José Soares

Physical and Physiological Demands of Elite Team Handball

Abstract Póvoas, SCA, Seabra, AFT, Ascensão, AAMR, Magalhães, J, Soares, JMC, and Rebelo, ANC. Physical and physiological demands of elite team handball. J Strength Cond Res 26(12): 3365–3375, 2012—This study aimed to analyze elite team handball physical and physiological demands during match play. Time-motion (N = 30) and heart rate (HR; N = 60) analyses were performed throughout 10 official matches. The defined locomotor categories were standing still, walking, jogging, fast running, sprinting, backwards movement, sideways medium-intensity movement, and sideways high-intensity movement, and playing actions studied were jumps, shots, stops when preceded by high-intensity activities, changes of direction and one-on-one situations. During matches, the mean distances covered were 4,370 ± 702.0 m. Around 80% of the total time was spent standing still (43.0 ± 9.27%) and walking (35.0 ± 6.94%) and only 0.4 ± 0.31% with sprinting. The most frequent high-intensity actions were stops, changes of direction, and one-on-one situations. Effective mean HR was 157 ± 18.0 b·min−1 (82 ± 9.3% of HRmax), and total HR was 139 ± 31.9 b·min−1 (72 ± 16.7% of HRmax). The HR, time spent in high-intensity activities, frequency of stops, changes of direction, one-on-one situations, and most intense periods of the game were higher during the first half than during the second half (p ⩽ 0.05). The opposite was observed for the number of time outs and the time between each change of activity (p = 0.00). Handball is an intermittent exercise that primarily uses aerobic metabolism, interspersed by high-intensity actions that greatly tax anaerobic metabolism. Additionally, exercise intensity decreases from the first to the second half of the match, suggesting that neuromuscular fatigue may occur during the game. The training of elite handball players should comprise exercises targeting the ability to perform specific high-intensity actions throughout the game and to rapidly recover during the less intense periods.

Dietary strategies to recover from exercise-induced muscle damage

Abstract Exhaustive or unaccustomed intense exercise can cause exercise-induced muscle damage (EIMD) and its undesirable consequences may decrease the ability to exercise and to adhere to a training programme. This review briefly summarises the muscle damage process, focusing predominantly on oxidative stress and inflammation as contributing factors, and describes how nutrition may be positively used to recover from EIMD. The combined intake of carbohydrates and proteins and the use of antioxidants and/or anti-inflammatory nutrients within physiological ranges are interventions that may assist the recovery process. Although the works studying food instead of nutritional supplements are very scarce, their results seem to indicate that food might be a favourable option as a recovery strategy. To date, the only tested foods were milk, cherries, blueberries and pomegranate with promising results. Other potential solutions are foods rich in protein, carbohydrates, antioxidants and/or anti-inflammatory nutrients.

Hydrotalcite Materials for Carbon Dioxide Adsorption at High Temperatures: Characterization and Diffusivity Measurements

Abstract Hydrotalcites are receiving considerable attention as adsorbents, catalysts, and catalyst precursors. However, the use of hydrotalcites as an adsorbent material for carbon dioxide has only been considered recently. In this work, three commercial hydrotalcites, Puralox MG30, MG50, and MG70, were used for the removal of CO2 at temperatures in the range 423–623 K. The adsorbent materials were characterized by use of scanning electron microscopy/energy dispersive x‐ray, mercury porosimetry, and N2 adsorption at 77 K, which indicated the presence of micropores. The HK plot suggested pore‐width values around 0.55 nm. The BET surface areas were 199, 154, and 144 m2/g for MG30, MG50, and MG70, respectively. The micropore areas calculated by the DR method were 206, 161, and 146 m2/g. The diffusivity of CO2 onto hydrotalcite adsorbents was measured by the zero length column method. Kinetic studies indicated that the controlling mechanism for mass transfer inside the extrudate was micropore diffusion. The reciprocal of the time constants for micropore diffusion (D c/l 2) were 8.5 × 10−3–15.3 × 10−3 s−1 for MG30, 8.0 × 10−3–10.4 × 10−3 s−1 for MG50, and 6.8 × 10−3–11.3 × 10−3 s−1 for MG70, in the temperature range 423–623 K.

Effect of off-road competitive motocross race on plasma oxidative stress and damage markers

Aim: To analyse the effect of an off-road motocross heat on plasma levels of oxidative stress and damage, blood leucocyte counts and urine catecholamine concentration. Methods: Plasma contents of total, reduced and oxidised (GSSG) glutathione, %GSSG, malondialdehyde (MDA), protein carbonyl and sulphydryl groups, total antioxidant status (TAS), uric acid, and blood neutrophil and lymphocyte counts were evaluated in 10 male top-level riders before, immediately after (0 h) and 1 h after a simulated competitive motocross race. 24-h urine adrenaline, noradrenaline and dopamine concentrations were also measured. Results: The motocross heat resulted in an increase in plasma oxidative stress and damage (p<0.05). This was shown by a significant increase in %GSSG, TAS, MDA and carbonyls, and by a decrease in sulphydryl groups after the race. There was a significant increase in both plasma uric acid and urine catecholamine concentration after the race (p<0.05). Blood neutrophil counts increased at 0 and 1 h after exercise (p<0.05). Lymphocyte count increased from baseline to 0 h, although it decreased from baseline and 0 to 1 h after exercise (p<0.05). Conclusion: The data reinforce the marked metabolic and hormonal demands imposed by motocross, resulting in a condition of enhanced plasma oxidative stress and damage.

