Leucine metabolites do not induce changes in phase angle, bioimpedance vector analysis patterns, and strength in resistance trained men.

We aimed to assess the effects of off-the-shelf leucine metabolite supplements on phase angle (PhA), bioimpedance vector analysis (BIVA) patterns and strength during an 8-week resistance training protocol. Fifty-three male participants were allocated into 4 groups: α-hydroxyisocaproic acid (n = 12, age = 30.9 ± 9.3 years), ß-hydroxy-ß-methylbutyrate free acid (n = 12, age = 31.0 ± 9.3 years), calcium ß-hydroxy-ß-methylbutyrate (n = 15, age = 32.1 ± 5.2 years) or placebo (n = 14, age = 28.9 ± 6.6 years). Bioimpedance parameters and 1-repetition maximum (1RM) for back squat and bench press were assessed at baseline and at the end of weeks 4 and 8. Additionally, fat-free mass and fat mass were evaluated by dual-energy X-ray absorptiometry. No statistically group by time interactions were found, even adjusting for age. PhA and vector did not change over the training period, while time-dependent increases were observed for 1RM back squat and 1RM bench press. A direct association was observed between PhA and 1RM bench press changes (whole sample), while PhA and strength were correlated throughout the study, even when adjusting for fat-free mass and percentage of fat mass. Leucine metabolites have no effect on PhA, BIVA patterns or strength during an 8-week resistance training program, in resistance trained subjects. The trial was registered at ClincicalTrials.gov: NCT03511092. Novelty: Supplementation with leucine metabolites is not a supplementation strategy that improves bioelectrical phase angle, cellular health, and strength after an 8-week resistance training program. When consuming a high protein diet, none of the α-hydroxyisocaproic acid, ß-hydroxy-ß-methylbutyrate free acid, and calcium ß-hydroxy-ß-methylbutyrate metabolites resulted in an ergogenic effect in resistance trained men.

Perfil sérico proteico de vacas Holandesas no período de transição / Serum protein profile of Holstein cows during the transition period

O objetivo deste trabalho foi avaliar, de forma longitudinal, o perfil sérico proteico de 13 vacas Holandesas durante o período de transição. Amostras de sangue (n=78) foram coletadas semanalmente, da segunda semana pré-parto (M-2) até a terceira semana pós-parto (M3), para determinação do perfil sérico proteico, por meio de teste bioquímico (proteínas séricas totais - PT) e eletroforese em gel de poliacrilamida SDS-PAGE, para as outras proteínas analisadas. Os valores de PT diminuíram de forma gradativa (P=0,000) de M-2 (6,4g/dL) a M0 (6,2g/dL), aumentando nos momentos subsequentes (M3=7,3g/dL). As concentrações da IgG de cadeia pesada (M-2=919,4; M-1=1074,5mg/dL) e de cadeia leve (M-2=393,9; M-1=466,7mg/dL) foram menores no pré-parto em relação ao pós-parto (M1=1283,3; M2=1374,2 e M3=1630,3 mg/dL para IgG pesada e M1=463,4; M2=573,7; M3=651,8mg/dL para IgG leve). Para a IgA, houve diminuição nos valores (P=0,001), de M-2 (51,9mg/dL) a M1 (34,0mg/dL), e aumento em M2 (45,4g/dL) e M3 (62,6g/dL). Os valores de haptoglobina (Hp) e ceruloplasmina (Cp) aumentaram (P=0,000) de M-2 (Hp=16,6mg/dL; Cp=8,6mg/dL) a M3 (Hp=60,9mg/dL; Cp=127,1mg/dL). A albumina apresentou ligeiras variações durante o período de transição (P=0,000), enquanto a transferrina sérica (P=0,101) e a glicoproteína ácida (P=0,105) foram estáveis. O escore de condição corporal (ECC) também foi analisado durante o período de transição, verificando-se diferença (P=0,003) entre M-2 (ECC=4,0) e M1 (ECC=3,0). Foi relatada ainda a ocorrência de distocias (4/13), retenção de placenta (1/13) e hipocalcemia (1/13) no dia da parição (M0) e infecções uterinas (5/13) e cetose (1/13) ocorridas no pós-parto. Concluiu-se, portanto, que houve aumento nas concentrações séricas de Hp e Cp e diminuição nos valores de imunoglobulina e transferrina em vacas Holandesas no período de transição, relacionados às doenças ocorridas nesse período e ao elevado ECC, promovendo modificações metabólicas e imunossupressão.(AU)

