100k Training Plan and Ultra-Distance Tips
A 100K run is 62.1 miles of resilience and smart preparation. Whether you're completely new to ultra-distance racing or building toward an even bigger goal, this 16-week 100K training plan combines practical guidance and structured progression to help you reach the finish line.
What to expect from a 100km run
100K or 62.1-mile races exist for both road and trail running, with finish times ranging from 10 to 18+ hours, making it a true ultra-distance challenge. At over twice the length of a marathon, the 100K requires significantly more physical and mental energy. A 100K race training plan involves high training volumes and a focus on nutrition, while training for an ultra-trail adds variables like elevation.
Are you ready for a 100K training plan?
This 100K training plan assumes you’ve completed a marathon or 50K within the past 12 months and consistently run 35–40 miles per week.
Training for 100K: key concepts
When starting a 100K race training plan, focus on:
- The 80/20 rule: Follow this guideline for intensity and use intervals to practice proper breathing while running.
- Warm-ups: Try a dynamic warm up before races and training runs.
- Increasing distance, not pace: Speed shouldn’t be the goal, especially for your first 100-kilometer run; a long, slow effort is most beneficial. If you’re aiming for an ultra-trail, be sure to incorporate running at higher altitudes, too.
- Sleep: Aim for 7-9 hours per night.
- Fueling practice: Rehearse race-day nutrition on long runs from week 5 onward.
- Cross-training: Targeted strength trainingwork for runners helps prevent running injuries and improve efficiency.
- Back-to-back runs: Consecutive long runs help prepare your body for fatigue.
16-week 100K training plan
Keep most runs at a conversational pace. Intervals should feel challenging but sustainable, while tempo runs sit just below lactate threshold pace. If you’re seeking a 100K trail run training plan, consider adding intensity with hills (or stairs if you’re training for trails in a city). Repeat weeks 3–4, 7–8, and 11–12 to extend this to a 20-week 100K training plan.
Week 1
- Monday: Rest or strength training
- Tuesday: 6 miles
- Wednesday: 8 miles with 4x10-min intervals
- Thursday: 5 miles
- Friday: Rest or cross-training
- Saturday: 12 miles
- Sunday: 6 miles
Week 2
- Monday: Rest or strength training
- Tuesday: 7 miles
- Wednesday: 9 miles with 5x8-min tempo
- Thursday: 5 miles
- Friday: Rest or cross-training
- Saturday: 14 miles
- Sunday: 7 miles
Week 3
- Monday: Rest or strength training
- Tuesday: 7 miles
- Wednesday: 10 miles with 6x8-min tempo
- Thursday: 6 miles
- Friday: Rest or cross-training
- Saturday: 16 miles
- Sunday: 8 miles
Week 4
- Monday: Rest
- Tuesday: 5 miles
- Wednesday: 7 miles
- Thursday: 5 miles
- Friday: Rest
- Saturday: 10 miles
- Sunday: 5 miles
Week 5
- Monday: Rest or strength training
- Tuesday: 8 miles
- Wednesday: 11 miles with 5x10-min intervals
- Thursday: 6 miles
- Friday: Rest or cross-training
- Saturday: 18 miles
- Sunday: 9 miles
Week 6
- Monday: Rest or strength training
- Tuesday: 8 miles
- Wednesday: 12 miles with 4x12-min tempo
- Thursday: 6 miles
- Friday: Rest or cross-training
- Saturday: 20 miles
- Sunday: 10 miles
Week 7
- Monday: Rest or strength training
- Tuesday: 9 miles
- Wednesday: 12 miles with 5x10-min tempo
- Thursday: 6 miles
- Friday: Rest or cross-training
- Saturday: 22 miles
- Sunday: 10 miles
Week 8
- Monday: Rest
- Tuesday: 6 miles
- Wednesday: 8 miles
- Thursday: 5 miles
- Friday: Rest
- Saturday: 12 miles
- Sunday: 6 miles
Week 9
- Monday: Rest or strength training
