Table 1. Description of the HIIT training program. Week Session Singles-HIIT (on-court, no serving) Sets × rallies × time per rally Doubles-HIIT (on-court, no serving) Sets × rallies × time per rally Running-HIIT (regHIIT, shuttle running at %VIFT) Bouts× time per bout Total effective work time per player (min) 1 1 2 sets × (6–8 rallies × 30–40 s, 30 s rest between rallies); 3 min rest between sets 2 sets × (6–8 rallies × 30–40 s, 30 s rest between rallies); 3 min rest between sets; players alternate actions within each rally 12 bouts × 30–40 s @ 85% VIFT, 30 s rest between bouts 8 1 2 2 sets × (8–10 rallies × 30–40 s, 30 s rest); 3 min rest between sets 2 sets × (8–10 rallies × 30–40 s, 30 s rest); 3 min rest; shared workload between partners 16 bouts × 30–40 s @ 95% VIFT, 30 s rest 10-11 2 3 2 sets × (6–8 rallies × 30–40 s, 30 s rest); 3 min rest between sets 2 sets × (6–8 rallies × 30–40 s, 30 s rest); 3 min rest; alternate strokes 12 bouts × 30–40 s @ 85% VIFT, 30 s rest 8 2 4 2 sets × (8–10 rallies × 30–40 s, 30 s rest); 3 min rest 2 sets × (8–10 rallies × 30–40 s, 30 s rest); 3 min rest; alternate strokes 16 bouts × 30–40 s @ 95% VIFT, 30 s rest 10-11 3 5 2 sets × (8–10 rallies × 30–40 s, 30 s rest); 3 min rest 2 sets × (8–10 rallies × 30–40 s, 30 s rest); 3 min rest; shared workload 16 bouts × 30–40 s @ 85% VIFT, 30 s rest 10-11 3 6 2 sets × (10–12 rallies × 30–40 s, 30 s rest); 3 min rest 2 sets × (10–12 rallies × 30–40 s, 30 s rest); 3 min rest; shared workload 20 bouts × 30–40 s @ 95% VIFT, 30 s rest 12-13 4 7 2 sets × (8–10 rallies × 30–40 s, 30 s rest); 3 min rest 2 sets × (8–10 rallies × 30–40 s, 30 s rest); 3 min rest; shared workload 16 bouts × 30–40 s @ 85% VIFT, 30 s rest 10-11 4 8 2 sets × (10–12 rallies × 30–40 s, 30 s rest); 3 min rest 2 sets × (10–12 rallies × 30–40 s, 30 s rest); 3 min rest; shared workload 20 bouts × 30–40 s @ 95% VIFT, 30 s rest 12-13 5 9 2 sets × (10–12 rallies × 30–40 s, 30 s rest); 3 min rest 2 sets × (10–12 rallies × 30–40 s, 30 s rest); 3 min rest; shared workload 20 bouts × 30–40 s @ 85% VIFT, 30 s rest 12-13 5 10 2 sets × (12–14 rallies × 30–40 s, 30 s rest); 3 min rest 2 sets × (12–14 rallies × 30–40 s, 30 s rest); 3 min rest; shared workload 24 bouts × 30–40 s @ 95% VIFT, 30 s rest 14-16 6 11 2 sets × (10–12 rallies × 30–40 s, 30 s rest); 3 min rest 2 sets × (10–12 rallies × 30–40 s, 30 s rest); 3 min rest; shared workload 20 bouts × 30–40 s @ 85% VIFT, 30 s rest 12-13 6 12 2 sets × (12–14 rallies × 30–40 s, 30 s rest); 3 min rest 2 sets × (12–14 rallies × 30–40 s, 30 s rest); 3 min rest; shared workload 24 bouts × 30–40 s @ 95% VIFT, 30 s rest 14-16 HIIT: high-intensity interval training; regHIIT: running-based HIIT; VIFT: final velocity at 30-15 intermittent fitness test. Total effective work time per player is the workout time excluding rest periods.