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 prevent injury. another essential aspect is building up endurance. [this step] requires gradual increases in running [distances], which 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.