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Image of the July 2023 Wilderness Magazine Cover Read more from the
July 2023 Issue

Is thru-hiking bad for me? A single question morphed into this 12-page feature in which experts answer the burning questions on so many trampers’ minds.

Why is the golden hour so good for photography?

The hour before sunset and after sunrise are known as the ‘golden’ or ‘magic’  hours. The sun is lower in the sky, which provides the best light to capture the best photos.

Christchurch photographer Dennis Radermacher regularly shoots at these times. “It’s a magic thing. It’s very pretty light,” he says. “Two effects come together: the angle of the light and the amount of air the light travels through. When the sun is low in the sky, light hits the ground at a flat angle and casts long shadows, and is softened because it travels through a lot more air. Moisture in the atmosphere also helps scatter the light, and you end up with directional sunlight that’s soft and warm.”

Soft lighting is flattering, warm light creates an orange glow often associated with calm and happiness. Colours and contrasts are more vibrant.

“To appreciate light, it needs to be in contrast to something, such as the absence of light, like the shadows,” says Radermacher.

Poles increase balance and stability

What do walking poles actually help with?

A 2020 review of walking pole research in Wilderness & Environmental Medicine collated many studies to determine whether poles helped or hindered.

The authors concluded that the studies showed poles can provide better balance and reduce load through the hip, knee and ankle joints, but users will burn more energy doing it: ‘Trekking poles decrease lower extremity loading and forces but increase cardiovascular demand. When carrying a large external load, trekking poles may offer benefit by decreasing lower extremity muscle activity and increasing balance and stability.’

Poles can also help you walk faster, especially with a heavy load or when walking uphill. The studies showed that the use of poles allows a more normal   walking pattern, including a ‘longer stride length and a less flexed knee at heel strike.’

Do plants really suffer from being walked on?

Len Gillman, recently retired as Professor of Ecology and Biogeography at Auckland University of Technology has a lifetime of experience working with New Zealand flora. He says plants don’t feel pain, but “it depends what’s meant by suffering”.

“If it’s ‘do they feel pain?’, then no, because they don’t have a nervous system. But if it’s ‘can you damage them?’ then yes, you can definitely damage plants by walking on them.”

Gillman has worked in Antarctica with 200-year-old mosses, which would be killed if stood on. “It depends on the plant and its environment. A lot of plants are quite resilient to animals and people tramping all over them. But others, like the Antarctic moss, can suffer significant damage.”

Gillman says there are some environments where plants are particularly susceptible to trampling: “Often plants that grow in bogs are much more vulnerable, which is why boardwalks are put in boggy areas,” he says.

Damage in New Zealand is much greater from tahr, goats and deer than from people, says Gillman. “The damage these animals cause, especially in the high country, is horrendous. They can wipe out entire herb fields of endangered plants. Damage from people tends to be localised to around tracks.”

Fresh meals are yummier and contain more nutrients, but freeze-dried or dehydrated foods are much lighter. Photo: Matthew Chan

Is fresh food better than dehydrated or freeze-dried food? 

Freeze-drying, as the name suggests, slowly freezes and dries food under a vacuum, removing all the moisture. Food retains its shape and structure, much like a honeycomb, so that when water is added the structure fills and quickly rehydrates.

Dehydrated food is dried by long exposure to heat, which shrivels the food, often with a skin on.

Founder of Real Meals Nathan Fa’avae says the key differences between fresh food and dehydrated or freeze-dried are nutritional value, convenience and weight.

“Freeze-drying retains practically all the nutritional value of the food; the loss of nutrition is generally under one per cent,” he says. “Dehydrated food can sometimes lose more than this – it still has energy, it’s just not as nutrient-dense.”

One of the main advantages freeze-dried or dehydrated food has over fresh food is convenience. Fa’avae says: “You can make a fairly complicated, tasty meal with a cup of boiling water that would be very difficult to assemble on location using fresh food, because of the amount of ingredients needed.”

The other is weight. “They’re so light,” says Fa’avae. “Freeze-drying removes about 80 per cent, if not more, of the weight from a meal. Dehydrated food is only slightly heavier. Carrying 20–25 per cent of the weight of fresh food can make a huge difference to a load.”

Lichen grows as does any plant using photosynthesis. Photo: Len Gillman

How can lichen grow on rocks?

Lichens come in many colours, sizes and forms and are sometimes plant-like. But they’re not plants, says Professor Len Gillman.

“Lichen is a combination of two organisms that come from entirely different kingdoms: the thallus, or fungal, part of it and within that, an algae,” he says. “The algae can photosynthesise, the fungus can’t. The two organisms work together     to produce the lichen.”

When lichen attaches to a rock, it can grow as does any plant using photosynthesis. Its minerals largely come from dust particles that float on top of it or from the surface of the rock.

