Which keywords and phrases indicate that the excerpt is taken from a sequence essay? 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.