Astronaut Sunita L. Williams, Expedition 14 flight engineer, equipped with a bungee harness, exercises on the Treadmill Vibration Isolation System (TVIS) in the Zvezda Service Module of the International Space Station.

The 41-year-old plans to run the 26.2-mile race on a treadmill onboard the International Space Station on Monday, April 16, at 10 a.m. EDT. This year’s marathon also starts at 10 a.m. on Monday.