“They’re an amazingly versatile combination of organisms. They grow in extreme, inhospitable environments, where all other vegetation has disappeared.”

How do blisters form?

Rebecca Rushton BSC(Pod) is a podiatrist and blister thought-leader. In a recent research article published in the Journal of Athletic Training, Rushton challenged the common notion that blisters are caused by heat, moisture and friction. She argues that foot friction blisters are caused by repetitive shear deformation. There are three elements, including motion of bone, high friction force and repetition of the resulting shear events. ‘Rubbing at the skin surface is not a mechanism for friction blister formation,’ she said.

Rushton writes: ‘Think of it as the bones moving back and forth while the force of friction keeps the surface of your skin stationary. Friction isn’t rubbing – it’s the opposite – it’s the force that resists rubbing. There’s a lot of resistance to rubbing between your skin, sock and shoe – so much so that they all stay in stationary contact for longer than you think. Yet the bones move back and forth, and everything in between is made to stretch and distort.’

Blisters start with initial redness, followed by blanching, then a small pleat in the epidermis which subsequently fills with fluid. Rushton says the key to blister prevention is to reduce the friction with lubricants, blister powders, double socks and so on. The strategy is to make the skin’s surface move in sync with the bones with resulting lower shear distortions.

An empty Powelliphanta shell means the snail that made it has died. Photo: Toby Roberts

Why do Powelliphanta snails drop their shells?

“They don’t,” says mollusc specialist Kerry Walton, an invertebrate curator at the Museum of New Zealand Te Papa Tongarewa. “An empty shell is because the snail that made it has died.”

Walton is an external member of the Department of Conservation threat classification group for these giant land snails, which can weigh as much as a tuī. “Several species of Powelliphanta snail are critically endangered and many populations are showing alarming trends of decline.

“They’re extremely vulnerable to rats, weka, pigs and possums. Large herbivores also impact the snails by degrading the undergrowth, which makes it easier for predators to find snails and puts them at increased risk of dehydration.”

Walton says historical shell collection has contributed to the decline of some species. “All Powelliphanta species are now protected by the Wildlife Act – the same protection that applies to kiwi and tuatara – so they should be left alone if trampers encounter them.”

Why do raincoats lose effectiveness over time?

Greg Foord, manager for outdoor equipment distributor Spelean, knows a thing or two about raincoats.

“Waterproof jackets are treated with a durable water-repellent (DWR),” he says. “It’s generally applied to the fabric’s exterior, so the material doesn’t absorb water and get saturated. When the finish is in good condition, water droplets bead and roll off.”

Over time, the water repellent deteriorates. “There are several reasons,” Foord says. “The way the jacket is washed, how often it’s washed, abrasion from packs or things on the track, general heavy use or pollutants from having a dirty jacket.”

Foord says it’s a myth that you shouldn’t wash your waterproofs. “Pollutants degrade the DWR so it’s less water resistant. Fabric breathability will also be reduced making the inside of the jacket sticky and dirty.”

Foord advises using a mild soap or a special wash for technical waterproof and breathable fabrics and using a clothes dryer on a low heat afterwards to help reactivate the DWR.

“A waterproof jacket usually lasts three to five years. However, with proper care and cleaning, it can last up to 10 years if you re-proof every so often.”

Why are YKK zips used on everything?

“Because they’re so good,” says David Ellis from Earth Sea Sky. “They have honed their craft so much that no one has come close to offering the range or technology they offer. They’re way ahead of the game.”

The Japanese company is the world’s largest zipper manufacturer and has been operating since 1934, registering the YKK trademark in 1946. It produces fasteners and architectural products in 71 countries.

Macpac’s Martin Tatchell agrees with Ellis. “Anything else is seen as less superior. Their brand name adds value and quality to a product.”

Gaiters keep feet dry and protect boots, legs and clothing

Are gaiters worth it?

Yes, says the director of Hiking New Zealand Dan Murphy.

He adds that the need for gaiters depends on the track and expected conditions.

“If I know I’m going to be doing off-track hiking, river crossings, or if there’s going to be snow, I’ll definitely take my gaiters. You can skip across a creek that’s below gaiter height and not get wet.”

Gaiters are worn over the shoe and bottom of the leg, usually to mid-calf. They’re made of sturdy weather-resistant materials and are designed to protect the foot and lower leg from snow, water, or debris.

“In rough, challenging terrain, especially in the backcountry, they’ll stop grit, mud and stones getting into boots and protect your legs from vegetation,” says Murphy.

Odour control treatments prevent odour-casuing bacteria clinging to the garment’s fibres

How does odour control treatment in clothing work? 

