Polar precision performance sw 3

Heart Rate During Match Play. Heart rate was continuously measured with a sampling frequency of 5 seconds using a wireless team system (Polar Team Pro, Polar Precision Performance SW 3.0). The data were transferred to a personal laptop computer for analysis. Oxygen uptake during each game was estimated for each subject using the individual linear regression equation between HR and V _ O 2 obtained during the incremental treadmill test.
Activity Categories. Player movements were categorized as walking (0-6$km$h 21 ), jogging (6-12$km$h 21 ), cruise running (12-14$km$h 21 ), striding (14-18$km$h 21 ), highintensity running (18-20$km$h 21 ), and sprinting ($20$km$h 21 ). The speed thresholds for each category are similar to that reported by Cunniffe et al. (15) . Entry into a speed zone was recognized and recorded when a player maintained the relevant running velocity for $2 seconds. The frequency, duration, and distance covered in each speed zone were evaluated.

Maximal oxygen uptake (V _ O 2 max) was assessed on an automated treadmill (Woodway ELG55) using an incremental protocol. The protocol consisted of initial 4 3 4-minute stages. The initial treadmill velocity was set at 6.0$km$h 21 and was increased by 2.0$km$h 21 at the end of each stage. Treadmill velocity remained constant after the fourth stage, and the treadmill gradient was increased by 2% in the initial minute after the fourth stage and at 2-minute intervals thereafter, until volitional exhaustion. Expiratory gases were measured using a Sensormedics Vmax 229 Metabolic System (Sensormedics Corp., Yorba Linda, CA, USA), and the HR was continually measured using a wireless telemetry system (Polar Team Pro, Polar Precision Performance SW 3.0). V _ O 2 max was determined by averaging the 3 highest consecutive 20-second values. HRmax was considered the peak HR value measured during testing.