The purpose of this study was to assess the intensity of official Futsal matches, expressed in different ways. Fourteen male professional Futsal players from a First Division Brazilian team volunteered to participate in this study. Maximal oxygen uptake (VO(2)max) and the heart hate (HR) and oxygen uptake (VO(2)) correlation were determined for each player. The match intensity was estimated from the players' average HR measured during 13 National Futsal League matches. The HR measurements were obtained while the players were in the court but the values recorded while the players were sitting on the bench were not considered. In addition, these HR values were used to estimate the intensity of the effort expressed as a percentage of the maximal HR (% HRmax), percentage of VO(2)max (% VO(2)max), kilocalories per minute (kcal·min(-1)), and total caloric expenditure. The mean intensity of the matches was 86.4 ± 3.8% HRmax, 79.2 ± 9.0% VO(2)max, 18.0 ± 2.2 kcal·min(-1), and 313 ± 9.3 kcal. It was concluded that official Futsal matches have high intensity when expressed in the different ways used in this study. The information provided by this research can be used for planning the athletes' workouts, diets, and resting periods.

•kg-1 •min-1) pertencentes a um clube da primeira divisão do futebol brasileiro. A freqüência cardíaca (FC) dos atletas foi medida usando-se um conjunto de cardiofrequencímetros, durante jogos de competições oficiais, sendo 14 jogos da categoria juvenil (menos de 17 anos) e 8 jogos da categoria júnior (menos de 21 anos). A freqüência cardíaca máxima (FC máx) de cada atleta foi considerada como o maior valor de FC observado entre dois testes máximos (corrida de 1000m e 2400m) utilizados para a determinação da mesma. Nos casos em que foram observados valores superiores da FC durante as situações de jogo em relação aos testes, esta foi considerada como a FC máx individual. Os resultados foram analisados usando-se o teste t-Student com nível de significância adotado de p<0,05. Resultados: Foi observada diferença (p<0,01) da FC média e do percentual da freqüência cardíaca máxima (%FC máx) entre o primeiro tempo (170 ± 8 bpm e 85,2 ± 4,5%FC máx) e o segundo tempo (166 ± 10 bpm e 82,7 ± 4,6%FC máx). Os resultados traduzem uma menor intensidade do esforço no segundo tempo de jogo, comparativamente com o primeiro tempo.

This study compared the exercise intensity of four specific soccer training sessions (friendly and training match, tactical and technical workouts). Ten professional soccer players (24.2 ± 3.7 years, 177.9 ± 7.3 cm, 63.2 ± 4.6 mLO2•kg-1•min-l) were recruited. A treadmill progressive interval test was performed to determine the players' VO2max, maximal heart rate (HRmax), HR-VO2 curve, and the heart rate corresponding to blood lactate concentrations of 2 and 4 mmol/L. The heart rate during the training sessions was used to estimate the exercise intensity and to classify them into intensity zones (low-intensity: <2 mmol/L; moderate-intensity: between 2 and 4 mmol/L; high-intensity: >4 mmol/L). Exercise intensities were different among training sessions (friendly match: 86.0 ± 5.1% HRmax; training match: 81.2 ± 4.1% HRmax; tactical workout: 70.4 ± 5.3% HRmax; technical workout: 62.1 ± 3.6% HRmax). The friendly match presented the highest percentage of time performed in the high-intensity zone.