The first two bars are a gallop rhythm, and the last two bars are a reverse gallop. Usually, these rhythm are done with 16th and 8th notes, but for this exercise, we're using 8th and quarter notes.
The count for this is 1-2n3-4n|1-2n3-4n|1n2-3n4-|1n2-3n4-
Here is the Guitar Pro 6 tab for this lesson:
Available Instruction Courses