16 research outputs found
A Nutrition and Conditioning Intervention for Natural Bodybuilding Contest Preparation: Case Study.
Bodybuilding competitions are becoming increasingly popular. Competitors are judged on their aesthetic
appearance and usually exhibit a high level of muscularity and symmetry and low levels of body fat. Commonly used techniques to improve physique during the preparation phase before competitions include dehydration, periods of prolonged fasting, severe caloric restriction, excessive cardiovascular exercise and inappropriate use of diuretics and anabolic steroids. In contrast, this case study documents a structured nutrition and conditioning
intervention followed by a 21 year-old amateur bodybuilding competitor to improve body composition, resting and
exercise fat oxidation, and muscular strength that does not involve use of any of the above mentioned methods.
Over a 14-week period, the Athlete was provided with a scientifically designed nutrition and conditioning plan that
encouraged him to (i) consume a variety of foods; (ii) not neglect any macronutrient groups; (iii) exercise regularly
but not excessively and; (iv) incorporate rest days into his conditioning regime. This strategy resulted in a body
mass loss of 11.7 kg’s, corresponding to a 6.7 kg reduction in fat mass and a 5.0 kg reduction in fat-free mass.
Resting metabolic rate decreased from 1993 kcal/d to 1814 kcal/d, whereas resting fat oxidation increased from
0.04 g/min to 0.06 g/min. His capacity to oxidize fat during exercise increased more than two-fold from 0.24 g/min
to 0.59 g/min, while there was a near 3-fold increase in the corresponding exercise intensity that elicited the
maximal rate of fat oxidation; 21% V̇
O2max to 60% V̇ O2max. Hamstring concentric peak torque decreased (1.7 to 1.5 Nm/kg), whereas hamstring eccentric (2.0 Nm/kg to 2.9 Nm/kg), quadriceps concentric (3.4 Nm/kg to 3.7 Nm/kg) and quadriceps eccentric (4.9 Nm/kg to 5.7 Nm/kg) peak torque all increased. Psychological mood-state (BRUMS scale) was not negatively influenced by the intervention and all values relating to the Athlete’s mood-state remained below average over the course of study. This intervention shows that a structured and scientifically supported nutrition strategy can be implemented to improve parameters relevant to bodybuilding competition and importantly the health of competitors, therefore questioning the conventional practices of bodybuilding preparation
Effects of Branches on the Isothermal Crystallization of Copolymers Based on Poly(ϵ-caprolactone)
A linear poly(ϵ-caprolactone), PCL, and grafted copolymers based on poly(2-hydroxyethylmethacrylate) and poly(ϵ-caprolactone) are used to study the effect of branches on PCL crystallization process. Copolymers are synthetized by a combination of ring opening polymerization and reversible addition fragmentation chain transfer polymerization, showing molar masses between 32 000 and 46 000 g mol −1 with M w /M n lower than 1.19. Isothermal crystallization kinetic is performed by Differential Scanning Calorimetry combining Avrami and Hoffman-Weeks theories. Regarding to Avrami parameters, copolymers exhibited half-life crystallization times 42 times higher than PCL homopolymer and two-dimensional crystallization growth. Copolymers’ growing rate values are 51 times higher than PCL values according to Hoffman-Weeks equation. These results suggest that interaction of grafted chains could hinder the rearrangement of PCL by reducing their final crystallization capacity.Fil: Ninago, Mario Daniel. Universidad Nacional de Cuyo. Facultad de Ciencias Aplicadas a la Industria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Redondo, Franco Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: De Freites, Augusto G. O.. Universidade Federal de Santa Maria; BrasilFil: Giacomelli, Cristiano. Universidade Federal do Pampa; BrasilFil: Ciolino, Andrés Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur; ArgentinaFil: Villar, Marcelo Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur; Argentin
Effects of enhancing soil organic carbon sequestration in the topsoil by fertilization on crop productivity and stability: Evidence from long-term experiments with wheat-maize cropping systems in China
Although organic carbon sequestration in agricultural soils has been recommended as a 'win-win strategy' for mitigating climate change and ensuring food security, great uncertainty still remains in identifying the relationships between soil organic carbon (SOC) sequestration and crop productivity. Using data from 17 long-term experiments in China we determined the effects of fertilization strategies on SOC stocks at 0-20 cm depth in the North, North East, North West and South. The impacts of changes in topsoil SOC stocks on the yield and yield stability of winter wheat (Triticum aestivum L.) and maize (Zea mays L.) were determined. Results showed that application of inorganic fertilizers (NPK) plus animal manure over 20-30 years significantly increased SOC stocks to 20-cmdepth by 32-87% whilst NPK plus wheat/maize straw application increased it by 26-38% compared to controls. The efficiency of SOC sequestration differed between regions with 7.4-13.1% of annual C input into the topsoil being retained as SOC over the study periods. In the northern regions, application of manure had little additional effect on yield compared to NPK over a wide range of topsoil SOC stocks (18->50 Mg C ha(-1)). In the South, average yield from manure applied treatments was 2.5 times greater than that from NPK treatments. Moreover, the yield with NPK plus manure increased until SOC stocks (20-cmdepth) increased to similar to 35Mg C ha(-1). In the northern regions, yield stability was not increased by application of NPK plus manure compared to NPK, whereas in the South there was a significant improvement. We conclude that manure application and straw incorporation could potentially lead to SOC sequestration in topsoil in China, but beneficial effects of this increase in SOC stocks to 20-cm depth on crop yield and yield stability may only be achieved in the South. (C) 2016 Elsevier B.V. All rights reserved