Estudio del metabolismo glucolítico en jugadores de baloncesto / Gycolytic metabolism in basketball players

Introducción: El baloncesto desde un punto de vista energético, es clasificado en un 15 % aeróbico (Fox y Mathews 1984). Dalmonte (1987), justifica la importancia del metabolismo láctico en competición en 20 %. Sin embargo hay pocos estudios que evalúen la intervención de la glucólisis durante los partidos, además, sólo algunos de ellos utilizan jugadores jóvenes. Objetivo: Valorar el metabolismo glucolítico, mediante análisis de lactato plasmático durante la competición y estudiar su cinética en función del tiempo y puesto. Metodología: A 15 jugadores internacionales junior se les realizó muestras antes, durante y después del partido. Resultados: Los datos de concentración de lactato (LA) final son cercanos a 4 mmol/ (3,92 mMol/l), siendo el más alto de (5,30 mMol/l). Existen diferencias significativas entre períodos de juego, así como del base con respecto a los demás. No hemos observado relación entre el tiempo de juego y la concentración de lactato. Conclusión: El uso del metabolismo glucolítico, tanto aeróbico como anaeróbico, parece tener una importancia, en el baloncesto de alto nivel, mayor de la que se pensaba hasta ahora. Su estudio puede aportar información práctica para ajustar cargas de entrenamiento, conocer la situación metabólica durante el juego y diseño de estrategias nutricionales y de recuperación de la fatiga

Introduction: The basketball from an energetic point of view, is classified in 15 % aerobic (Fox y Mathews 1984), Dalmonte (1987), reported the major role of lactic metabolism during competition in 20 %. But there is a few studies to evaluate glycolytic metabolism during competition, and a few scientific evidence with young players. Objetive: To measure the glycolitic metabolism during the matches by plasmatic lactate concentration and study differences between periods and positions. Metodology: 15 internacional male basketball players participated in this study. Blood lactate testing was performed pre, per and post competition. Results: Our data present (3.92 mMol/l), the highest value was (5.30 mMol/l). There are significant differences between periods and there is not relation between playing time and (LA). Conclusion: The glycolytic metabolism, aerobic and anaerobic can be useful information to know the metabolic responses during the games, nutritional strategies and fatigue/recovery relation

Upper body aerobic fitness comparison between two groups of competitive surfboard riders.

The aim of the present study was to evaluate and compare the upper-body aerobic fitness characteristics in 2 groups of competitive surfers with different performance levels. Thirteen male competitive surfers performed an incremental dry-land board paddling test to determine specific peak oxygen uptake (VO2peak), peak power output (Wpeak) and the exercise intensity (%VO2peak) that elicits a blood lactate concentration of 4 mmol x L(-1) (LT4). As a measure of surfing performance, surfers were ranked according to their competitive season performance (RANK) and divided into 2 groups based on their performance level; European top-level competitive surfers (ELS) (n = 7) and regional level competitive surfers (RLS) (n = 6). ELS reached significantly higher values than RLS for Wpeak (154.71 +/- 36.82 W vs. 117.70 +/- 27.14 W: P = 0.04) and LT4 (95.18 +/- 3.42 %VO2peak vs. 88.89 +/- 5.01 %VO2peak; P = 0.02) but not VO2peak (3.34 +/- 0.31 L x min(-1) vs. 3.40 +/- 0.37 L x min(-1); P = 0.77). Spearman-rank order correlation analysis revealed that RANK was inversely correlated with Wpeak (r = -0.65, P = 0.01) and LT4 (r = -0.58, P = 0.03). These findings identify that better surfers have higher upper body aerobic fitness scores.

Transient dissociation of bone metabolism induced by high performance exercise: a study in elite marathon runners.

Bone metabolism parameters were studied in 18 elite marathon runners (11 men and 7 women) who participated in the Marathon World Cup held at San Sebastian, Spain in 1993. Measurements were made before the race, immediately after the race, and 24 hours after the race. The most interesting finding was increased alkaline phosphatase (P < 0. 0001) and decreased tartrate-resistant acid phosphatase (P = 0.0035), which suggests that exercise produced uncoupling of the bone cell metabolism. Serum calcium corrected for proteins did not increase with exercise and at the end of the race there was a negative correlation between cortisol, which was significantly higher (P < 0. 0001), and corrected serum calcium (r = 0.53, P = 0.026) that was not present at baseline. Running time showed a significant negative correlation with baseline serum cortisol (r = -0.67, P = 0.0015) and a significant positive correlation with body mass index (r = 0.53, P = 0.0207). The increase in alkaline phosphatase persisted 24 hours after the race, which suggests that exercise produced an intense and sustained effect on osteogenic capacity.

Acid-base balance and electrolyte concentration in blood during graded exhausting exercise in non-trained subjects.

Venous acid-base balance and electrolyte concentration during step-graded and exhausting exercise with a two-minute steady-state has been studied in a group of non-trained young men. The results showed a significant decrease in pH, pCO2 and bicarbonate and a significant increase in lactate, potassium, inorganic phosphate and proteins during the exercise. The supervening acidosis had a large anion gap that was of proportion with the increase in lactate values. We suggest that the total sum of other anions such as proteins, phosphate, pyruvate, citrate, free fatty acids and aminoacids, as well as sodium-hydrogen exchange could account for this acidosis.