From the east footbridge, loop around the circle in Richard McKinnon park—119 laps for the half, 56 for the 10K. Both events will start at the same time.
The direction will flip periodically, and you must change directions only by rounding the marker placed at the edge of the finish line. We cannot provide you an official time unless you follow these instructions and complete the necessary number of laps.
Members of the MIT community and invited guests.
No. Participants running or walking fewer than 119 laps are welcome to join. Here are some lap counts for common distances. Add a lap if not starting at an official start line.
| Distance | Laps |
|---|---|
| 5k | 28 |
| 10k | 56 |
| 10mi | 91 |
You may run as fast or as slow as you please. The course does not close, but folks probably won't stick around past noon.
On May 16, the temperature in Boston typically ranges from 52°F to 63°F and is rarely below 45°F or above 77°F. [...] The coolest time of the day is from 1:00 AM to 7:30 AM, with the coldest at 5:15 AM, at which time the temperature is below 55°F three days out of four, and below 61°F nine days out of ten.
You can stash a bag near the aid station. You'll have line of sight the whole race, but they won't be attended.
Use a running watch to mark laps if you're wearing one, though you should check that it can handle 100+ laps. GPS will clip the curve, so don't rely on it for more than a couple laps at a time. We'll have tally counters available if you prefer an analog counting aide.
Our experimental phone-based lap-counting service will also be available for all registered runners. We recommended using it as a backup for another method of counting.
Counting without assistance is not recommended.
The race will begin counterclockwise and alternate directions every 30 minutes to help balance the strain across your legs. Change directions only at the end of a lap and only by rounding the finish line marker.
Official times will be determined by the live tracking system. Runners not using the system may submit GPX tracks for inclusion in the results.
We only recommend running a safe number of laps given your current conditioning. Consider alternating walking and running laps if you are worried about being able to complete the distance.
Yes. In addition to the aid station there are benches surrounding the course. You must continue running the lap in the same direction as when you stopped or the lap will not count. We recommend you start and stop only on at the lap finish line so you can begin the next lap in either direction.
Yes, but not substantially. You will need to supply an additional centripetal force due to the curve, but the effect of this is likely less than 1% when running at world record marathon pace on a 30m radius. Because the force increases in the square of velocity, the effect is negligible for recreational runners. There are individual differences in running technique and physiology that may make the effect more or less pronounced for you. Consider practicing on the course or a track.
Unlikely. Many athletes train and race on smaller radius tracks without issue during indoor track season. There is evidence that consistently running the same direction on small indoor tracks over time leads to strength asymmetries which likely cause injuries. Alternating directions is probably sufficient to avoid acute issues for most runners.
You may also take comfort from knowing that indoor track marathons have been held for years without problems.
Run from the start line and join us! You must enter the course from "behind" the finish line in the direction that the field is running. So, if we're running counterclockwise, start your first loop by crossing the line from the east, and otherwise from the west. Note that this event is gun time only.