José Moncada-Jiménez

Evaluation of pre-game hydration status, heat stress, and fluid balance during professional soccer competition in the heat

Abstract In this study, we assessed initial hydration status (stadium arrival urine specific gravity), fluid balance (pre- and post-game nude body weight, fluid intake, urine collection), and core temperature changes (pre-game, half-time, post-game) during a professional soccer game. We monitored 17 male players (including goalkeepers) between arrival at the stadium and the end of the game (3 h), playing at 34.9°C and 35.4% relative humidity, for an average wet bulb globe temperature (WBGT) heat stress index of 31.9°C. Data are reported as mean±standard deviation (range). Initial urine specific gravity was 1.018±0.008 (1.003–1.036); seven players showed urine specific gravity ≥ 1.020. Over the 3 h, body mass loss was 2.58±0.88 kg (1.08–4.17 kg), a dehydration of 3.38±1.11% body mass (1.68–5.34% body mass). Sweat loss was 4448±1216 ml (2950–6224 ml) versus a fluid intake of 1948±954 ml (655–4288 ml). Despite methodological problems with many players, core temperatures ≥ 39.0°C were registered in four players by half-time, and in nine players by the end of the game. Many of these players incurred significant dehydration during the game, compounded by initial hypohydration; thermoregulation may have been impaired to an extent we were unable to measure accurately. We suggest some new recommendations for soccer players training and competing in the heat to help them avoid substantial dehydration.This study evaluated initial hydration status (stadium arrival urine specific gravity), fluid balance (preand post-game nude body weight, fluid intake, urine collection), and core temperature changes (pre-game, half-time, post-game) during a professional soccer game. We monitored 17 male players (goalies included) between stadium arrival and game end (3h), playing at 34.9°C and 35.4% relative humidity, for an average Wet Bulb Globe Temperature (WBGT) heat stress index of 31.9°C. Data are mean ± SD (range). Initial urine specific gravity (USG) was 1.018 ± 0.008 (1.003-1.036); seven players showed USG ≥ 1.020. Over the three hours, body mass (BM) loss was 2.58 ± 0.88kg (1.08-4.17kg), a dehydration of 3.38 ± 1.11%BM (1.68-5.34%BM). Sweat loss was 4448 ± 1216mL (29506224mL), vs. fluid intake of 1948 ± 954mL (655-4288mL). Despite methodological problems with many players, core temperatures greater than or equal to 39.0°C were registered in four players by halftime, and in nine by game’s end. Many of these players incurred significant dehydration during the game, compounded by initial hypohydration; thermoregulation may have been impaired to an extent we were unable to measure accurately. We suggest some new recommendations for soccer players training and competing in the heat to help them avoid substantial dehydration.

Predictive validity of the body adiposity index in costa rican students

To verify the validity of the body adiposity index (BAI) in a sample of Costa Rican students.

Acute Consumption of an Energy Drink Does Not Improve Physical Performance of Female Volleyball Players.

To determine the acute effect of an energy drink (ED) on physical performance of professional female volleyball players. 19 females (age= 22.3 ± 4.9 yr.; height= 171.8 ± 9.4 cm; weight= 65.2 ± 10.1 kg) participated in a randomized, crossover, double-blind study to measure grip strength, vertical jump and anaerobic power in 3 different sessions (ED, placebo [PL] or no beverage [CTL]). For each session, participants arrived in a fasted state, consumed a standardized breakfast meal, and 1 hr later completed the 3 baseline performance tests without having ingested the beverage. After completing the premeasurements, the athletes drank 6 ml/kg of body weight of the ED or PL and in the CTL condition no beverage was consumed. Posttest measurements were taken 30 min after the ingestion of liquids. A 3 × 2 repeated-measures ANOVA revealed no significant within-session and measurement time interactions for each performance test. Regardless of the measurement time, right hand grip strength was significantly higher in the ED condition (34.6 ± 0.9 kg) compared with PL (33.4 ± 1.1 kg) and CTL (33.6 ± 1.0 kg) (p < 0.05). Regardless of the beverage ingested, averaged right hand grip strength, taking into account all 3 testing conditions, increased from pre to posttesting (Pre = 33.8 ± 0.9 kg vs. Post = 33.9 ± 1.0 kg; p = 0.029), as did the averaged fatigue index, obtained from the anaerobic power test (Pre = 65.9± 2.2% vs. Post = 68.7± 2.0%; p= 0.049). The acute ingestion of an ED did not improve physical performance of professional Costa Rican female volleyball players.

