADF for 30 days (ADF 30, n = 8). Blood glucose, body weight, and food and water consumption were measured. Frequency and amplitude of gastric contractions as well as gastric emptying time, small intestinal transit time, and cecum arrival time were measured. Intestinal histomorphometric, relative weight of organs, lipidogram, and leptin levels were also evaluated. ADF decreased water consumption and food consumption. The weight gain decreased; however, the relative kidney weight increased. ADF triggered an increase in the amplitude of gastric contractions and accelerated gastric emptying. However, small intestinal transit time was delayed in both ADF groups. Total cholesterol, triglycerides, non-HDL cholesterol, and very low-density lipoprotein cholesterol levels decreased, whereas villus height, depth of the crypts and thickness of the circular, and longitudinal muscular layers of intestine increased after ADF. In conclusion, our results showed ADF exert an effect on both metabolism and GI motility and impacts on overall digestive functions.

Ice hockey players are susceptible to COVID-19 because of close contact and poor arena ventilation. Preventive strategies include reducing arena crowding, practice strategies that reduce clustering of players, at-home rapid tests, symptom screening, and face mask or vaccine recommendations for spectators, coaches, and players. Face masks have little effect on physiological responses or performance and reduce COVID-19 transmission, but shifts should be shortened later in periods to reduce perceived exertion and players should be encouraged to assume a classic "hockey stance" when puck handling to improve peripheral vision. These strategies are important to prevent cancelation of practices or games, which have important physical and psychological benefits.

The objective of this study was to explore the experiences and perspectives of individuals with chronic health conditions who had an adverse event (AE) as a result of resistance training (RT). We conducted web conference or telephone-based one-on-one semi-structured interviews with 12 participants with chronic health conditions who had an AE as a result of RT. Interview data were analyzed using the thematic framework method. Six themes were identified: (1) personal experiences with aging influence perceptions of RT; (2) physical and emotional consequences of AEs limit activities and define future RT participation; (3) injury recovery defines the severity of AE; (4) health conditions influence the perceived risks and benefits of participating in RT; (5) RT setting and trained supervision influence exercise behaviors and risk perceptions; and (6) experiencing a previous AE influences future exercise behavior. Despite participant awareness of the value and benefits of RT in both the context of aging and chronic health conditions, there is concern about experiencing exercise-related AEs. The perceived risks of RT influenced the participants' decision to engage or return to RT. Consequently, to promote RT participation, the risks, not just the benefits, should be properly reported in future studies, translated, and disseminated to the public. Novelty: -To increase the quality of published research with respect to AE reporting in RT studies. -Health care providers and people with common health conditions will be able to make evidence-based decisions as to whether the benefits of RT truly outweigh the risks.

Leukocyte cell-derived chemotaxin-2 (LECT2) and fibroblast growth factor 21 (FGF21) are hepatokines that are regulated by energy balance and mediate insulin sensitivity and glycaemic control. This cross-sectional study examined the independent associations of cardiorespiratory fitness (CRF), moderate-to-vigorous intensity physical activity (MVPA), and sedentary time with circulating LECT2 and FGF21. Data were combined from two previous experimental studies in healthy volunteers (n = 141, male = 60%, mean ± SD age = 37 ± 19 years, body mass index (BMI) = 26.1 ± 6.3 kg·m^-2). Sedentary time and MVPA were measured via an ActiGraph GT3X + accelerometer, while magnetic resonance imaging quantified liver fat. CRF was assessed using incremental treadmill tests. Generalized-linear models examined the association of CRF, sedentary time, and MVPA with LECT2 and FGF21 while controlling for key demographic and anthropometric variables. Interaction terms explored the moderating influence of age, sex, BMI, and CRF. In the fully adjusted models, each SD increase in CRF was independently associated with a 24% (95% CI: -37% to -9%, P = 0.003) lower plasma LECT2 concentration and 53% lower FGF21 concentration (95% CI: -73% to -22%, P = 0.004). Each SD increase in MVPA was independently associated with 55% higher FGF21 (95% CI: 12% to 114%, P = 0.006), and this relationship was stronger in those with lower BMI and higher levels of CRF. These findings demonstrate that CRF and wider activity behaviours may independently modulate the circulating concentrations of hepatokines and thereby influence inter-organ cross-talk.

There is a popular belief that meat consumption is necessary to optimize adaptations to strength training (ST), but evidence to support this hypothesis is scarce. Therefore, this study aimed to compare ST adaptations in lacto-ovo-vegetarians (LOV) and non-vegetarians (NV) with adjusted protein intake per meal. Sixty-four LOV and NV performed 12 weeks of ST and were instructed to ingest at least 20 g of protein in each main meal during the experimental period. Quadriceps femoris muscle thickness (QFMT), knee extension one-repetition maximum (1RM), and isometric peak torque (PT), as well as participants' body composition were assessed before and after the intervention. Dietary intake was assessed throughout the study. After 12 weeks, similar increases in QFMT (LOV: 9.2 ± 5.4; NV: 5.5 ± 8.1 mm), knee extension 1RM (LOV: 24.7 ± 11.1; NV: 21.6 ± 9.8 kg), and PT (LOV: 29.8 ± 33.4; NV: 17.5 ± 19.4 N m) and lean body mass (LOV: 1.3 ± 0.9; NV: 1.4 ± 1.4 kg), alongside a decrease in body fat mass (LOV: -0.5 ± 1.6; NV -0.8 ± 1.6 kg) were observed in both groups at the end of the training period (p < 0.05). LOV had lower protein consumption than NV throughout the study (p < 0.05), but participants reached intake of at least 1.2 g of protein/kg/day during the experimental period. In conclusion, LOV and NV displayed similar improvements in muscle mass, strength, and in body composition after 12 weeks of ST, suggesting that meat consumption and higher protein intake in NV did not bring about further benefits to early adaptations to ST. This study was registered in Clinical Trials (NCT03785002) on 24 December 2018.