“Synthetic fibres are solid, so if anything comes off your skin, like bacteria or odour, it just sits on the surface of the fibre and builds up, creating a smell until it’s washed,” says David Ellis.

“Once you wash something, detergents normally clear out the surface and it returns to normal odour-free conditions. Polypropylene has very rough surfaces. So when odour particles come off the skin and contact the surface of the fibre, it will ‘lock’ onto the synthetic’s surface. This is difficult to prise off with detergent.”

Odour control is a surface treatment that prevents anything from attaching to the fibre. Clothing becomes odour resistant and easy to wash and clean. However, it’s worth noting that their effectiveness is reduced over time.

The unprotected tips of walking poles are known to damage tracks

Do walking poles really damage tracks?

A study in 2011 by DOC project manager John Wilton on pole usage on the Tongariro Alpine Crossing estimated 20 per cent of people walking the track used poles. Of those, only two per cent had fitted the protective rubber cap to their poles.

Wilton noted: ‘In general, walkers treading on the track surface have a positive effect, compacting the capping and forcing disturbed stones and fines back into the matrix.’

While scuffing from booted feet disturbs the integrity of the surface, unprotected walking poles created far more track damage: ‘The tips are forced into the surface, creating holes and disturbance far greater than normal footfall. The damage is also more apparent on the sides  of the track where the surface is softer.’

Wilton calculated that a hiking pole with an unprotected tip creates a pressure of 3000kPa on the track surface, yet a pole fitted with a rubber cap creates just 70kPa. ‘It’s not possible to build a track with an aggregate surface that will withstand the penetrative pressures of an unprotected tip.’

By contrast, Wilton said rubber tips create a positive compacting effect on the surface.

Is there actually a chance I’ll get shot by a hunter?

“You’re probably more likely to hurt yourself getting out of the car at the trailhead,” says New Zealand Deerstalkers Association chief executive officer Gwyn Thurlow.

“Hunters are licensed, permitted and trained,” says Thurlow. “All hunters in New Zealand are police vetted and need to have a licence, hunting permit, have passed safety tests and have a responsibility to follow the Firearms Safety Code.”

Hunting isn’t allowed around public facilities or walking tracks. “Generally, trampers and hunters go into different parts of the bush. The government also closes areas to hunting at peak tramping times or in popular tramping locations to minimise any encounters.”

Nearly 200,000 people hunt in New Zealand each year, and there have been 41 recorded hunting fatalities between 2007 and 2016. Of these, only 54 per cent involved a firearm.

Thurlow advises trampers to talk to hunters about safety if they’re worried: “Open up the conversation. Share your plans so everyone knows where everyone is going to be.”

Hollow-fibre filters allow water to pass through but block larger microbiological threats

How do hollow-fibre water filters work?

Inside a hollow-fibre water filter, there are hundreds of tiny straw-like tubes filled with microscopic holes or pores.“Water is pushed through the wall of these semipermeable membranes, and the pores stop the larger microbiological threats getting through,” says Sandy McLean, who sells Platypus and MSR filters in New Zealand.

Depending on the nature of the hollow fibre membrane, threats such as viruses and bacteria are removed from the water and held in the wall of the fibre: “In essence,” says McLean, “hollow fibres are catching the bad guys and letting the good water transfer through.”

When uncompressed, down expands – or lofts – to trap pockets of air.

How long can I keep a down sleeping bag stuffed before it’s ruined?

Down clusters consist of filaments that grow from a central quill point and look like dandelion pods. The clusters expand or ‘loft’ to fill space and trap tiny pockets of air within the filaments to create thousands of insulating pockets.

But they’re very fragile, and once damaged they lose the ability to trap air.

Neil Stichbury from Outfitters NZ, distributor for Rab, says how a bag is stored can cause more damage than stuffing and removing a bag into a cram sac. “It’s prolonged compression that destroys the microscopic filaments on a cluster,” he says. “Ideally, after every use a bag should be dried, aired and placed into its mesh storage sac, ideally off the floor where air can circulate.”

Stichbury says the answer to ‘how long can I keep a down bag stuffed’ is: “Don’t! Try and preserve it as much as you can.”

High-top boots are likely to be sturdier and more stable than shoes.

Do high-top boots offer more support and stability than hiking shoes?

Gary Melhuish, the distributor of Salewa footwear, says it’s a misconception that hiking boots’ core purpose is providing extra ankle support.

“A key benefit is support,” he says, “but boots also provide ankle protection from rocks and abrasions and are more durable over rough ground. Generally, you can carry heavier loads while wearing a quality boot.”

He says a boot’s stability may be due to its overall build rather than provision of ankle support: “A quality outsole will have specific zones for overall grip, traction and braking.    Midsole materials could differ between a boot and a shoe. For example, hiking shoes may use soft cushioning compounds, while higher end boots may use a denser midsole which is less prone to compression and provides a more stable platform.”

