Analysis and comparison of intensity in specific soccer training sessions

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