Strength training guide for ultra runners: Building the engine for the long haul

By Henry Howard

Ultra running is a different beast. When you’re out on the trail for eight, 12, or 24 hours, running stops being about speed and starts being about durability. Your body needs to function efficiently not just for miles, but for vertical gain, technical descents, river crossings, and gnarly terrain.

That is why strength training for trail and ultra runners becomes not just beneficial, but critical.

This strength training guide for ultra runners is part two of a special four-part series. The first installment covered why strength training is essential for runners, how to incorporate it into your routine, and the best upper body exercises to improve performance and prevent injury.

(Thanks to my friends at AmazFit for their support of this series. I recently tried the AmazFit T-Rex 3 Pro watch and honestly found that it is a better option than Coros and Garmin, which I had worn for 15 years. Check out my review here. And if you are interested in an AmazFit watch, you can save 10% with my discount code RUNSPIRITED at this link.) 

Why strength training is critical for ultra runners

The demands of ultra running expose every weakness in your kinetic chain. Road marathoners might get away with muscular imbalances for 26.2 miles, but ultra runners face a much longer reckoning.

Whether you run ultras in the mountains or on flat canal trails or similar surfaces, your body needs to withstand the punishment. Fatigue doesn’t just slow you down, it compromises your form, increases injury risk, and can turn a manageable downhill into a quad-destroying nightmare.

Consider what happens during an ultra with hills or mountains.

You’re navigating uneven terrain that requires constant stabilization from your ankles, knees and hips. You’re climbing thousands of feet of elevation, demanding explosive power from your glutes and quads. Then you’re descending those same climbs, requiring eccentric strength to control your speed and protect your knees from the pounding. Many runners also carry heavy packs, further increasing the need for solid strength.

Research on ultra runners shows that muscular fatigue, not cardiovascular fatigue, is often the limiting factor in performance. Your aerobic system might be ready to keep going, but if your quads are shredded or your hip stabilizers have given up, you’re reduced to a shuffle or forced to drop.

Strength training builds the muscular endurance and resilience to keep your form intact when exhaustion sets in.

Additionally, ultra running in mountainous terrain requires a strength profile different from road running. You need powerful glutes and quads for sustained climbing, bulletproof eccentric strength for downhill pounding, and rock-solid stability to handle technical terrain when you’re exhausted. You can’t build these qualities through running alone.

A specific approach to strength building for ultra runners

Ultra runners need a strength program that emphasizes three key qualities: power for climbing, eccentric strength for descending and single-leg stability for technical terrain.

Unlike road runners who generally focus on traditional bilateral movements, ultra runners benefit enormously from single-leg exercises for trail running that mimic the unstable, uneven nature of trail running. These exercises build the stabilizer muscles around your ankles, knees, and hips that keep you upright on rocky trails and prevent rolled ankles.

Training frequency remains similar — two sessions per week — but the exercise selection and rep schemes differ. Runners benefit from higher rep ranges (12 to 15 reps) that build muscular endurance for ultra running alongside strength. You’re not trying to lift the heaviest weight possible; you’re building muscles that can contract efficiently for hours on end.

Periodization matters for ultra runners.

In the early off-season, focus on building maximum strength with heavier weights and lower reps. As you move into your training cycle, shift toward higher-rep, lower-weight exercises that better mimic the sustained muscular demands of ultra running. In the final weeks before a race, maintain strength with lighter sessions that don’t compromise recovery.

Essential strength training exercises for ultra runners

Lower body power and endurance

Box step-ups with weights: Hold dumbbells at your sides and step up onto a box that brings your knee to 90 degrees. Drive through your heel and fully extend your hip at the top. This mirrors the climbing motion in mountain ultras. Do 3 sets of 15-20 reps per leg.

Bulgarian split squats: Place one foot on a bench or chair behind you, lower into a split squat on the front leg. This builds single-leg strength crucial for uneven terrain. Perform 3 sets of 12-15 reps per side.

Eccentric squats: Lower slowly (4-5 seconds) into a squat, then rise at normal speed. This builds the eccentric strength that protects your quads on downhills. Complete 3 sets of 10-12 reps.

Walking lunges: Take long strides forward, lowering until your back knee nearly touches the ground. These build functional strength through a full range of motion. Do 3 sets of 20 steps (10 per leg).

