Spring
More people have been to space than have completed the Marathon Grand Slam. That single fact tells you almost everything you need to know about how exclusive endurance running can get — and, fittingly, one of the rarest feats in the sport actually happened in orbit.
This article covers two of the most talked-about "rarest of the rare" marathon achievements: the Marathon Grand Slam, an earthbound club with fewer than a couple hundred members worldwide, and the space marathon, a feat only two humans have ever completed. If you searched for either topic, here's what you need to know.
The Marathon Grand Slam Club® is an exclusive membership for runners who have completed a full marathon (26.2 miles / 42.195 km) on all seven continents plus the North Pole Marathon — a race run at a drifting ice camp in the Arctic Ocean, often in sub-zero temperatures.
The club is owned and managed by Runbuk, Inc., and membership isn't just about crossing finish lines — every claim has to be authenticated, and participants must first belong to The 7 Continents Marathon Club before qualifying for Grand Slam status.
As of August 1, 2026, the Marathon Grand Slam Club counted just 200 members — 150 men and 50 women — representing 43 countries and regions. For comparison, well over 700 people have flown to space. Finishing a marathon on every continent and at the North Pole remains one of the toughest endurance and logistics challenges a runner can take on, requiring years of travel, race planning, and cold-weather training most marathoners never encounter.
New members receive a Marathon Grand Slam Club medal and certificate.
A "space marathon" refers to an astronaut completing the full 26.2-mile marathon distance — as measured on the treadmill belt — aboard a crewed spacecraft in orbit, on a specially harnessed treadmill, in microgravity, timed to coincide with an actual marathon happening on Earth. The spacecraft itself travels much farther during that time — Peake pointed out afterward that the International Space Station covered nearly 100,000 km while he covered 42 km on the belt.
Only two astronauts have publicly documented completing a full marathon distance in space:
The two times aren't directly comparable: Williams and Peake used different treadmills and harness systems with different loads, so, as The Guardian noted at the time, the times reflect different equipment as much as different pace. Guinness's category name is also specific — "fastest marathon in orbit," not "in space" — since orbit, not altitude, is what defines the feat.
Both runs required harness systems to press the runner against the belt. The station is in continuous free fall, so crew and treadmill accelerate together and there is no contact force underfoot — the harness supplies it artificially.
Nearly two decades after her space marathon, Williams — now retired from NASA — is set to run the 2026 Boston Marathon on the ground, having been named a recipient of the Patriots' Award for her contributions to sportsmanship and inspiration. It's a full-circle moment for the astronaut who once completed the same race roughly 210 miles above the Earth's surface.
Marathon Grand SlamSpace MarathonWhat it requiresA marathon on all 7 continents + North PoleA marathon-distance run on a treadmill aboard a crewed spacecraft in orbitTotal finishers (as of 2026)200 people2 peopleFirst completedOngoing club since early 2000s2007 (Sunita Williams)Primary challengeGlobal travel, extreme climates, logisticsContinuous free fall, harness systems, orbital mechanics
How many people have completed the Marathon Grand Slam?
As of August 1, 2026, 200 people — 150 men and 50 women, from 43 countries and regions — have completed the Marathon Grand Slam Club requirements.
Who was the first person to run a marathon in space?
Sunita Williams, an American astronaut, was the first person to run a marathon in space, completing the 2007 Boston Marathon on a treadmill aboard the International Space Station in 4 hours and 24 minutes (per Guinness World Records; some contemporaneous reports list slightly different times).
Has anyone else run a marathon in space besides Sunita Williams?
Yes. British astronaut Tim Peake completed the London Marathon distance aboard the International Space Station in 2016, finishing in 3 hours, 35 minutes, 21 seconds — a faster time, though the two runs used different treadmills and harnesses and aren't directly comparable. Both are, so far, the only publicly documented marathons run aboard a crewed spacecraft in orbit.
What continents count toward the Marathon Grand Slam?
Africa, Antarctica, Asia, Australia, Europe, North America, and South America — plus the North Pole Marathon, which is required in addition to the seven continents.
Have a marathon goal of your own — whether it's your first 26.2 or a bucket-list challenge like the Grand Slam? Explore more here.
