"It feels like it weighs more than I do," Lynch said with a laugh.
High schools can look more like hiker conventions as students find it easier to carry their books in backpacks than to race back to their lockers between classes.
"It's like that at every school," said Natalie Friton, 18, a senior at North Hagerstown High School.
Book bags aren't big enough for many classes' books. The students carry their gear in backpacks made for weekend hiking.
Friton said some students may carry the backpacks as a fashion statement, but most wear them out of necessity.
"I know I've got a calculus book that weighs five pounds," Friton said.
It's not just the petite high-schoolers who get worn down by the weight of their books.
B.J. Mercer, 18, a junior at Jefferson High, is a husky, 205-pound football player who bench presses 260 pounds.
"All my classes are so separated, if I have to go to my locker, I'm tardy. It's easier to carry all my books in here," Mercer said.
"By the end of the day, the top of my shoulders are really sore," he said.
Andy Quezada, 16, a sophomore at Jefferson High, said he carries his books, papers, candy, pencils and "stuff like that" in his backpack to get him through the day.
"You've got to walk like this," Quezada said, bending over as if bowed down by the weight.
Charles Town chiropractor Dr. Henry Christie Jr. said he's not seen any "backpack syndrome" injuries among high-schoolers.
"Generally kids that age have strong backs and can carry the load," Christie said.
Christie said the minor aches and pains can add up to back problems later in life if they are not careful.
He recommended that students carry their backpacks with the straps over both shoulders rather than slung over one-shoulder.
Having the weight on one shoulder can cause an imbalance that could injure the back, Christie said.
"It's the same thing I recommend with women with heavy purses," Christie said.
"In junior high, everyone wore them on one shoulder. In high school it's on two shoulders," said Sarah Hoffman-Benadom, 17, a junior at Jefferson High.