Hydration status after an ironman triathlon: a meta‐analysis

The Ironman is one of the most popular triathlon events in the world. Such a race involves a great number of tactical decisions for a healthy finish and best performance. Dehydration is widely postulated to decrease performance and is known as a cause of dropouts in Ironman. Despite the importance of hydration status after an Ironman triathlon, there is a clear lack of review and especially meta-analysis studies on this topic. Therefore, the objective was to systematically review the literature and carry out a meta-analysis investigating the hydration status after an Ironman triathlon. We conducted a systematic review of the literature up to June 2016 that included the following databases: PubMed, SCOPUS, Science Direct and Web of Science. From the initial 995 references, we included 6 studies in the qualitative analysis and in the meta-analysis. All trials had two measures of hydration status after a full Ironman race. Total body water, blood and urine osmolality, urine specific gravity and sodium plasma concentration were considered as hydration markers. Three investigators independently abstracted data on the study design, sample size, participants’ and race characteristics, outcomes, and quantitative data for the meta-analysis. In the pooled analysis, it seems that the Ironman event led to a moderate state of dehydration in comparison to baseline values (SMD 0.494; 95% CI 0.220 to 0.767; p = 0.001). Some evidence of heterogeneity and consistency was also observed: Q = 19.6; I2 = 28.5%; τ2 = 2.39. The results suggest that after the race athletes seem to be hypo-hydrated in comparison to baseline values

Physical fitness and anthropometric characteristics in professional soccer players of the United Arab Emirates

AbstractObjectiveTo describe the anthropometric and physical fitness profiles of elite soccer players acting in the United Arab Emirates.MethodTwenty seven elite soccer players acting in the United Arab Emirates were underwent to an anthropometric evaluation, an incremental test in treadmill and performed the Running-Based Anaerobic Test (RAST).ResultsBody mass index and body fat percentage of the athletes were 23.1±2.0kg.m−2 11.6±2.1 %, respectively. Indirect maximum oxygen uptake (VO2max) was 62.3±5.1ml.kg−1.min−1, mean velocity at VO2max was 17.6±1.5km.h−1, ventilatory threshold (VT) of 13.8±0.8km.h−1, heart rate at VT of 173.1±8.6b.min−1, which represents of 91.2±2.8 % of maximum heart rate. RAST resulted in a maximum absolute power of 551.9±73.0 W, maximum relative power of 7.8±0.4W.kg−1, mean absolute power of 484.0±57.8W, and mean relative power of 6.8±0.2W.kg−1.ConclusionThe anthropometric profile of soccer players that act in the United Arab Emirates is similar to others around the world. However, regarding the physical fitness, results are still inconclusive, since findings from other studies suggest that the anaerobic power of our sample is alike or lower than other elite players throughout the world. Likewise indirect VO2max, especially given the acknowledged limitations of obtaining indirectly this variable. In addition, making an analysis by playing position, the results of this study are similar to previous research

Feruloyl esterase activity and its role in regulating the feruloylation of maize cell walls

Cell walls of grasses have ferulic acid (FA) ester-linked to the arabinosyl substitutions of arabinoxylan (AX). Feruloyl esterases (FAE) are carboxylic acid esterases that release FA from cell walls and synthetic substrates. Despite the importance of FA for cell wall recalcitrance and in response to biotic and abiotic stresses, the physiological function of plant FAEs remains unclear. Here, we developed a simple method for the determination of FAE activity (ZmFAE) in maize using the total protein extract and investigated its role in regulating the feruloylation of cell wall. The method includes a single protein extraction and enzymatic reaction with protein concentration as low as 65 mu g at 35 degrees C for 30 min, using methyl ferulate as the substrate. The methodology allowed the determination of the apparent K-m (392.82 mu M) and V-max (79.15 pkat mg(-1) protein). We also found that ZmFAE activity was correlated (r = 0.829) with the levels of FA in seedling roots, plant roots and leaves of maize. Furthermore, the exposure to osmotic stress resulted in a 50% increase in ZmFAE activity in seedling roots. These data suggest that FAE-catalyzed reaction is important for cell wall feruloylation during plant development and in response to abiotic stress. We conclude proposing a model for the feruloylation and deferuloylation of AX, which explains the role of FAE in regulating the levels of ester-linked FA. Our model might orient further studies investigating the role of plant FAEs and assist strategies for genetic engineering of grasses to obtain plants with reduced biomass recalcitrance

Acyl-homoserine Lactone from <i>Saccharum × officinarum</i> with Stereochemistry-Dependent Growth Regulatory Activity

Acyl-homoserine lactones (AHLs) are a class of compounds produced by Gram-negative bacteria that are used in a process of chemical communication called quorum sensing. Much is known about how bacteria use these chemical compounds to control the expression of important factors; however, there have been few reports about the presence and effects of AHLs in plants. In this study, the phytochemical study of leaves and culms of sugar cane (<i>Saccharum × officinarum</i>) led to the identification of <i>N</i>-(3-oxo-octanoyl)­homoserine lactone. Since the absolute configuration of the natural product could not be determined, both <i>R</i> and <i>S</i> enantiomers of <i>N</i>-(3-oxo-octanoyl)­homoserine lactone were synthesized and tested in sugar cane culms. The enantiomers caused changes in the mass and length of buds and roots when used at micromolar concentrations. Using the sugar cane RB96-6928 variety, the <i>S</i> enantiomer increased sprouting of roots more effectively than the <i>R</i> enantiomer. Furthermore, scanning electron microscopy showed that both the <i>R</i> and <i>S</i> enantiomers led to more stretched root cells compared with the control

Intradialytic isometric handgrip exercise does not cause hemodynamic instability: A randomized, cross‐over , pilot study

Hemodialysis (HD) patients experience hemodynamic instability and intradialytic exercise seems to attenuate it. This study aimed to verify the acute hemodynamic response to different intradialytic handgrip exercise intensities in HD patients. In a randomized, cross-over, experimental pilot study, eight patients completed two experimental sessions and one control in random order: (a) regular HD; (b) low-intensity isometric handgrip exercise; and (c) moderate-intensity isometric handgrip exercise. BP and heart rate variability were recorded immediately before and every 15 minutes. Isometric handgrip exercise protocols, regardless of the intensity, did not lead to significant changes in hemodynamic stability, nor when compared to the control condition (P > .05). The systolic BP and double product significantly increased immediately after the moderate-intensity protocol (122.0 ± 15.9 vs 131.3 ± 19.8, P < .05; 9094.7 ± 1705.7 vs 9783.0 ± 1947.9, P < .05, respectively) but returned to the pre-exercise values 10 minutes later. We conclude that intradialytic isometric handgrip exercise does not induce hemodynamic instability at low and moderate intensities.info:eu-repo/semantics/publishedVersio