Figure 1. Distribution of endurance training zones throughout the season (% of total training distance, in km). Z1: training zone 1 (long-distance continuous training or interval training [sets with 4 - 6 km], running paces between 3:45 - 3:10 min/km); Z2: training zone 2 (middle-distance interval training [sets with 1 - 3 km], running paces between 3:10 - 2:50 min/km); Z3: training zone 3 (short distance and sprint interval training [sets with 200 - 600 m], with running paces of sub 2:50 min/km up to maximum sprint).