RESUMO
Bioelectrical impedance (BIA) and ultrasound (US) have become popular for estimating body fat percentage (BF%) due to their low cost and clinical convenience. However, the agreement of these devices with the gold-standard method still requires investigation. The aim was to analyze the agreement between a gold-standard %BF assessment method with BIA and US devices. Twenty-three men (aged 30.1 ± 7.7 years, weighing 82.5 ± 14.9 kg, 1.77 ± 0.05 m tall) underwent dual-energy X-ray absorptiometry (DXA), BIA (tetrapolar) and US (three-site method) %BF assessments. Pearson and concordance correlations were analyzed. A T-test was used to compare the means of the methods, and Bland-Altman plots analyzed agreement and proportional bias. Alpha was set at <0.05. The Pearson coefficients of BIA and US with DXA were high (BIA = 0.94; US = 0.89; both p < 0.001). The concordance coefficient was high for BIA (0.80) and moderate for US (0.49). The BF% measured by BIA (24.5 ± 7.5) and US (19.4 ± 7.0) was on average 4.4% and 9.6% lower than DXA (29.0 + 8.5%), respectively (p < 0.001). Lower and upper agreement limits between DXA and BIA were -1.45 and 10.31, while between DXA and US, they were 2.01 and 17.14, respectively. There was a tendency of both BIA (p = 0.09) and US (p = 0.057) to present proportional bias and underestimate BF%. Despite the correlation, the mean differences between the methods were significant, and the agreement limits were very wide. This indicates that BIA and US, as measured in this study, have limited potential to accurately measure %BF compared to DXA, especially in individuals with higher body fat.
RESUMO
This study aimed to verify the time course recovery of muscle edema within the quadriceps femoris and functional performance after lower-body single- and multi-joint exercises. For this within-participant unilateral and contralateral experimental design, fourteen untrained young males performed a unilateral knee extension exercise (KE), and a unilateral leg press (LP) exercise in a counterbalanced order. At pre-, post-, 24 h, 48 h, 72 h, and 96 h after exercise, the peak torque (PT), unilateral countermovement jump (uCMJ) performance, and rectus femoris (RF) and vastus lateralis (VL) muscle thicknesses were recorded in both legs. The PT decreased immediately after (p = 0.01) both exercises (KE and LP) and was fully recovered 24 h after KE (p = 0.38) and 48 h after LP (p = 0.68). Jump height and power, in the uCMJ, followed the same PT recovery pattern after both exercises. However, vertical stiffness (Kvert) was not affected at any time point after both protocols. The RF thickness increased after both exercises (p = 0.01) and was fully restored 48 h after KE (p = 0.86) and 96 h after LP (p = 1.00). The VL thickness increased after both exercises (p = 0.01) and was fully restored 24 h after LP (p = 1.00) and 48 h after KE (p = 1.00). The LP exercise, compared to KE, induced more prolonged impairment of functional performance and delayed recovery of RF muscle edema. However, the VL edema-induced muscle swelling recovery was delayed after the KE exercise. The different recovery kinetics between functional performance and muscle damage should be taken into consideration depending on the objectives of the next training sessions.
RESUMO
Com o objetivo de avaliar sistemas de corte, épocas de semeadura e cultivares de soja no consórcio das culturas de sorgo e soja na entrelinha, na composição da forragem, foi instalado em Lavras-MG, no Departamento de Agricultura da UFLA, um ensaio em blocos casualizados em esquema fatorial 5x3x3, compreendendo cinco épocas de semeadura do sorgo, três cultivares de soja e três sistemas de corte. As épocas de semeadura, alteraram significativamente a composição mineral (P, K, Ca e Mg) com rendimentos decrescentes à medida que atrasava a semeadura. As cultivares de soja proporcionaram aumentou no acúmulo de nutrientes. O sistema de corte rente ao solo apresentou maiores rendimentos dos minerais analisados (P, K, Ca e Mg). No sistema consorciado foi observada forragem mais rica em nutrientes em relação ao monocultivo do sorgo.
With the objective to evaluate systems for cutting, sowing dates and cultivars of soybean crops in the consortium of sorghum and soybeans in between, the composition of the forage, was installed in Lavras-MG, the Department of Agriculture UFLA, a test block randomized in a 5x3x3 factorial, with five times of sowing of sorghum, three soybean cultivars and three systems of cut. The sowing dates sorghum, significantly altered the mineral composition (P, K, Ca e Mg) with diminishing returns as the late sowing. The soybean cultivars increased in the accumulation of nutrients. The system of cut close to the soil showed higher yields of analyzed minerals (P, K, Ca e Mg). Consortium system was observed in more forage rich in nutrients in the sorghum monoculture