Milk-based proteins are a common choice of post-exercise nutrition to enhance exercise recovery and adaptation. Peri-exercise milk protein ingestion may attenuate exercise-induced muscle damage (EIMD), which is a particular risk to untrained individuals. However, most research has been conducted with males, and due to potential sex differences in EIMD, research with both sexes is required. This parallel-group randomized controlled trial examined the impact of milk protein ingestion on recovery from EIMD. Untrained males and females performed a single bout of leg-based resistance exercise and consumed a milk protein (MILK-PRO: n = 4 males, n = 8 females) or isoenergetic control (CON: n = 4 males, n = 8 females) supplement over 4 days post-exercise (17 doses total). Maximum strength was assessed ≥3 wk pre- and 72 and 168 h post-exercise, and measures of leg circumference, range of motion, muscle soreness, pressure-pain threshold (PPT), and serum creatine kinase concentration ([CK]) were conducted pre-, immediately post-, and 24, 48, 72, and 168 h post-exercise. Resistance exercise induced mild muscle damage that was not attenuated with MILK-PRO relative to CON. Peak increases in [CK] and reductions in PPT were greater in males compared with females. Changes in other markers were comparable between sexes. We conclude that moderate resistance exercise in naïve individuals induces muscle damage without compromising muscle strength. We support sex differences in EIMD and emphasize the need for further research with both sexes. Milk protein ingestion was not beneficial for recovery from EIMD, thus alternative management strategies should be investigated. This trial was prospectively registered at ClinicalTrials.gov PRS (protocol ID: 290580A).

This study aimed to compare the effects of an 8-week creatine (CR) or placebo (PL) supplementation on muscle strength, thickness, endurance, and body composition employing different training paradigms with blood flow restriction (BFR) vs. traditional resistance training (TRAD). Seventeen healthy males were randomized between the PL (n = 9) and CR (n = 8) groups. Participants were trained unilaterally utilizing a within-between subject bicep curl exercise where each arm was allocated to TRAD or BFR for 8 weeks. Muscular strength, thickness, endurance, and body composition were evaluated. Creatine supplementation promoted increases in muscle thickness in TRAD and BFR compared with their placebo counterparts, however, without a significant difference between treatments (p = 0.349). TRAD training increased maximum strength (1 repetition maximum (1RM)) compared with BFR after 8 weeks of training (p = 0.021). Repetitions to failure at 30% of 1RM were increased in the BFR-CR group compared with the TRAD-CR group (p = 0.004). Repetitions to failure at 70% 1RM were increased from weeks 0-4 (p < 0.05) and 4-8 (p < 0.05) in all groups. Creatine supplementation exerted a hypertrophic effect when utilized with TRAD and BFR paradigms and increased muscle performance at 30% 1RM when utilized in conjunction with BFR. Therefore, creatine supplementation seems to amplify muscle adaptation following a BFR program. Registered in the Brazilian Registry of Clinical Trials (ReBEC), under the registration number: RBR-3vh8zgj.

Upon arrival in Canada, immigrants are thrust into a new food environment, which is at an advanced stage of the nutrition transition continuum, encompassing reduced physical activity, sedentary lifestyles, and energy dense diets. In addition to the influence of readily available energy dense foods, immigrant children's food environments may also be impacted by limited availability of traditional foods, economic-constraints, time-constraints, parents' cooking skills, parents' child feeding styles, and school food environments. The study involved in-depth interviews with 22 immigrant parents regarding their family experiences of the food and nutrition environment, along with 22 participants from settlement agencies, community schools, English-as-a-second-language programmes, and healthcare organizations. Many newcomers shared experiences that highlighted drastic changes to their food environment upon arrival, including reduced access to open air fresh produce markets, increased access to large supermarkets, fast-paced lifestyles, and the pervasive presence of fast foods and snack foods. Some parents indicated that food purchase decisions were impacted by children's demands and that their children's school environments affected the types of foods their children would eat. A few service providers mentioned negative impacts on breastfeeding, and the change in physical environment as part of the nutrition environment due to association with vitamin D status. The early years are a pivotal time in the development of eating patterns; so supportive food and nutrition environments in homes, communities, and schools can ensure that children develop healthy eating habits to support long-term health.

Although sex-associated differences in energy metabolism in adults are well-characterized, developmental sex-specific changes in skeletal muscle metabolism are largely unknown. This study investigated sex differences in high-energy phosphate, glycolytic, and mitochondrial enzyme activities and metabolite transporter protein levels in mouse skeletal muscles during the early postnatal period (day 10), post-weaning (day 28), sexual maturity (day 56), and adult life (day 140). No significant sex-specific differences were observed on days 10 and 28, except for glucose transporter (GLUT) 4 level. The hexokinase, phosphofructokinase, and lactate dehydrogenase activities of skeletal muscle were higher and the citrate synthase, cytochrome c oxidase, and β-hydroxyacyl-CoA dehydrogenase activities were lower in female mice than those in male mice on days 56 and 140. The GLUT4 and FAT/CD36 protein levels were higher and the monocarboxylate transporter 4 level was lower in the skeletal muscles of female mice than those of male mice, particularly on days 56 and 140. At 140 days of age, the respiratory exchange ratio during treadmill running (15 m/min, 60 min) was lower in females than that in males, despite no sex differences at rest. In summary, sex differences were not evident in the early postnatal and post-weaning periods but became apparent after the mice reached sexual maturity. These findings indicate that sexually mature animals are a better model for investigating sex differences, particularly in the context of studying energy metabolism in mice.