Juçara (Euterpe edulis Martius) improves time-to-exhaustion cycling performance and increased reduced glutathione: A randomized, placebo-controlled, crossover, and triple-blind study

Purpose: To examine the effects of 7-days juçara powder intake on oxidative stress biomarkers and endurance and sprint cycling performances. Methods: In a randomized, placebo-controlled, crossover, and triple-blind study, 20 male trained cyclists were assigned to intake 10 g of juçara powder (JP) (240 mg anthocyanins) or placebo (PLA) for 7-days and performed a cycling time-to-exhaustion (TTE) A 5 s cycling sprint was performed before and after the cycling TTE. Blood oxidative stress biomarkers and lactate concentration where evaluated 1 hour before (T-1), immediately after (T0), and 1 hour after (T1) the cycling TTE. Results: The mean duration time for the cycling TTE was 8.4 ± 6.0% (63 ± 17 s) longer in the JP condition (JP: 751 ± 283 s) compared to PLA (688 ± 266 s) (P < 0.019). Two-way repeated measures ANOVA showed an increase in the JP condition for reduced glutathione (GSH) (P = 0.049) at T0 (P = 0.039) and T1 (P = 0.029) compared to PLA with a moderate effect size at T0 (d = 0.61) and T1 (d = 0.57). Blood lactate levels increased over time in both conditions (P ≤ 0.001). No differences were observed for the post-TTE sprint fatigue index, total phenols, protein carbonyls, and glutathione peroxidase activity. Conclusions: Seven-day intake of JP improved cycling endurance performance and increased GSH levels but had no effect on lactate and cycling sprint-induced fatigue

Physiological Predictors of Maximal Incremental Running Performance

Purpose: The aim of this study was to verify whether physiological components [vertical jumps (Squat Jump – SJ and Countermovement Jump – CMJ), eccentric utilization ratio (EUR) of vertical jumps, running economy (RE), metabolic cost (CMET), first and second ventilatory threshold (VT1 and VT2) maximal oxygen uptake (VO2MAX)] can predict maximal endurance running performance. Methods: Twenty male runners performed maximal vertical jumps, submaximal running at constant speeds, and maximal incremental running test. Before, we measured anthropometric parameters (body mass and height) and registered the training history and volume. SJ and CMJ tests were evaluated prior to running tests. Initially, the oxygen uptake (VO2) was collected at rest in the orthostatic position for 6 min. Soon after, a 10-min warm-up was performed on the treadmill at 10 km⋅h–1, followed by two 5-min treadmill rectangular tests at 12 and 16 km⋅h–1 monitored by a gas analyzer. After that, the runners performed a maximal incremental test, where the VT1, VT2, and VO2MAX were evaluated, as well as the maximum running speed (vVO2MAX). Thus, RE and CMET were calculated with data obtained during rectangular running tests. Multivariate stepwise regression analyses were conducted to measure the relationship between independent variables (height and power of SJ and CMJ, EUR; RE and CMET 12 and 16 km⋅h–1; VT1, VT2, and VO2MAX), as predictors of maximal running performance (vVO2MAX), with significance level at α = 0.05. Results: We found that VO2MAX and RE at 16 km⋅h–1 predict 81% of performance (vVO2MAX) of endurance runners (p < 0.001). Conclusion: The main predictors of the maximal incremental running test performance were VO2MAX and RE

Alimentação de leitoas pré-púberes com dietas contendo zearalenona Feeding of pre-pubertal gilts with diets containing zearalenone

