Most parents worry about this. Unfortunately, that's about how long the ACT and SAT tests are - without practice, the length of the test will definitely have a negative impact on your student's scores.
Lots of students struggle with this at first, but as we move through the classes, it becomes easier and easier for students to keep themselves on track. By Class 9, students can't believe how much easier it is to get through that block of 4 hours.
Plus, everything your student learns WILL help them to score better on their AP tests.