Prevenção de lesões do ligamento cruzado anterior em futebolistas

Knee injury is the commonest severe injury presented by football players and the anterior cruciate ligament appears as one of the most frequently injured knee ligaments. Thus, prevention of anterior cruciate ligament injuries must be a priority in soccer practice, regardless of the athletes competitive level, age or sex. OBJECTIVES: the objective of this work is to analyze the importance of prevention of the anterior cruciate ligament injury in soccer players which can be incorporated in the training program. METHODOLOGY: the methodology used was a review of the literature. CONCLUSIONS: A program with three weekly sessions, composed by neuromuscular and proprioceptive training is proposed to prevent anterior cruciate ligament injuries in soccer players.

Nutritional supplements use in high-performance athletes is related with lower nutritional inadequacy from food

Background The use of nutritional supplements (NS) among athletes is widespread. However, little is known about the relationship between nutritional adequacy and NS usage. The aims of this study were to evaluate the NS usage and to compare the nutritional intake from food and prevalence of micronutrient inadequacy (PMI) between NS users and non-users. Methods Portuguese athletes from 13 sports completed an NS usage questionnaire and a semi-quantitative food-frequency questionnaire assessing information over the previous 12 months. The estimated average requirement cut-point method was used to calculate PMI. General linear models were used to compare nutritional intake and NS usage. Chi-squared tests and logistic regression were performed to study, respectively, relationships and associations between PMI and NS usage. Results From the 244 athletes (66% males, 13–37 years), 64% reported NS usage. After adjustment, NS users showed a higher intake from food (p < 0.05), for at least 1 gender, for energy, and for 7 of the 17 studied nutrients. The highest PMI were seen for vitamins D and E, calcium, folate, and magnesium. After adjustment, NS users, irrespective of gender, reported lower PMI for calcium (ORu2009=u20090.28, 95%CI: 0.12–0.65), and female users for magnesium (ORu2009=u20090.06, 95%CI: 0.00–0.98). Conclusion Athletes using NS reported a higher nutritional intake from food, and a lower PMI for several nutrients. Perhaps, those who were taking NS were probably the ones who would least benefit from it.

Nutritional supplement-usage associated characteristics of high-performing athletes

Purpose – The purpose of this paper is to analyse differences in sociodemographic and sporting characteristics, health-behaviours, and food intake of athletes using and not using nutritional supplements (NS). Design/methodology/approach – High-performance Portuguese athletes from 13 sports completed a NS usage questionnaire, assessing information on sociodemographic (sex, age, height, weight, athlete’s, and parental education level), health-related (smoking, daily time of sleeping, walking, and sitting), and sporting (type, number of international performances, weekly hours of training and weekly hours of gym) characteristics; and a semi-quantitative food-frequency questionnaire (86 items), regarding the previous 12 months. Findings – From the 241 athletes (66 per cent males, 13-37 years), 64 per cent reported NS use. Supplement usage was associated with age ue2f618 years (odds ratio (OR) 2.57, 95 per cent; confidence interval (CI) 1.17-5.65), performing individual sports (OR 5.45, 95 per cent; CI 2.49-11.93)...

Modeling of Adsorptive Filtration of a Leather Dye in a Fixed Bed Column

Abstract Activated carbons offer an efficient option for the removal of organic and inorganic contaminants from water. However, due to its high costs and difficulty in the regeneration, other low cost adsorbents have been used. In this work, the adsorption capacity of an adsorbent carbon with high iron oxides concentration was compared with that of a commercial activated carbon in the removal of a leather dye from an aqueous solution. The adsorbents were characterized using SEM/EDAX analysis and BET surface area. The capacity of adsorption of the adsorbents was evaluated through the static method at 25°C. The results showed that the color removal was due to the adsorption and precipitation of the dye on the surface of the solids. The adsorption equilibrium was described according to the linear model for the adsorbent carbon and the equilibrium constant was 0.02 L g−1. The equilibrium of adsorption on activated carbon exhibited a behavior typical of the Langmuir isotherm and the monolayer coverage was 24.33 mg g−1. A mathematical model was proposed to describe the dynamics of the color removal using a fixed bed considering that the color removal is due to the adsorption and the precipitation of the dye on the adsorbent.