Answer:
Initially; This step; During
Step-by-step explanation:
To train for a half marathon, a runner needs to learn the running basics. Initially, the new runner needs to learn good running technique to help prevent injury. Another essential aspect is building up endurance. This step requires gradual increases in running distances, which helps prevent burnout. During the training period, new runners must also change their lifestyles. They need to follow a strict eating and sleeping schedule to maintain their health as they train.