Each year, thousands of people lace up their athletic shoes and grab their water bottles in order to run the 26.2 miles that make up a marathon. Even for experienced athletes, enduring that much cardio exercise is strenuous on the body. For beginning athletes, a marathon isn’t something you can just do on a whim. It takes training, practice and a specially designed workout regimen in order to complete the entire event. For this reason, many people choose to hire personal trainers to help them get into marathon shape. Here are three ways a personal trainer can help you reach the finish line.