Using Metabolomics to Differentiate Player Positions in Elite Male Basketball Games: A Pilot Study

Purpose: The current study compared metabolic profiles and movement patterns between different player positions and explored relationships between indicators of internal and external loads during elite male basketball games.Methods: Five main players from 14 basketball teams (n = 70) were selected as subjects and defined as backcourt (positions 1–3) or frontcourt (positions 4–5) players. Video-based time motion analysis (VBTMA) was performed based on players’ individual maximal speeds. Movements were classified into high and low intensity running with and without ball, high and low intensity shuffling, static effort and jumps. Saliva samples were collected before and after 40-min basketball games with metabolomics data being analyzed by multivariate statistics. Independent t-tests were used to compare VBTMA.Results: Frequency, duration, and distance of high and low intensity running and -shuffling were higher in backcourt players, whereas static effort duration and frequency as well as jump frequency were higher in frontcourt players (all p ≤ 0.05). The levels of taurine, succinic acid, citric acid, pyruvate, glycerol, acetoacetic acid, acetone, and hypoxanthine were higher in backcourt players, while lactate, alanine, 3-methylhistidine were higher and methionine was lower in frontcourt players (all p < 0.05). High intensity running with ball was significantly associated by acetylecholine, hopoxanthine, histidine, lactic acid and leucine in backcourt players (p < 0.05).Conclusion: We demonstrate different metabolic profiles of backcourt and frontcourt players during elite male basketball games; while aerobic metabolic changes are more present in backcourt players, frontcourt players showed lager changes in anaerobic metabolic pathways due to more static movements.

AVALIAÇÃO DA CARGA DE TRABALHO FÍSICO E DO RISCO DE LER/DORT EM TRABALHADORES DA COLHEITA EM ÁREA COM MADEIRA DANIFICADA PELO VENTO

Este estudo realizou uma avaliação ergonômica dos trabalhadores da colheita de madeira danificada pelo vento, no Estado de Minas Gerais, de forma a determinar os riscos ergonômicos a que os trabalhadores estavam expostos durante o desenvolvimento dessas atividades. Foi avaliado, para cada uma das atividades desenvolvidas, a carga de trabalho físico por meio da frequência cardíaca e o risco de LER/DORT, através da avaliação simplificada do fator biomecânico no risco para distúrbios músculo esquelético de membros superiores relacionados ao trabalho. Os resultados evidenciaram que o ambiente de trabalho estudado proporcionava diferentes riscos ergonômicos aos trabalhadores. Na avaliação da carga de trabalho físico, todas as atividades avaliadas encontraram-se acima dos limites de carga cardiovascular recomendados, o que expõe os trabalhadores ao risco de desenvolvimento de doenças ocupacionais, sendo necessária a reorganização do trabalho. A análise dos riscos de surgimento de LER/DORT indicou, da mesma forma, a necessidade de reorganização do trabalho, pois a execução das atividades oferecia risco alto a altíssimo de lesões ao trabalhador, principalmente devido à alta frequência de movimentos repetitivos associados ao esforço estático e ao manuseio de cargas pesadas, fatores presentes na rotina da colheita de madeira danificada por ventos.Palavra-chave: manejo florestal, risco ergonômico, saúde do trabalhador. WIND-DAMAGED WOOD HARVESTING: PHYSICAL WORK LOAD AND RSI/WRMD RISK TO THE WORKERS ABSTRACT:This study carried out an ergonomic evaluation of the workers of the harvest of wood damaged by the wind, in the State of Minas Gerais, in order to determine the ergonomic risks to which workers were exposed during the development of these activities. The physical workload by means of heart rate and the risk of RSI/WRMD by means of the simplified evaluation of the biomechanical factor in the risk for work-related upper limb musculoskeletal disorders were evaluated for each of the activities developed. The results showed that the work environment provided different ergonomic risks to workers. In the evaluation of the physical workload, all the activities evaluated were above the recommended limits of cardiovascular load, which exposes the workers to the risk of developing occupational diseases, being necessary the reorganization of the work. The analysis of the risks of the emergence of RSI/WRMD also indicated the need to reorganize the work, since the execution of the activities offered a high risk of injury to the worker, mainly due to the high frequency of repetitive movements associated with the static effort And to the handling of heavy loads, factors present in the routine of harvesting of wood damaged by winds.Keywords: forest management, ergonomic risk, worker’s health. DOI:

Interactions between fatiguing and nonfatiguing isometric contractions

Isometric contractions of the handgrip muscles were exerted by eight male subjects (age range 19-24 yr) to determine the relationship between fatiguing and nonfatiguing isometric contractions. In a first series of experiments, subjects exerted fatiguing isometric contractions at tensions of 25, 40, or 70% of the maximum strength of the subjects (MVC) following a contraction at a nonfatiguing tension of 5 or 10% MVC for 3, 7, or 20 min. In a second series of experiments, subjects exerted pairs of fatiguing isometric contractions at the same tensions; however, during the 3-, 7-, or 20-min interval between the contractions the subjects either rested or exerted a contraction at 5 or 10% MVC. Nonfatiguing isometric contractions exerted prior to fatiguing contractions had little influence on the endurance for the fatiguing static effort. In contrast, when contractions at nonfatiguing tensions were exerted in the recovery interval following an isometric contraction at a fatiguing tension, the recovery of endurance was dramatically reduced.

Respiratory Responses to Simultaneous Static and Rhythmic Exercises in Humans

1. Six male subjects performed simultaneous static (hand-grip) and rhythmic (bicycle ergometer) exercises while their respiratory responses were measured. 2. Oxygen consumption increased with the intensity of rhythmic work load, with a modest additional oxygen consumption accompanying the addition of static effort during the rhythmic exercise. 3. Minute ventilation (V̇E) increased directly with rhythmic exercise, but increased disproportionately to the metabolic need when static effort was added. The mean increment of V̇E elicited by the static exercise influence was nearly constant at 20 1/min, regardless of the rhythmic load present. 4. Possible reflex mechanisms which result in disruption of the normally well-matched ventilation and metabolic oxygen demands whenever static effort is present are discussed.