L's key takeaway: A hill session involves repeating climbs at a hard effort, each followed by an easy descent that lets you recover. Hold back from the very first climb: the last one should feel like the first. Start with short repetitions on a gentle slope, then make them longer as the session gets easier.
On a Breton hill, the same climb comes around on every lap, and that’s where the session is made. The problem is gauging your effort on each climb without knowing how many repetitions you can manage. This article gives you a trail hill session to try on your next run, with repetitions, recovery periods, and guidelines for adapting it to your level.
Contents
- Trail hill session: repeated climbs at a steady effort
- Choose a 5 to 7% gradient on safe terrain
- Short and long hills: two formats for two different qualities
- Start or resume without overdoing it
- How do you combine climbs, flat sections, and descents in a run?
- Active downhill running: an integral part of training
- FAQ
Trail hill session: repeated climbs at a steady effort
Return to the same hill, a trail climbing through the ferns, and repeat it at a steady effort: that’s the principle behind a hill session. Before you start, plan a 20-minute warm-up jog with a few progressive accelerations. The session then alternates between hard-effort climbs and easy recovery periods. Each climb ends with an easy descent that gets your legs ready for the next one. Sprinting at the top is pointless here: the goal is consistency, not an all-out effort.
The classic trap is the first climb: you start too fast. Pick a visible landmark at the top of the hill and maintain the same effort all the way to the end. Hold back at the start; the final climb will reward you. Uphill, keep your hips high, your upper body relaxed, and your arms active. Plant your foot, brace, and push without lengthening your stride. If you’re a beginner, check out our guide to getting started with trail running.
Choose a 5 to 7% gradient on safe terrain
A 5 to 7% gradient gives you 5 to 7 m of elevation gain per 100 m of flat terrain: it’s a slope that keeps your stride steady. For beginners, staying around 5 to 6% is a good option. Above 15 to 20%, walking is often the right call, even for experienced runners. To make progress over the long term, also see how to improve at trail running.
To find a safe hill and adapt your workout on the spot, check these four things:
- Length: 100 to 200 m is enough for 25-second repeats. If the hill is too short for the planned duration, continue on flat ground after the top.
- Slope: it should be consistent, so you can run without breaking stride.
- Surface: choose a stable path with good grip and few stones. Slippery or uneven? Ease off.
- Access: it should be wide enough to run and walk back down without getting in anyone's way.
Short and long hills: two formats for two different qualities
Short hills: 8 to 12 fast climbs of 25 seconds
On a 100- to 200-meter hill, attacking the first climb too hard is the most common mistake: the last repeats then end in a walk. A typical workout is 20 minutes of warm-up, followed by 8 to 12 climbs of 25 seconds. For your warm-up, follow the complete running routine. Then allow 5 to 10 minutes to jog back down: the workout takes less than 45 minutes. On a short hill, gauge your effort by feel, not by your watch. Here's what differs between the two formats:
| Criterion | 25 seconds | 30 seconds |
|---|---|---|
| Run back downhill | Walk or jog easily, then recover for about 1 minute | About 40 seconds downhill |
| Effort level | Go by feel and keep your running form steady | Go by feel and keep your running form steady |
| Speed | No fixed speed: it varies with the slope and with you | No fixed speed: it varies with the slope and with you |
The last climb should feel like the first: that's the only real sign of a well-paced workout.
Long hills: 4 to 6 climbs of 7 minutes at a steady pace
On a long hill, setting off too fast on the third climb is a classic pitfall. To last 7 minutes without burning out, aim for 80 to 85% of your maximum heart rate and keep a steady pace. Once that feels easy, move on to tempo runs: start with 3- to 4-minute repeats, then extend them to 6 to 8 minutes. No need to rush the process; you'll benefit in the long run.
Start or resume without overdoing it
Your first time on a hill? Keep it short. About ten minutes is enough. Choose a gradual slope and terrain without technical challenges. Do 4 to 6 climbs of 30 to 60 seconds at a strong but controlled effort. Between each one, walk or jog back down to the start. It's better to stop before you feel pain: your next session will be all the better for it.
For help fitting hill sessions into your week, see the 30 km trail running training plan and keep these rules in mind:
- You can include one or two hill sessions per week in your trail running program.
- Leave at least 48 hours between two interval sessions, and never schedule two hard sessions on consecutive days.
- In a five-day running week, schedule hill training for Thursday, an easy long run for Saturday, and rest on Wednesday. Keep your other runs easy.
How do you combine climbs, flat sections, and descents in a run?
Hill fartlek is done on a hilly run lasting at least 20 minutes. Pick up the pace on the climbs, then ease off on the flat and downhill sections. At first, keep your recovery easy, at around 20 to 30% effort: many runners start too hard and can no longer pick up the pace. As you improve, increase to 60% effort. Before your accelerations, check out the three-phase warm-up routine.
On a drizzly morning on the plateau, a typical loop looks like this: 100 m uphill, 1 km flat, 100 m downhill. The flat section is the trap: your legs relax before you know it. At the end of the descent, accelerate for 45 to 60 seconds, then recover as you return to the start. Tip: do just one loop at first, not two.
Active downhill running: an integral part of training
On downhills, many runners brake with every step, putting the strain on their knees. Shorten your stride and keep your upper body leaning slightly forward. Look at the trail ahead to choose your footing. Your quadriceps lengthen as they brake and control your descent: this eccentric work makes you stronger on long downhill stretches. On a soaking-wet descent, taking long strides with your torso leaning back is the best way to end up sitting in the mud. Avoid this posture.
Slippery ground? Slow down and walk until you reach a safe stretch. During recovery, jog slowly: allow about 40 seconds after a 30-second climb. For other ways to improve, see practical strategies. On muddy ground, walking without regret is always the right call.
Remember one thing: a hill workout is based on steady effort, from the first repetition to the last. Don't wear yourself out at the bottom; you'll feel it on the final climb. This week, choose a short, steady hill, then do your first workout without chasing a personal best. At your next workout, you'll know what to make longer. The right gear also matters for running light uphill: discover men's trail shirts and women's trail shirts Kinetik, designed for uphill efforts.
FAQ
What's the difference between 15/15 and 30/30 hill intervals?
The duration is what changes. 15/15 alternates 15 seconds of effort with 15 seconds of recovery, while 30/30 alternates 30 seconds of effort with 30 seconds of recovery. In both cases, keep your effort steady and recover by jogging or walking.
What pace should you aim for during 30/30 hill intervals?
Aim for a strong pace you can repeat without compromising your stride, not a sprint. The incline changes everything: on a steep hill, the effort ramps up quickly, so adjust it on each climb. If your stride shortens before you reach the top, you started too fast.
How many hill workouts should you do per week?
You can do one or two hill workouts per week. Leave at least 48 hours between interval sessions, and never do two hard workouts back to back. If you only do one, that's already good.
Can you replace hill training with an inclined treadmill?
Yes, when you don't have an accessible hill, an inclined treadmill can replace a hill workout. But keep running outdoors: a treadmill will never let you feel muddy ground or a waterlogged descent.