O desempenho, o peso de alguns órgãos e a morfologia vulvar de leitoas pré-púberes, alimentadas por 28 dias com dietas contendo zearalenona, foram avaliados. O delineamento experimental utilizado foi inteiramente ao acaso, com dois tratamentos, dieta controle (DC) e dieta controle + 2mg kg-1 de zearalenona (DZ), e seis repetições cada. Não houve diferença (P>0,05) entre os tratamentos para consumo médio diário de ração (1,24 x 1,19kg), ganho médio diário de peso (0,68 x 0,71kg), conversão alimentar (1,86 x 1,71) e peso vivo (PV); (30,9 x 30,4kg). A zearalenona não alterou (P>0,05) os pesos absoluto e relativo do coração (137 x 141g e 0,45 x 0,45% PV), fígado (699 x 699g e 2,31 x 2,26%PV), rins (47 x 49g e 0,15 x 0,16%PV) e baço (166 x 171g e 0,55 x 0,55%PV). Houve aumento (PThe performance, the weights of some organs, and the vulvae morphology in pre-pubertal gilts fed diets containing zearalenone were evaluated during 28 days. The experimental design was completely randomized with two treatments (control diet, ZD - control diet + 2mg kg-1 of zearalenone) and six replications of each were done. No differences (P>0.05) between treatments for daily feed intake (1.24 x 1.19kg), average daily gain (0.68 x 0.71kg), feed conversion ratio (1.86 x 1.71), and live weight (30.9 x 30.4kg) were observed. Zearalenone did not change (P>0.05) the absolute and relative weights of heart (137 x 141g and 0.45 x 0.45%BW), liver (699 x 699g and 2.31 x 2.26%BW), kidneys (47 x 49g and 0.15 x 0.16%BW), and spleen (166 x 171g and 0.55 x 0.55% BW). However, zearalenone increased (P<0.05) the length (17 x 27cm) and weight (23 x 157g and 0.07 x 0.51%BW) of the reproductive tract. The final vulvae volume was 820% larger (P<0.05) in gilts fed diets containing zearalenone than those fed control diet (941 x 8658mm³/kgBW0.6). Results suggested that zearalenone and its metabolites have an estrogenic activity in pigs without changing the animal performance

Triceps Surae Muscle-Tendon Properties as Determinants of the Metabolic Cost in Trained Long-Distance Runners

Purpose: This study aimed to determine whether triceps surae’s muscle architecture and Achilles tendon parameters are related to running metabolic cost (C) in trained long-distance runners. Methods: Seventeen trained male recreational long-distance runners (mean age = 34 years) participated in this study. C was measured during submaximal steady-state running (5 min) at 12 and 16 km h–1 on a treadmill. Ultrasound was used to determine the gastrocnemius medialis (GM), gastrocnemius lateralis (GL), and soleus (SO) muscle architecture, including fascicle length (FL) and pennation angle (PA), and the Achilles tendon cross-sectional area (CSA), resting length and elongation as a function of plantar flexion torque during maximal voluntary plantar flexion. Achilles tendon mechanical (force, elongation, and stiffness) and material (stress, strain, and Young’s modulus) properties were determined. Stepwise multiple linear regressions were used to determine the relationship between independent variables (tendon resting length, CSA, force, elongation, stiffness, stress, strain, Young’s modulus, and FL and PA of triceps surae muscles) and C (J kg–1m–1) at 12 and 16 km h–1. Results: SO PA and Achilles tendon CSA were negatively associated with C (r2 = 0.69; p < 0.001) at 12 km h–1, whereas SO PA was negatively and Achilles tendon stress was positively associated with C (r2 = 0.63; p = 0.001) at 16 km h–1, respectively. Our results presented a small power, and the multiple linear regression’s cause-effect relation was limited due to the low sample size. Conclusion: For a given muscle length, greater SO PA, probably related to short muscle fibers and to a large physiological cross-sectional area, may be beneficial to C. Larger Achilles tendon CSA may determine a better force distribution per tendon area, thereby reducing tendon stress and C at submaximal speeds (12 and 16 km h–1). Furthermore, Achilles tendon morphological and mechanical properties (CSA, stress, and Young’s modulus) and triceps surae muscle architecture (GM PA, GM FL, SO PA, and SO FL) presented large correlations with C

Piglet birth weight, subsequent performance, carcass traits and pork quality: a meta-analytical study

