AnswerUpdated May 12, 2026

How to Start Ultrarunning

Start with a marathon or half-marathon base, then sign up for a 50K trail race as your first ultra — it's only 5 miles longer than a marathon. Build to 50–65 km/week over 12–16 weeks, include one long run of 3+ hours weekly, and practice eating while running. Most runners go from marathon to first ultra in 6–12 months.

The Short Answer

Getting into ultrarunningis simpler than most people assume. If you can run a marathon, you can run an ultra. The gap between a marathon (42.2 km) and a 50K (50 km) is just 7.8 km — less than most people's easy weekday runs. The real shift is mental: learning to pace conservatively, eat while moving, and embrace walking as a legitimate strategy.

The Roadmap

PhaseTimelineGoal
Build base fitnessMonths 1–340–50 km/week consistently, 1 long run >2h
Add durationMonths 3–550–65 km/week, 1 long run 3–4h, practice eating
Race-specificMonths 5–7Back-to-back long runs, simulate race nutrition
First 50K raceMonth 7–8Finish with a smile, learn for next time

Choosing Your First Ultra

Start with a 50K on a non-technical course. Flat road or smooth trail loops are ideal — they let you focus on pacing and nutrition without worrying about technical terrain. Choose a race with good aid station support so you can learn what works before needing to be self-sufficient. See our guide to choosing the best first ultra distance.

What Changes from Marathon to Ultra

Walking becomes a deliberate strategy, not a failure. Eating during the race is mandatory, not optional. Pace drops significantly — you're running to finish, not to hit a time goal. And the community is dramatically different: ultrarunners are welcoming, supportive, and nobody cares about your pace.

Sources

  1. UltraRunning Magazine — First-Timer Race Guides
  2. Millet, G.P. et al. (2011) — "Physiological differences between road and ultra running." Sports Medicine, 41(6), 477–497.

Go Deeper

Explore our comprehensive guides, training plans, and gear reviews for multiday running.