Physical training, UCP1 expression, mitochondrial density, and coupling in adipose tissue from women with obesity.

BACKGROUND: Exercise training may improve energy expenditure, thermogenesis, and oxidative capacities. Therefore, we hypothesized that physical training enhances white adipose tissue mitochondrial oxidative capacity from obese women. OBJECTIVE: To evaluate mitochondrial respiratory capacity, mitochondrial content, and UCP1 gene expression in white adipose tissue from women with obesity before and after the physical training program. METHODS: Women (n = 14, BMI 33 ± 3 kg/m2 , 35 ± 6 years, mean ± SD) were submitted to strength and aerobic exercises (75%-90% maximum heart rate and multiple repetitions), 3 times/week during 8 weeks. All evaluated subjects were paired, before and after training for resting metabolic rate (RMR), substrate oxidation (lipid and carbohydrate) by indirect calorimeter, deuterium oxide body composition, and aerobic maximum velocity (Vmax ) test. At the beginning and at the ending of the protocol, abdominal subcutaneous adipose tissue was collected to measure the mitochondrial respiration by high-resolution respirometry, mitochondrial content by citrate synthase (CS) activity, and UCP1 gene expression by RT-qPCR. RESULTS: Combined physical training increased RMR, lipid oxidation, and Vmax but did not change body weight/composition. In WAT, exercise increased CS activity, decreased mitochondrial uncoupled respiration and mRNA of UCP1. RMR was positively correlated with fat-free mass. CONCLUSION: Physical training promotes an increase in mitochondrial content without changing tissue respiratory capacity, a reduction in mitochondrial uncoupling degree and UCP1 mRNA expression in WAT. Finally, it improved the resting metabolic rate, lipid oxidation and physical performance, independent of the body changing free, or fat mass in obese women.

Taurine supplementation increases irisin levels after high intensity physical training in obese women.

BACKGROUND: Irisin is a myokine/adipokine that under stimulus of physical exercise is able to improve thermogenic capacity in adipose tissue. Likewise, taurine supplementation has demonstrated similar effects on energy metabolism. Therefore, we hypothesized that taurine supplementation combined with physical training may induce an increase in irisin concentrations, optimizing energy metabolism in obese individuals. OBJECTIVE: To evaluate if taurine supplementation associated with a high intensity physical training program increases irisin levels in obese women. METHODS: double-blind study with 22 obese women (BMI 32.4 ±â€¯2.0 kg/m2, 36.6 ±â€¯6.4 years and sedentary) who were randomly divided into two groups, control group (GC, n = 14), exercised and supplemented with placebo (3 g of starch), and taurine group (GTAU, n = 8), exercised and supplemented with taurine (3 g). The subjects performed high intensity physical training, Deep Water Running (DWR), for 8 weeks, 3 times/week, for 50 min per training session, at 70-85% maximum heart rate. Resting metabolic rate (RMR) was evaluated by indirect calorimetry, body composition by deuterium oxide, plasma taurine by HPLC, plasma irisin by Multiplex Kit, and food consumption by food records. The results were analyzed by an ANOVA two way repeated measures mixed model, with the Sidak post hoc (p < 0.05). RESULTS: No changes were observed in body composition. DWR increased RMR independent of supplementation (p < 0.001) and irisin levels (pg/mL) showed a significant difference only in the GTAU in 1 h after exercise (p < 0.001). CONCLUSION: DWR associated with taurine supplementation resulted in increased plasma irisin concentrations after physical training in obese adult women.

Cocoa flavanol effects on markers of oxidative stress and recovery after muscle damage protocol in elite rugby players.

OBJECTIVES: Strenuous exercise can impair athletic performance due to muscular inflammation and oxidative stress. Antioxidants such as cocoa flavanols have been used as a supplement to prevent oxidative stress; however, the benefits of dietary antioxidants for athletic performance after muscle soreness (MS) is unclear. The purpose of this study was to examine the effects of cocoa flavanols after a MS inducing protocol. METHODS: In a randomized, double-blinded design, 13 male collegiate rugby players consumed either chocolate milk (CHOC) or chocolate milk with additional cocoa flavanols (CocoaCHOC) during a 7-d loading phase. MS was induced by a drop jump protocol on day 5 of the intervention. Athlete performance was assessed with vertical-jump and yo-yo tests and subjective measures of soreness 5 d before and 2 d post-MS protocol. Urinary markers of oxidative stress (isoprostanes) were assessed before and 48 h post-MS. RESULTS: No changes were observed between the groups over time for isometric torque (P = .63), vertical jump performance (P = .39), and yo-yo testing (P = .57) between the trials. No interaction was found in isoprostanes levels between the trials (CocoaCHOC baseline: 88 ± 0.38 pg/mL and 48 h post-MS: 81 ± 0.53 pg/mL; P = .82; and CHOC baseline: 98 ± 0.96 pg/mL and 48 h post-MS: 96 ± 0.38 pg/mL; P = .59). No main effect (treatment × time; P = .58) was observed for isoprostanes. Although not significant, the CocoaCHOC group ran 97 meters further than the CHOC group in the yo-yo test. CONCLUSIONS: Cocoa flavanols added to a post-exercise recovery beverage for 7 d has no oxidative stress or athletic performance benefits.