Boot uppers are also more sturdy than those on shoes. “Leather used on boots is usually thicker and the use of a protective rubber rand is more extensive on boots. Hiking shoes are generally lighter and more flexible.

Are women’s sleeping bags really warmer than men’s?

“No,” says Neil Stitchbury. “But they often have a slightly different shape and the insulation is distributed in different places.”

He adds: “If I held them up and asked you to tell the difference, you would find it hard. Supposedly, women feel the cold in different places to men. A woman’s sleeping bag is likely to have more down in the foot and hip areas.”

Is thru-hiking bad for me?

Thru-hiking is the act of hiking a long-distance trail end-to-end continuously over several months. It’s an extended period of physical activity that impacts your body and health.

And, there’s a high chance of injury. Several studies show 40–60 per cent of hikers experience at least one injury during their hike; the most common are knee pain and blisters. Hiking’s prolonged and repetitive movement can induce repetitive stress injuries. However, the same studies show these injuries can be reduced with adequate planning, training and gear.

Thru-hikers are also prone to diarrhoea or gastrointestinal complaints, often caused by poor hygiene practices and lack of access to clean water.

In 2021 a study published by The Physiological Society showed how combining high periods of physical activity and consuming a nutrient-poor, calorically-dense diet for a long time alters important health markers, particularly arterial function, body composition and bone mineral density.

The findings suggest that large amounts of exercise do not compensate for a poor diet, may provide diminishing returns, and prove detrimental to physiological function.

However, it’s generally considered that the benefits of thru-hiking on physical fitness and mental health outweigh the potential drawbacks. Anticipating and managing injuries and illness while on the trail will lead to a healthier experience.

Is wool warmer than polypro?

It depends, says AgResearch textile technologist Stewart Collie: “Fundamentally, the smaller the diameter of the fibre (micron), the more warmth retention because there’s more surface area to help trap air, and it’s the trapped air that does the insulating. That’s an advantage to synthetics as they can be produced consistently at a set size.

“Polypro can be as fine as they want and merino wool used for socks is typically no finer than 18 micron.”

Based on that, you’d expect polypro to be warmer. But wool has a natural crimp, explains Collie: “This crimp (especially in merino) increases the space available for capturing air, which increases the heat retention,” he says.

Wool is also warmer in wetter conditions: “Wool actively produces heat when it absorbs moisture. Polypropylene has no ability to absorb moisture into the fibre. So in that sense, wool’s warmer.”

Canister stoves use a blend of propane, isobutane and butane gas to optimise vapour pressure.

How do butane, isobutane, propane and white gas differ?

Propane, isobutane and butane are classed as liquified petroleum gas (LPG) stored in pressurised gas canisters. White gas is classed as liquid fuel stored in pump-pressurised fuel bottles.

Most camping canister fuels use a blend of LPG gases to optimise ‘vapour pressure’: a fuel’s ability to vaporise, keeping the canister pressurised at a given temperature. This also ensures the mix’s stability in transportation and use.

“Specific gases have different performance and stability at different temperatures,” says Sandy McLean from Ampro Sales, the New Zealand distributor of MSR stoves. “Optimising the mix of gases burnt governs the performance of a stove in varying environments safely.”

A liquid fuel stove uses a pressurised fuel bottle to feed fuel to the burner head. “Because you’re controlling the pressure of the fuel flow to the stove, you’re in complete control of the stove’s performance regardless of external influences such as temperature,” says McLean.

Liquid fuel stoves work well in all environments and are cheaper to run but need little know-how.

“Canister stoves on the other hand are efficient and easy to use, but they don’t always work well in challenging conditions,” says McLean.

Why do I still sweat in a breathable raincoat?

Earth Sea Sky’s David Ellis says the breathable laminate used in a jacket and the clothes worn beneath it contribute to how well a jacket ‘breathes’.

A breathable laminate works on a pressure gradient. “It’s physics, driven by the difference in water vapour pressure. The greater the difference between the two, the better it’ll breathe. If there’s weather where water vapour pressure on the inside and outside are similar, the breathing will slow down.”

Walking up a hill with a pack in the rain, sweating profusely, increases pressure inside the jacket. The breathability of the garment is overloaded and condensation starts forming on the inside.

Ellis believes that what’s worn underneath is the largest contributing factor and this is where synthetics can outperform natural fibres. “Wool doesn’t feel wet or damp until it reaches 30 per cent moisture content, and it’ll still continue to absorb moisture well beyond that which will hinder breathability. There are better performing synthetic fabrics that will only absorb a maximum of three per cent of their weight in moisture which reduces the condensation within the jacket.”