Calf raises on stairs: Stand on bottom stair, rise onto your toes, hold briefly, then lift one foot off step and lower slowly. Return foot to step and repeat up and down movement. Then do other leg. Strong calves are essential for both climbing and technical terrain. Work up to 2 sets of 20-25 reps per leg.

Stability and balance

Single-leg deadlifts: Stand on one leg, hinge at the hip while extending the other leg behind you, reaching toward the ground with your hands. Return to standing. This builds posterior chain strength and balance. Do 3 sets of 10-12 reps per side.

Lateral lunges: Step wide to the side, shifting your weight onto that leg while keeping the other leg straight. This strengthens the hip abductors and adductors critical for lateral stability. Perform 3 sets of 12 reps per side.

Single-leg box touches: Stand on one leg in front of a low box, slowly lower to tap the box with your opposite hand, then return to standing. This challenges balance while building strength. Complete 3 sets of 15 reps per leg.

Stability ball hamstring curls: Lie on your back with heels on a stability ball, lift your hips, then curl the ball toward you by bending your knees. This builds hamstring strength while challenging stability. Aim for 3 sets of 12-15 reps.

Pistol Squats (or progressions): Single-leg squats to full depth. Start with assisted versions using a TRX or holding a pole. Ultimate single-leg strength builder. Work toward 3 sets of 8-10 per leg.

Core and posterior chain

Plank variations: Hold a forearm plank for 45-60 seconds, then add challenges like lifting one leg or one arm. Ultra running requires sustained core stability. Do 3-4 sets.

Glute bridges: Lie on your back, feet flat, lift your hips toward the ceiling. Hold for 2 seconds at the top. Do 3 sets of 20-25 reps.

Dead bugs: Lie on your back, extend opposite arm and leg while keeping your core engaged and back flat. This builds core stability with movement. Perform 3 sets of 12-15 reps per side.

Nordic hamstring curls: Kneel with your feet secured, slowly lower your body forward, controlling the descent with your hamstrings. Push back to the starting position. This builds exceptional eccentric hamstring strength. Start with 2 sets of 10 reps, progressing slowly. (Note: I have a device for this exercise that slips under a door and secures your feet in place. Amazon has lots of options.)

Ultra running workout plan

A weekly guideline that I might create for my runners might look like this:

• Monday: Rest day, yoga recommended.

• Tuesday: Easy run with hill repeats or other speed work.

• Wednesday: Workout run with longer intervals in the morning, strength training either afterward or later in the day.

• Thursday: Easy run.

• Friday: Cross-training bike ride, elliptical, etc.

• Saturday: Long run, strength training either afterward or later in the day.

• Sunday: Easy recovery run or bike ride.

During your build-up to an ultra, maintain strength work but reduce volume if and when you need additional recovery from running. In the final two weeks, drop strength work entirely to ensure fresh legs on race day.

Remember that ultra running is an endurance sport, and that includes muscular endurance. Your strength training should reflect this. You’re not trying to set powerlifting records; you’re building a body that can handle whatever the trail throws at you, hour after hour.

The trail is unforgiving, but a strong body is resilient. Put in the strength work now, and when you’re in the latter stages of a 100-miler, you’ll still be moving efficiently while others are falling apart. That’s the ultra runner’s edge.

Frequently Asked Questions: Strength training for ultra runners

Q: Should I do strength training during ultra marathon training peak?

A: Yes, but reduce volume and intensity as needed to ensure full recovery. You are a runner first and we want the workouts to be quality runs, especially during peak mileage weeks. Maintain the movement patterns but don’t chase progressive overload. The goal is maintenance, not gains.

Q: Will strength training help with downhill running?

A: Absolutely. Eccentric-focused exercises like eccentric squats, Nordic curls and controlled step-downs directly build the quad strength needed to brake on descents. Many ultra runners report significantly less quad damage after implementing eccentric training for downhill running.

Q: What about during a training camp?

A: Skip formal strength training during multi-day efforts. Your running is providing enough muscular stress. Focus on recovery, mobility work and fueling instead.

Q: Should I lift heavy or focus on high reps?

A: Both have value at different times. Build maximum strength in the off-season with heavier weights (6-10 reps). As race season approaches, shift to higher reps (12-15) to build muscular endurance. This periodization optimizes both strength and endurance.

Q: How important is upper body work for ultra runners?

A: Very important, especially for mountain ultras. You’ll use trekking poles, scramble over rocks and carry a pack for hours. Strong shoulders, back, and arms maintain your posture and allow efficient pole use. Include push-ups, rows, and overhead presses weekly.