Ultramarathon Training: How to Train for Your First 50K
A practical guide to training for your first ultramarathon: building mileage, back-to-back long runs, hiking, fueling, and pacing for a 50K and beyond.
May 23, 2026 · 2 min read
Training for your first ultramarathon — most commonly a 50K, or 31 miles — builds on marathon fitness with higher weekly volume, back-to-back long runs, and deliberate practice of hiking and eating on the move. Time on feet matters more than speed, and most ultras are run (and walked) on trails, so terrain practice is essential.
How ultras differ from road marathons
- Distance: 50K and up, often on trails with significant elevation.
- Pace: slower and more even; walking the hills is expected, not a failure.
- Fueling: longer time on feet means real food and steady calories matter.
- Terrain: technical footing demands ankle strength and careful focus.
Back-to-back long runs
The signature ultra workout is the back-to-back long run: a long effort on Saturday followed by another on Sunday. This teaches your body to keep going on already-fatigued legs — exactly the demand of late-race ultra miles — without the recovery cost of a single enormous run.
Learn to hike
In an ultra, efficient power-hiking up climbs is faster and far more sustainable than trying to run everything. Practice a strong, hands-on-knees hiking gait on steep terrain during training. It conserves energy and keeps your legs fresher for the runnable sections.
Eat early and often
Ultrarunners often aim for 200–300 calories per hour from a mix of gels, real food, and drink. Start fueling early — once you're behind on calories in an ultra, it's very hard to catch back up.
Sample weekly framework
- Two to three easy runs during the week, including hilly terrain.
- One midweek moderate or tempo run for sustained effort.
- A weekend back-to-back: long run Saturday, second long run Sunday.
- At least one full rest day, plus strength work for durability.
Frequently asked questions
How long is a 50K ultramarathon?
A 50K is 31 miles, just under 5 miles longer than a marathon. It's the most common entry-level ultra distance and a popular first step beyond 26.2.
Do I need to run the full distance in training?
No. Like marathon training, you build to long runs and back-to-backs that total significant distance without covering the full 50K. Time on feet and consecutive long efforts prepare you better than one huge run.
Is it okay to walk during an ultramarathon?
Absolutely — it's expected. Even elite ultrarunners hike the steep climbs. Strategic walking conserves energy and is a core skill of successful ultra racing.
Put it into practice
Let Coach Ben build your plan.
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