Paraoxonase responses to exercise and niacin therapy in men with metabolic syndrome

Abstract Our purpose was to characterize changes in paraoxonase 1 (PON1) activity and concentration after single aerobic exercise sessions conducted before and after 6 weeks of niacin therapy in men with metabolic syndrome (MetS). Twelve men with MetS expended 500 kcal by walking at 65% of VO2max before and after a 6-week regimen of niacin. Niacin doses were titrated by 500 mg/week from 500 to 1500 mg/day and maintained at 1500 mg/day for the last 4 weeks. Fasting blood samples were collected before and 24 hours after each exercise session and analyzed for PON1 activity, PON1 concentration, myeloperoxidase (MPO), apolipoprotein A1, oxidized low-density lipoprotein (oLDL), lipoprotein particle sizes and concentrations. PON1 activity, PON1 concentration, MPO, and oLDL were unaltered following the independent effects of exercise and niacin (P > 0.05 for all). High-density lipoprotein particle size decreased by 3% (P = 0.040) and concentrations of small very low-density lipoprotein increased (P = 0.016) following exercise. PON1 activity increased 6.1% (P = 0.037) and PON1 concentrations increased 11.3% (P = 0.015) with the combination of exercise and niacin. Exercise and niacin works synergistically to increase PON1 activity and concentration with little or no changes in lipoproteins or markers of lipid oxidation.

Who Is Likely to Benefit From Phase II Cardiac Rehabilitation

PURPOSE To ascertain which patients are most likely to benefit from a phase II cardiac rehabilitation (CR) program. METHODS A retrospective chart review was conducted on 425 patients who completed a 6-minute walk test (6MWT), body weight (BW), and the Medical Outcomes Short Form Health Survey physical (PCS) and mental (MCS) component scores before and after CR. These variables were compared between patients who attended 24 or less and 25 or more sessions and between tertiles on the basis of initial 6MWT and the relative change in 6MWT. RESULTS The entire cohort of patients improved their 6MWT 20.1 ± 16.3% with CR (P < .001). On average, patients experienced a modest reduction in BW (P = .03) and had higher PCS and MCS scores (P < .001 for both) after CR. The improvement in 6MWT was inversely related to initial walk distance (r = −0.465, P < .001). Patients in the lowest initial 6MWT tertile exhibited greater improvement in the 6MWT than those in the highest tertile (28 ± 20 vs 13 ± 10%, P < .001). Patients who attended 25 or more sessions demonstrated greater 6MWT (20 ± 18 vs 18 ± 14%, P = .012) and reductions in BW (−1.3 ± 2.8 vs −0.5 ± 2.5 kg, P = .003) than those attending 24 or fewer sessions. Patients exhibiting greater than 23% improvement in 6MWT lost more BW (−1.4 ± 2.9 vs −0.6 ± 2.5 kg, P = .006) and exhibited greater PCS (10.2 ± 9.8 vs 6.3 ± 9.4, P = .004) than those exhibiting <12% improvement. CONCLUSIONS Most patients benefit physically and mentally from CR. Patients with lower initial functional ability and who attend 25 or more sessions enjoy the greatest improvements in walking ability and perception of physical health and function.

Acute Effects of Exercise on Blood Pressure: A Meta-Analytic Investigation

Hypertension affects 25% of the worlds population and is considered a risk factor for cardiovascular disorders and other diseases. The aim of this study was to examine the evidence regarding the acute effect of exercise on blood pressure (BP) using meta-analytic measures. Sixty-five studies were compared using effect sizes (ES), and heterogeneity and Z tests to determine whether the ES were different from zero. The mean corrected global ES for exercise conditions were -0.56 (-4.80 mmHg) for systolic BP (sBP) and -0.44 (-3.19 mmHg) for diastolic BP (dBP; z ≠ 0 for all; p < 0.05). The reduction in BP was significant regardless of the participants initial BP level, gender, physical activity level, antihypertensive drug intake, type of BP measurement, time of day in which the BP was measured, type of exercise performed, and exercise training program (p < 0.05 for all). ANOVA tests revealed that BP reductions were greater if participants were males, not receiving antihypertensive medication, physically active, and if the exercise performed was jogging. A significant inverse correlation was found between age and BP ES, body mass index (BMI) and sBP ES, duration of the exercises session and sBP ES, and between the number of sets performed in the resistance exercise program and sBP ES (p < 0.05). Regardless of the characteristics of the participants and exercise, there was a reduction in BP in the hours following an exercise session. However, the hypotensive effect was greater when the exercise was performed as a preventive strategy in those physically active and without antihypertensive medication.

