Billy told his boss, gwen, that he is going to start training for the upcoming marathon to be healthier and to have more energy for work. when gwen asked him about his running history, billy said, i really have never run before and don't exercise much. i just know i need to do something. gwen told billy, you should start slowly, maybe setting smaller, realistic exercise goals that are achievable. gwen is billy with an achievable goal, a type of