The Boston Marathon course is famous for its hills. From the start in Hopkinton to the finish on Boylston Street in Boston, the runner must navigate a challenging landscape that tests every muscle in the legs.

Miles 0-5: A gentle downhill start, deceiving in its ease. Most runners go out too fast here, not realizing they’re saving their strength for later suffering.

Miles 5-16: Rolling hills in suburban Boston. Nothing too dramatic, but the constant up-and-down drains energy from the legs. By mile 16, many runners are beginning to feel the effects of the Newton Hills to come.

Miles 16-21: The Newton Hills. Four hills in succession: Walnut Hill, Brae Side, Heartbreak Hill, and then a final descent. Heartbreak Hill is the most famous, but all four are challenging.

Miles 21-26.2: Downhill to the finish. A welcome change from the Newton Hills, but the eccentric loading on the quads makes these miles challenging for tired legs.