I usually do stationary lunges in one spot. Once I switched to BGB program it calls for walking lunges.
While doing the walking lunges with a 30LB DB in each hand I can do around 6-7 each side (12-14 steps) but then my knee starts hurting with pain. Then I stop at or before 10 per side because it bothers me too much.
Why is this, and why would it only occur with walking lunges?