The meta-analyses were carried out to study the effect of piglet birth weight on performance, carcass traits and pork quality. The database totaled 3294 piglets (28 articles published from 2000 to 2014). The piglets’ mean weight at birth was 1.45 kg. The weights were classified into three groups: heavy (average weight 1.80 kg), medium (1.48 kg) and light (1.09 kg). The publications selected for the meta-analyses presented results from experiments with at least two weight ranges at birth and organ weight and/or performance and/or carcass data. The piglets’ body and organ birth weights showed highly significant and positive correlations (P < 0.05); piglets of low birth weight also had (P < 0.05) light weight organs. The piglets’ birth weight was positively correlated (P < 0.05) with their body weight and weight gain in the all subsequent stages of production. Heavy piglets at birth were 6.6 kg heavier (P < 0.05) at slaughter (150 days of age) compared to light-born piglets. The age at which the piglets reached 110 kg body weight was (P < 0.05) 9.5 days in those born with medium and high weights, and 12.1 days in those born with light weight. Light weight piglets presented a relative belly weight at slaughter 0.5% higher (P < 0.05) than piglets with high birth weight. At slaughter, the weight of the ham of heavy-born piglets was (P < 0.05) 4.4% higher, and the heart and liver weight was (P < 0.05) 6.8% higher than those of light weight piglets; however, the other pork quality were not influenced (P < 0.05). The birth weight of piglets influences performance and in overall does not alter pork quality. However, when piglet weight at birth is greater than 1.50 kg performance is not influenced

Effect of photobiomodulation therapy on performance and running economy in runners: A randomized double-blinded placebo-controlled trial

The objective of this study was to evaluate effects of photobiomodulation therapy (PBMT) on the 3000 m running performance (primary outcome), running economy (RE), metabolic cost and ratings of perceived exertion during running (secondary outcomes). Twenty male endurance athletes performed 4-min treadmill rectangular test at 12 km.h-1 monitored by a gas analyser. After that, PBMT or placebo in each lower limb was applied, followed performed a maximum test of 3000 m. Immediately after 3000 m test, the athletes repeated the treadmill test. Another application of PBMT/placebo was done after the treadmill test, and athletes went back to the laboratory 24 h later to repeat the treadmill test. After a 72 h interval, athletes repeated all procedures with another treatment intervention (PBMT/placebo). Athletes performed the 3000 m running test ~7s faster when treated with PBMT with similar effort score compared placebo condition. The RE remains unchanged immediately post 3000 m running test, nonetheless RE measured post-24 h improved by 5% with PBMT application without changes in metabolic cost. The PBMT pre- and post-conditioning enhanced the 3000 m running performance and improved RE 24 h following the 3000 m test. However, no changes on ratings of perceived exertion and metabolic cost with the application of PBMT

Water-Based Concurrent Training Improves Peak Oxygen Uptake, Rate of Force Development, Jump Height, and Neuromuscular Economy in Young Women

The study investigated the effects of different intrasession exercise sequences on the cardiorespiratory and neuromuscular adaptations induced by water-based concurrent training in young subjects. Twenty-six healthy young women (25.1 ± 2.9 years) were placed into 2 water-based concurrent training groups: resistance before (RA, n 13) or after (AR, n 13) aerobic training. Subjects trained resistance and aerobic training during 12 weeks, 2 times per week performing both exercise types in the same training session. Peak oxygen uptake (Vo 2 peak), rate of force development (RFD) obtained during an isometric peak torque knee extension protocol, jump height, and neuromuscular economy (normalized electromyography at 80% of pretraining knee extension isometric peak torque) in young women were determined. After training, there was a significant increase (p < 0.001) in both RA and AR in the Vo 2 peak, with no differences between groups (7 vs. 5%). The maximal isometric knee extension RFD showed significant increases (p 0.003) after training (RA: 19 vs. AR: 30%), and both groups presented similar gains. In addition, the countermovement jump height also increased (p 0.034) after training (RA: 5% vs. AR: 6%), with no difference between groups. After training, there were significant improvements on vastus lateralis (p < 0.001) (RA: -13% vs. AR: -20%) and rectus femoris (p 0.025) (RA: -17% vs. AR: -7%) neuromuscular economy, with no difference between groups. In conclusion, 12 weeks of water-based concurrent training improved the peak oxygen uptake, RFD, jump height, and neuromuscular economy in young women independent from the intrasession exercise sequence