An ultra marathon is any running event longer than the standard marathon distance (42.195 kilometers or 26.219 miles). The most common ultra distances are 50 kilometers (about 31 miles), 50 miles (about 80 kilometers), 100 kilometers (about 62 miles), and 100 miles (about 161 kilometers), though races can be longer and may be staged over multiple days or stages.

Key points to know:

• Definition
  • Ultra = any distance longer than a marathon. Many races settle into familiar benchmarks like 50K, 50 mile, 100K, and 100 mile distances.

• Typical distances
  • 50K (roughly 31 miles) is a common entry point for new ultra runners; 50 miles and 100K/100 miles are other popular formats. Some events span multi-day stages.

• Examples of formats
  • Single-stage ultras: you complete the entire distance in one continuous effort (e.g., UTMB, Comrades Marathon).

* Multi-stage ultras: distance completed over several days with daily segments (e.g., Marathon des Sables).

• Common definitions in resources
  • A standard marathon is 42.195 km; ultras are anything longer, with several standard mileages frequently cited in guides and race catalogs.

If you’d like, I can tailor this to a specific ultra distance, region, or race type (trail vs road, single-day vs multi-day) and include recommended training targets.