Efecto del ejercicio físico de hidrogimnasia sobre la concentración sérica de inmunoglobulina A en mujeres adultas mayores

BACKGROUND Decreases in function of the immune system with age contribute to the increase the risk of infectious diseases especially the upper respiratory tract. On the other hand, physical activity has been widely recommended for health. However, more studies are needed to support the benefit effect of exercise on immune system in elderly. AIM To evaluate the effect of the hydrogymnastics on the serum level of immunoglobulin A (IgA) in elderly women. METHODS Twenty-six participants were randomly assigned to an experimental (n: 16) or a control group (n: 10). IgA concentrations were determined by nephelometry (BN2 Analyzer, Dade Behring). The hydrogymnastics training protocol was performed 5 times a week during 12 weeks. The intensity of the aerobic exercise was 50-60% of the maximum heart rate monitored by telemetry (Polar-FT7). RESULTS No significant differences (p: 0.797) resulted by ANOVA on serum IgA levels; the percentage of change in experimental group was Δ% = -6.7 mg/dL compared to the control group, Δ%= -7.4 mg/dL. CONCLUSION After three months of hydrogymnastics the IgA level did not show significant change on elderly women; However, positive improvement in percentage of change Δ% was found.

Body fat predicts forced vital capacity in college males

The study was designed to determine how body fat percentage (BF%), body fat distribution (BFD), and abdominal muscular endurance (AME) relate to pul-monary function (PF) as measured by the forced vital capacity (FVC), the forced expiratory volume in 1 s (FEV1), the FEV1/FVC ratio, and the maximal inspiratory pressure (MIP) among college (M= 22.82,SD = 2.45 yr) males (N= 60). Multiple regression analyses were calculated. A ceiling effect for AME was found; hence, AME was not used as a predictor variable in the multiple regression analyses. The distribution of MIP values was leptokurtic; therefore, MIP was excluded from the analysis. Body weight (p =.00) and body height (p=.03) were positively related to FVC. BF% was inversely (p=.05) related to FVC but was unrelated to FEV1 or FEV1/FVC. The predictor variable BFD was unrelated to FVC, FEV 1, or FEV 1 /FVC. In conclusion, increased proportions of fat were inversely related to FVC in college males.

Acute hepatic response to diet modification and exercise-induced endotoxemia during a laboratory-based duathlon.

The purpose of the study was to compare the acute hepatic response to diet modification and exercise-induced endotoxemia, and to determine if associations exist between liver damage markers, body core temperature, and IL-6 responses to a laboratory-based duathlon. Eleven moderately-trained healthy males followed a low-carbohydrate (CHO) and a high CHO diet to change their glycogen stores two-days before completing a duathlon. Blood samples were obtained at rest, immediately after and 1and 2-h following the duathlon for determination of endotoxin-lipopolysaccharide binding protein (LPS-LBP) complex, IL-6, and liver integrity markers AST, ALT, and AST/ALT ratio. Hydration status and body core temperature were assessed at rest, during, and after the duathlon. Athletes were more dehydrated and had higher AST/ALT ratios in the lowcompared to the high-CHO diet trial regardless of the measurement time (p<0.05). IL-6 increased from resting to immediately after, 1and 2-h following duathlon regardless of the diet (p<0.05). A higher LPS-LBP complex concentration was observed from rest to immediately after the duathlon. No significant correlations were found between LPS-LBP complex levels and body core temperature. In conclusion, athletes on a low-CHO diet showed higher hepatic structural damage and finished more dehydrated compared to athletes on a high-CHO diet. Body core temperature and LPS-LBP complex levels were unrelated beyond the increase in body core temperature explained by exercise. No significant associations were found between body core temperature, IL-6 and LPS-LBP complex concentrations.

Health-Related Quality of Life of Older Adults in Costa Rica as Measured by the Short-Form-36 Health Survey

Objective: To test the validity of a common measure of health-related quality of life (Short-Form-36 [SF-36]) in cognitively healthy older adults living in rural and urban Costa Rica. Method: Confirmatory factor analysis was applied to SF-36 data collected in 250 older adults from San Jose and Guanacaste, Costa Rica. Results: The best fitting model for the SF-36 was an eight first-order factor structure. A high correlation between the Mental Component Summary and Physical Component Summary scores was found. Region differences indicated that rural dwellers perceive a poorer health-related quality of life compared with the urban group. Discussion: Costa Rican older adults perceived health as a unidimensional construct. Age and urbanity of older adult Costa Ricans should be appreciated when trying to measure self-reported physical and mental health. Cultural context of the individuals should be considered when studying health-related quality of life.