ABSTRACT
O objetivo do estudo foi realizar um breve comunicado sobre a adoção da densidade com uma nova métrica de quantificação de cargas no treinamento de força. Descrevemos como quantificá-la e destacamos as possíveis implicações da sua manipulação. Uma vez que considera o intervalo de recuperação entre as séries - onde podem ocorrer processos metabólicos importantes, como a ressíntese de fosfocreatina - a densidade pode ser um parâmetro representativo da magnitude do estresse metabólico induzido pelas sessões. Recomendamos que treinadores e pesquisadores da área de ciências do esporte passem a reportar quantificar e reportar a densidade dos treinos. Técnicas de treinamento que manipulam as pausas entre as séries, repetições e exercícios, como os treinos em circuito, o restpause, cluster training, intra-set rest e/ou inter-repetion rest, podem ter novas análises e, consequentemente, resultados interessantes a serem reportados.(AU)
The aim of the study was to provide a short communication about the adoption of density as a new metric to quantify strength training loads. We describe how quantify and highlighted the possible implications of density manipulation. Since considers the rest interval between sets - where important metabolic process such as phosphocreatine resynthesizes may occurs density may represent the magnitude of metabolic stress induced by training session. In this sense, is recommended that sports sciences coach's and researchers report the training density. Training techniques that manipulate the rest intervals between sets, repetitions, and exercises, such as circuit tra ining, rest pause, cluster training, intra-set rest, and/or inter-repetition rest may have new analysis, and consequently interesting results to be reported.(AU)
Subject(s)
Humans , Male , Female , Adult , Phosphocreatine/metabolism , Stress, Physiological , Resistance Training/methods , Skeletal Muscle EnlargementABSTRACT
Objective:To investigate the mechanism underlying the inhibiting effect of low-glucose combined with palmitic acid on human colon cancer cells and its influence on the radiosensitivity.Methods:Under the treatment of low-glucose, palmitic acid and low-glucose combined with palmitic acid, the treatment condition that significantly inhibited the proliferation of SW480 was screened by CCK-8 assay. The reactive oxygen species (ROS) level, mitochondrial membrane potential and apoptosis rate were detected by flow cytometry. The changes in the radiosensitivity were detected by immunofluorescence-based γ-H 2AX quantification and colony formation assay. The protein expression level was detected by Western blot. Results:Compared with the control group, the condition of low-glucose combined with 120μmol/L palmitic acid significantly inhibited the proliferation of SW480 cells ( P<0.01). The expression levels of CPT1a, PFKFB3 and PKM were significantly up-regulated, the expression levels of NDUFV1, NDUFV2 and NDUFS1 were remarkably down-regulated, the ROS level was significantly increased and the ATP level was considerably reduced in the cells under metabolic stress (all P<0.01). After irradiation, the number of γ-H 2AX foci was significantly increased ( P<0.05), and the D 0 value was significantly reduced ( P<0.01), the ROS level was considerably increased ( P<0.001), the apoptosis rate was significantly increased ( P<0.001) and the expression level of γ-H 2AX protein was remarkably up-regulated ( P<0.01) in the low-glucose combined with 120μmol/L palmitic acid group. Pretreatment with NAC could reverse the changes of ROS, apoptosis and γ-H 2AX protein expression. Conclusions:The combination of low-glucose and palmitic acid can induce metabolic stress in SW480 cells, inhibit tumor proliferation and increase the radiosensitization when combined with radiotherapy by inducing the generation of ROS and DNA damage.
ABSTRACT
This study aimed to elucidate the effects of exercise intensity on stretch-shortening cycle (SSC) function of the lower limbs after cycling. Ten male triathletes performed a cycling graded test to determine the ventilatory threshold (VT) and two hopping-cycling (30 min of cycling at 90 or 110% VT)-hopping tests. The two hopping-cycling-hopping tests performed in random order. Power output (PO), heart rate (HR) and rate of perceived exertion (RPE) were monitored throughout the 30-min cycling. Blood lactate concentrations (BLa) were measured in order to assess metabolic stress. The SSC function was calculated as the ratio of the jump height to the time spent in contact with the ground (reactive strength index [RSI]). PO, HR and RPE values during cycling at 110%VT was higher than at 90%VT (p < 0.01). BLa value after the cycling at 110%VT was higher than at 90%VT (90%VT: 2.4±1.0 vs. 110%VT: 5.9±2.8 mmol/L, p < 0.01). Regardless of the cycling exercise intensity, the RSI significantly decreased after the cycling exercise (p < 0.01). The RSI remained decreased at 15 min after the cycling exercise (p < 0.05). These results demonstrated that the SSC function decreased after cycling. Exercise intensity during cycling is likely to have no effect on the decrease in SSC function.
ABSTRACT
@#This review aims to present an overview of current research findings on the possible effects of circadian rhythm (CR) disruption towards metabolic stress and mental health. CR can be described as an internal biological clock that regulates our body functions, based on our sleep/wake cycle. Any time that our normal 24-hour circadian rhythm is altered or interrupted, it will have physiological and psychological impacts. However, in today’s demanding working world, most of us are working defying the normal conditions without realising the significant drawbacks of it. Therefore, this review summarises the findings from several researches on the physiological (metabolic stress) and psychological (cognitive functioning and mental health) impacts of the CR disruption in order to assist people to have a holistic view on the effects of CR to our mind and body. Evidences that linked these aspects to health circumstances of shift workers have also been highlighted.
ABSTRACT
Energy intake excess in modern society contributes to the abrupt increase of type 2 diabetes. The sodium-glucose cotransport 2 (SGLT-2) inhibitors, a new class of hypoglycemic agents inhibit reabsorption of glucose and excrete excessive energy by the kidney and therefore ameliorate the metabolic stress. The relief of metabolic stress further improves blood glucose, lipid levels, so as blood pressure, insulin resistance and pancreatic β cell function, which would be associated with the protection of cardiovascular diseases and amelioration of renal function.
ABSTRACT
BACKGROUND: Intraoperative stress may evoke various changes in hormonal secretion and autonomic nervous system activity. We designed this study to investigate the effect of combined spinal-epidural anesthesia on stress hormone responses. METHODS: Thirty women more than 60 years of age, undergoing bilateral total knee replacement surgery were studied. Patients were randomized to receive either general anesthesia (group I), or combined spinal-epidural anesthesia (group II). Blood samples were obtained immediately before anesthesia induction, immediately after skin incision, after first knee prosthesis insertion, and end of operation, immediately for measurement of cortisol, epinephrine, and norepinephrine. RESULTS: The plasma concentration of cortisol, epinephrine and norepinephrine were significantly lower in group II after the prosthesis insertion and at the end of operation, immediately. The plasma concentration of cortisol was significantly higher than basal values in both of two groups through the surgery. CONCLUSIONS: Combined spinal-epidural anesthesia has the blocking effect of releasing catecholamine during total knee replacement surgery and immediately after the surgery. The effect of combined spinal-epidural anesthesia on stress responses during total knee replacement is better than that of general anesthesia.