Cortisol and insulin behaviors during an ultramarathon event: are they real markers of extreme exertion?

"BACKGROUND: The current work aimed to describe and compare the cortisol and insulin concentrations behavior and rate of perceived exertion (RPE) during a 115 km ultramarathon race. METHODS: Nine ultrarunners (eight males) were evaluated six times (0, 37, 60, 76, 89 and 115 km). At each moment, saliva samples (for cortisol and insulin assessment) and RPE (CR10 scale) were collected. Statistical analysis included correlation, one-way repeated measure ANOVA, and Statistical Parametric Mapping to define discrete and continues changes and compare cortisol, insulin and RPE profiles. RESULTS: Our main findings revealed an early peak in cortisol and RPE, accompanied by a decline in insulin responses (402±49 min of the race, P<0.05). Cortisol and insulin only showed magnitude differences with inverse behaviors until ~6% (7 km) of the ultramarathon duration. Cortisol and RPE presented similar behaviors, rising from the beginning of the race and remaining elevated throughout the race (η2=0.91 and η2=1.0, P<0.001). Insulin levels decreased when the race started, remaining below 60% of baseline values from the midpoint to the end of the race (P=0.04). CONCLUSIONS: The study showed an imbalance in the catabolic/anabolic hormone profile during an ultramarathon race, with a prominence in catabolic state. It should be considered in the ultramarathon races preparation and participation due to its possible detrimental effect on the athlete’s health.

Combined low-carbohydrate diet and long-term exercise in hypoxia in type 2 diabetes: A randomized controlled trial protocol to assess glycemic control, cardiovascular risk factors and body composition

Background: Cardiovascular disease is the leading cause of mortality associated with diabetes, which is characterized by chronic hyperglycemia. Low-carbohydrate diet has gained popularity as an intervention in patients with type 2 diabetes mellitus, acting to improve glycemic profile and serum lipids. In its turn, exercise in hypoxia induces specific adaptations, mostly modulated via hypoxia-induced transcription factor signaling cascade, which increases with exposure to altitude, and promotes angiogenesis, glycogen supply, glucose tolerance, and raises GLUT-4 expression. Aim: Given that hyperglycemia decreases HIF-1 and it is better controlled when following a low-carbohydrate diet, this study aims to examine the hypothesis that a combination of both low-carbohydrate diet and chronic exercise in hypoxia in type 2 diabetes mellitus is associated with improved glycemic control and cardiovascular parameters, whose protocol is described. Methods: Patients with type 2 diabetes mellitus ( n=48) will be recruited and randomized into one of the three groups: (a) Control group: Control diet (low-fat and moderate-carbohydrate diet)+exercise in normoxia; (2) exercise in hypoxia group: Control diet+exercise in hypoxia; (3) intervention group: Low-carbohydrate diet (low-carbohydrate and high-fat diet)+exercise in hypoxia. Before and after 8 weeks of interventions, cardiopulmonary tests (Bruce protocol), body composition and blood pressure will be evaluated. Blood samples will be collected to measure hypoxia-induced transcription factor, C-reactive protein, glycemic and lipid profiles. Summary: This will be the first trial to examine the isolated and combined effect of chronic exercise in hypoxia and low-carbohydrate diet in type 2 diabetes mellitus. This trial will help to fill a significant research gap, guide future research and contribute to the combined nutrition and exercise approach to type 2 diabetes mellitus. </jats:p

The effect of handlebar height and bicycle frame length on muscular activity during cycling: a pilot study

The cycling literature is filled with reports of electromyography (EMG) analyses for a better understanding of muscle function during cycling. This research is not just limited to performance, as the cyclist’s goal may be rehabilitation, recreation, or competition, so a bicycle that meets the rider’s needs is essential for a more efficient muscular activity. Therefore, the purpose of this study was to understand the contribution of the activity of each of the following muscles: TD (trapezius descending), LD (latissimus dorsi), GM (gluteus maximus), and AD (anterior deltoid) in response to different bicycle-rider systems (handlebar height; bicycle frame length) and intensities in a bicycle equipped with a potentiometer. Surface EMG signals from muscles on the right side of the body were measured. A general linear model test was used to analyze the differences between muscle activation in the test conditions. Effect sizes were calculated using a partial Eta2 (η 2 ). The level of significance was set at 0.05. Muscle activation of different muscles differs, depending on the cycling condition (Pillai’s trace = 2.487; F (36.69) = 9.300; p < 0.001. η 2 = 0.958), mostly during low intensities. In high intensities, one specific pattern emerges, with a greater contribution of GM and TD and weaker participation of LD and AD, enhancing the cycling power output.info:eu-repo/semantics/publishedVersio

Correction: Kindlovits et al. Eight Weeks of Intermittent Exercise in Hypoxia, with or without a Low-Carbohydrate Diet, Improves Bone Mass and Functional and Physiological Capacity in Older Adults with Type 2 Diabetes. Nutrients 2024, 16, 1624

In the original publication [...]</jats:p

Severe community-acquired pneumonia in the intensive care unit

Introduction Community-acquired pneumonia remains a common condition worldwide. It is associated with significant morbidity and mortality. The aim of this study was to evaluate conditions that could predict a poor outcome

Seleção preliminar da mangueira

Studies on evaluation of 19 mango selections and cultivars are reported. Data are presented on yields and fruit characteristics. Observations were made and data taken on color, size and shape, weight and volume, embryony, peel thickness and adherence, flavor, texture and fiber content, juice, soluble solids and sugars, acidity, pH, and ratio of soluble solids to acidity. The following five varieties were selected as most desirable: 'Afonsa Pairi', 'Extrema' and 'Zoologia' for the fresh market, 'Monserrate' for late season of maturity and 'Sabre' because it is polyembryonic and comes true from seed. A brief description is given of these varieties.Estudo de 19 seleções ou cultivares de mangueira. Os resultados preliminares incidem sobre a produtividade e as seguintes características físicas, químicas e organolépticas definidoras da qualidade da fruta: coloração; dimensões e forma; volume e peso; embrionia; espessura e aderência da casca; aroma e sabor; textura; fibra; sumo, sólidos e açúcares; acidez, pH e sólidos solúveis/acidez. A apreciação conjunta das características estudadas permitiu a seleção preliminar das seguintes variedades: 'Afonsa Pairi', 'Extrema' e 'Zoologia', utilizáveis para consumo em fresco. Selecionaram-se ainda a 'Monserrate' e a 'Sabre' - a primeira, por ser relativamente tardia; e a segunda, por ser poliembriônica. Finalmente, apresenta-se uma breve descrição destas cultivares