Mile 17 might be one of the hardest on the course. Runners have just come down over 100 feet on route 16 and now you're climbing up and over 128. The crowds are a bit thinner and runners need to dig deep and focus before the Newton hills.
Mile 17 3:07 /2:24PM mile change +55 ft net change -375 ft
Mile 18 3:18 / 2:35PM mile change +30 ft net change -345ft
On my 21 mile training run I found mile 19 and 20 to be the easiest of them all. As strange as you might think after all the downhill pounding and then up hill just after the firehouse these are two relatively flat miles. I found my time was in the low 10's (after walking part of the first hill) and my energy renewed. At this point I had one of those few times where I thought I could run forever. Here as you pass through the center of Newton you'll pass city hall and dual John Kelly memorial where it's good luck if you rub their shoes (on your training runs)
Mile 19 3:29 /2:46PM mile change -15 ft net change -360 ft
Mile 20 3:41 / 2:57PM mile change +20 ft net change -340ft
Heartbreak hill has arrived. The most famous hill in all of racing. It's not the most steep but after everything we've just run through it takes a toll.
Mile 21 3:52 /3:08PM mile change +80 ft net change -260 ft
Mile 22 4:03 / 3:19PM mile change -80 ft net change -340ft
Here the course continues on Beacon Street through the heart of Brookline, to Coolidge Corner. Brookline's large population of apartment dwellers allows spectators to gather on balconies and rooftops to cheer runners through the homestretch.
Mile 23 4:14 /3:30PM mile change -55 ft net change -395 ft
Mile 24 4:25 / 3:41PM mile change -35 ft net change -430ft
When runners enter Boston for good at 24.5 miles they have ahead of them one of the great finishing spectacles in sports. Hundreds of thousands of cheering fans line Beacon Street to Kenmore Square, where the Citgo sign is well known as the one-mile-to-go mark.
Mile 25 4:36 /3:52PM mile change -45 ft net change -475 ft
The end has come I get to take the most famous turn of right on Hereford and left on Boylston. Where crowds of spectators urge on the runners to finish strong. I'd love to walk this last half mile or so down Boylston to take it all in but I'll probably be embarrassed to walk. 26.2 in the books it's time for a beer.