The aim of this study was to evaluate longitudinally the serum protein profile of 13 Holstein cows during the transition period. Blood samples (n=78) were taken weekly, from the second week before parturition (M-2) to the third week after parturition (M3) for determination of serum protein profile by biochemical tests (total serum protein - PT) and SDS-PAGE electrophoresis, for the other proteins analyzed. PT values decreased gradually (P = 0.000) from M-2 (6.4g/dL) to M0 (6.2g/dL), increasing in subsequent moments (M3 = 7.3g/dL). The concentrations of the heavy chain (M-2=919.4; M-1=1074.5mg/dL) and the light chain of IgG (M-2=393.9; M-1=466.7mg/dL) were lower in pre-calving compared to post calving (M1= 1,283.3; M2=1,374.2 and M3=1,630.3 mg/dL for the heavy chain, and M1=463.4; M2=573.7 and M3=651,8 mg/dL for the light chain of IgG). For IgA there was a decrease in the values (P=0.001), from M-2 (51.9mg/dL) to M1 (34.0mg/dL), and increase in M2 (45,4g/dL) and M3 (62,6g/dL). The values of haptoglobin (Hp) and ceruloplasmin (Cp) increased (P=0,000) from M-2 (Hp=16.6mg/dL; Cp=8.6 mg/dL) to M3 (Hp=60.9mg/dL; Cp=127.1mg/dl). Albumin showed slight variations during the transition period (P=0.000), while the serum transferrin (P=0.101) and acid glycoprotein (P=0.105) were stable. Body condition score (BCS) was also analyzed during the transition period, checking the difference (P=0.003) between M-2 (ECC= 4.0) and M1 (ECC=3.0). It was also reported the occurrence of dystocia (4/13), retained placenta (1/13) and hypocalcemia (1/13) on the day of calving (M0) and uterine infections (5/13) and ketosis (1/13) occurring in the post calving. In conclusion, there was an increase in serum Hp and Cp, and a decrease in the immunoglobulins and transferrin amounts in Holstein cows during the transition period, related to diseases occurring during this period and the high BCS, promoting metabolic changes and immunosuppression.(AU)

Estimating the inhaled dose of pollutants during indoor physical activity.

BACKGROUND: It is undeniable that many benefits come from physical activity. People exercise in fitness centers to improve their health and well-being, prevent disease and to increase physical attractiveness. However, these facilities join conditions that cause poor indoor air quality. Moreover, increased inhalation rates during exercise have influence on inhaled doses of air pollution. OBJECTIVES: This study aims to calculate the inhaled dose of air pollutants during exercise, by estimating minute ventilation of participants and measuring air pollutant concentrations in fitness centers. METHODS: Firstly, the 20 participants performed an incremental test on a treadmill, where heart rate and minute ventilation were measured simultaneously to develop individual exponential regression equations. Secondly, heart rate was measured during fitness classes and minute ventilation was estimated based on the calculated regression coefficients. Finally, the inhaled dose of air pollutants was calculated using the estimated minute ventilation and the concentrations of the pollutants measured in a monitoring program performed in 63 fitness classes. RESULTS: Estimated inhaled doses were higher in aerobic classes than in holistic classes. The main difference was registered for PM10 inhaled dose that presented an average ratio between aerobic and holistic classes greater than four. Minute ventilation and PM10 concentrations in aerobic classes were, on average, 2.0 times higher than in holistic classes. Results showed that inhalation of pollutants is increased during heavy exercise, demonstrating the need to maintain high indoor air quality in fitness centers. CONCLUSIONS: This study illustrates the importance of inclusion minute ventilation data when comparing inhaled doses of air pollution between different population groups. This work has estimated for the first time the minute ventilation for different fitness classes. Also constitutes an important contribution for the assessment of inhaled dose in future studies to be performed in fitness centers.

VO2 kinetics during heavy and severe exercise in swimming.

The purpose of this study was to describe the VO2 kinetics above and below respiratory compensation point (RCP) during swimming. After determination of the gas-exchange threshold (GET), RCP and VO(2max), 9 well-trained swimmers (21.0 ± 7.1 year, VO(2max)=57.9 ± 5.1 ml.kg (- 1).min (- 1)), completed a series of "square-wave" swimming transitions to a speed corresponding to 2.5% below (S - 2.5%) and 2.5% above (S+2.5%) the speed observed at RCP for the determination of pulmonary VO2 kinetics. The trial below (~2.7%) and above RCP (~2%) was performed at 1.28 ± 0.05 m.s (- 1) (76.5 ± 6.3% VO(2max)) and 1.34 0.05 m.s (- 1) (91.3 ± 4.0% VO(2max)), respectively. The time constant of the primary component was not different between the trials below (17.8 ± 5.9 s) and above RCP (16.5 ± 5.1 s). The amplitude of the VO(2)slow component was similar between the exercise intensities performed around RCP (S - 2.5%=329.2 ± 152.6 ml.min (- 1) vs. S+2.5%=313.7 ± 285.2 ml.min (- 1)), but VO(2max) was attained only during trial performed above RCP (S-2.5%=91.4 ± 5.9% VO(2max) vs. S+2.5%=103.0 ± 8.2% VO(2max)). Thus, similar to the critical power during cycling exercise, the RCP appears to represent a physiological boundary that dictates whether VO(2) kinetics is characteristic of heavy- or severe-intensity exercise during swimming.