- Tuesday: 9 miles
- Wednesday: 13 miles with 4x15-min intervals
- Thursday: 7 miles
- Friday: Rest or cross-training
- Saturday: 24 miles
- Sunday: 12 miles
Week 10
- Monday: Rest or strength training
- Tuesday: 9 miles
- Wednesday: 14 miles with 6x8-min tempo
- Thursday: 7 miles
- Friday: Rest or cross-training
- Saturday: 26 miles
- Sunday: 12 miles
Week 11
- Monday: Rest or strength training
- Tuesday: 9 miles
- Wednesday: 12 miles with 3x20-min race-pace
- Thursday: 7 miles
- Friday: Rest or cross-training
- Saturday: 22 miles
- Sunday: 10 miles
Week 12
- Monday: Rest
- Tuesday: 6 miles
- Wednesday: 9 miles
- Thursday: 6 miles
- Friday: Rest
- Saturday: 14 miles
- Sunday: 7 miles
Week 13
- Monday: Rest or strength training
- Tuesday: 8 miles
- Wednesday: 12 miles with 4x15-min race-pace
- Thursday: 7 miles
- Friday: Rest or cross-training
- Saturday: 20 miles with race-day gear and nutrition
- Sunday: 8 miles
Week 14
- Monday: Rest
- Tuesday: 7 miles
- Wednesday: 10 miles with 3x10-min intervals
- Thursday: 6 miles
- Friday: Rest or cross-training
- Saturday: 16 miles
- Sunday: 7 miles
Week 15
- Monday: Rest
- Tuesday: 6 miles
- Wednesday: 8 miles with 2x10-min intervals
- Thursday: 5 miles
- Friday: Rest
- Saturday: 12 miles
- Sunday: 5 miles
Week 16
- Monday: Rest
- Tuesday: 4 miles
- Wednesday: 5 miles with 3x5-min intervals
- Thursday: 3 miles
- Friday: Rest
- Saturday: Rest or 2-mile jog
- Sunday: Race
Training for 100K: mental endurance
Ultra distances test both physical and mental endurance. Use your 100km training plan to accustom yourself to mentally pushing through fatigue.
100K nutrition and hydration strategy
Proper nutrition before a race (as well as during) is imperative for running 100K, so fuel up prior to the start. During longer efforts, many runners aim for 60–90g of carbs and regular hydration each hour. You can use your 100K training to trial flasks and reservoirs for easy access to water. Gels provide quick energy, but pack salty snacks and solid foods, too, for sodium and variety.
100K race essentials
Equipment is key in a 100km run, especially on trails, where trail running gear keeps you safe. For mountain ultras, find specific trail running shoes and consider training with poles. Impact builds over 100K, so test trail shoes that are comfortable for long distances.
Having a way to drink water on the trails or the road is non-negotiable. Certain other trail running equipment, such as a headlamp for running safely at night, is equally useful on the road, too.
100km run: race and recovery
How long does a 100K run take?
Most trained runners finish between 10-18 hours depending on the course; trail-specific effort management may include more walking and take longer than road running.
What is a good 100K run time?
Sub-12 hours is a competitive finish on a standard course. For your first 100K, sub-16 is a good goal.
What to do after a 100K run?
Replenish fluids and electrolytes immediately afterwards, eat within 30–45 minutes, and avoid running for two weeks. You’ll be sore in the subsequent days, particularly after a trail run. Uphill efforts and downhill running load the legs differently, so trail race recovery may take longer.
100K: an ultra training plan for the long run
For many runners, the 100K is the first step into ultra-distance racing. Success requires a longer build, calibrated fueling strategy, and good sense of gear before race day. This 16-week 100K training plan provides a structured breakdown for building endurance and overcoming fatigue so you can join the ultra community.
Explore training plans for shorter distances: