Why poles earn their keep on the fells

On a smooth towpath, trekking poles are a luxury. On the sort of ground you meet across the Lakeland fells, the boggy tops of the Peak District or a rough Highland track, they become something much closer to a third and fourth leg. Every firm plant takes a share of the load that would otherwise land squarely on your knees, ankles and hips, and over a long day that saving adds up.

The catch is that poles only help when they're set up properly. Too long and they jab at the ground before your foot arrives, pushing you upright and off balance. Too short and you walk hunched over like a question mark. Both are worse than leaving them in the car.

Getting the flat-ground length right

Start on level ground. Stand upright, put the tip on the floor beside your boot, and rest your hand on the grip. Your elbow should sit at roughly a right angle, with your forearm parallel to the ground. A useful shortcut is that the top of the grip should come to about armpit height — a little higher if you like a longer stride, a little lower if you're descending steep ground often or carrying a heavy pack.

Set both poles to the same length, then check the locks. Twist locks can slip after a few hours of vibration, and flick locks can be knocked open by a rock. Give each shaft a firm tug before you set off and again before any big descent. Wiping grit off the lower sections at the end of a walk keeps them working smoothly for years.

Shorter for the climb, longer for the descent

This is the adjustment that most people skip, and it's the one that makes the biggest difference. On the way up, shorten both poles by around five to ten centimetres. A shorter pole lets you plant close to your feet and push down and back, which takes weight off your legs and helps drive you uphill. On steep ground, don't fiddle with the locks — simply cup your palm over the top of the grip for a shorter effective length.

Going down, lengthen them by the same amount. A longer pole reaches the ground ahead of you so you can take weight before your foot commits, and it gives you something to lean into. On a genuinely steep descent you can lower yourself down almost as if using crutches. If you find yourself stretching to reach the ground, you've gone too far; if the pole feels like it's tripping you, shorten it.

Planting firmly when the ground is rough

• Place the tip deliberately. Don't stab at the ground at random. Feel for a solid spot — a rock edge, a patch of firm turf, the top of a tussock — before you put any weight through it.
• Keep the pole fairly vertical. A pole planted at a steep angle will slide out from under you on wet grass or loose scree.
• Use the wrist straps. Slide your hand up through the loop from below, so the strap crosses the back of your hand and you grip strap and handle together. The strap then carries the load through your palm rather than your fingers doing all the work.
• Keep a rhythm. Left pole with right foot, right pole with left foot. Once it becomes automatic you'll use noticeably less energy.
• Probe the ground. In heather, deep tussocks or bog, use the poles to test what's underfoot before you commit your weight. They'll find the hidden holes that ankles don't forgive.

Keep the baskets on for soft ground, so the poles don't sink to the hilt in peat, and swap to rubber tips if you're on long stretches of road or lakeside path, where metal tips skitter and wear quickly.

Looking after knees and ankles

The real prize is on the descents. Coming down a rough pitched path, each step sends a jolt through the knee joint, and by the end of a long day that's the difference between a happy pint and a stiff, painful evening. Poles spread that load: you take some of it through your arms and shoulders, and your legs get a rest between steps. If you've ever had trouble with your knees, a heavier pack, or a long walk out at the end of the day, this is where poles pay for themselves.

They also help with balance on the awkward stuff — greasy rock, stepping stones, the muddy churned section just past a gate. Two poles planted wide give you a stable triangle or square of support, and a stumble becomes a wobble rather than a fall.

When to put them away

There are places where poles get in the way. Anywhere you need your hands for scrambling, stow them — collapsed and strapped to the side of your pack, or one at a time if the ground alternates. The same goes for crossing stiles and ladder gates, where a pole swinging about is a nuisance and a hazard.

And if the terrain is easy and the day is short, there's no shame in leaving them at home. Poles are a tool, not a uniform. But on a long rough day in the hills, set to the right length and planted with intent, they'll quietly carry you further than your legs would manage alone.