Effects of taurine supplementation in elite swimmers performance

AIM: Taurine is considered a semi-essential amino acid characterized by having various physiological functions in the body that modulate mechanisms of action involved in the muscle contraction process, increased energy expenditure, insulin signaling pathway, carbohydrate metabolism, and scavenging free radicals. These functions are crucial for aerobic exercise performance; thus, taurine supplementation may benefit athletes' performance. The objective of this study was to evaluate the effects of taurine supplementation on the resting energy expenditure and physical performance of swimming athletes. METHODS: In a double-blind study, 14 male swimmers were randomized into two groups: the taurine group (n = 7) and the placebo group (n = 7), which received 3 g per day of taurine or placebo in capsules during 8 weeks. Resting energy expenditure, plasma taurine, physical performance, anthropometry, dietary consumption were measured and an incremental test was performed to determine their maximal front crawl swimming performances before and after the 8-week period. RESULTS: The levels of serum taurine (p < 0.0001) and lactate (p = 0.0130) showed a significant increase in the taurine group; however, the other variables were not different. No changes were observed in the resting energy expenditure, mean speed performed, and the anaerobic threshold of the swimmers post-supplementation period. CONCLUSION: Supplementation of taurine increased plasma concentrations of this amino acid, but did not lead to significant changes in food intake, rest energy expenditure, and athletes' performance. However, the supplemented group presented a higher lactate production, suggesting a possible positive effect of taurine on the anaerobic lactic metabolism.(AU)

Metabolismo lipídico durante o exercício físico: mobilização do ácido graxo / Lipid metabolism during exercise: mobilization of fatty acid / Metabolismo de los lípidos durante el ejercicio: movilización del ácido graso

É sabido que os ácidos graxos são importante fonte de energia para contração muscular. As principais fontes metabólicas de energia derivadas dos lipídios são os ácidos graxos do tecido adiposo, os triglicerídeos intramusculares e os triglicerídeos circulantes do plasma. A contribuição de cada um depende do exercício realizado,duração, intensidade e estado de treinamento do indivíduo. O treinamento de longa duração provoca adaptações no organismo, como aumento da capacidade oxidativa dos músculos esqueléticos e maior participação dos lipídios como substrato energético durante o esforço, ocasionando possível melhora no desempenho do atleta. O objetivo do presente estudo foi investigar a regulação do metabolismo lipídico durante a realização do exercício físico.

It is known for a long time that fatty acids are important energy source for muscle contraction. The main sources of metabolic energy derived from lipids are free fatty acids from adipose tissue and intramuscular triglycerides circulating plasma triglycerides. The contribution of each one depends on the type of exercise done, duration, intensity and state of training of the individual. The endurance training provokes adaptations in the organism as, increase of the oxidative capacity of the skeletal muscles and, consequently bigger participation of the lipids as energetic substrate during realization of the effort, possibly causing an improvement in performanceof the athlete. The aim of the present study was to investigate regulationof the lipids metabolism, during the physical exercise.

Se sabe que los ácidos grasos son fuente importante de energía para la contracción muscular. Las principales fuentes de energía metabólica derivada de los lípidos son los ácidos grasos del tejido adiposo intramuscular y triglicéridos plasmáticos de triglicéridos circulantes. La contribución de cada uno depende del ejercicio realizado, duración, intensidad y nivel de entrenamiento del individuo. La formación a largo plazo provoca adaptaciones en el cuerpo, como aumento de la capacidad oxidativadel músculo esquelético y una mayor participación de los lípidos como sustrato energético durante el ejercicio, dando lugar a una posible mejora en el rendimiento deportivo. El propósito de este estudio fue investigar la regulación del metabolismo de los lípidos durante el curso del ejercicio.