KEY POINTS:
As we stood breathlessly congratulating ourselves on finally reaching the plateau on which Tengboche Monastery sits - reasonable enough after climbing a rough stone staircase 620m high - a porter came into view on the track below.
He was moving a bit faster than we had managed on the steep, stony, slippery surface. Instead of our fancy trekking boots with ankle supports and special soles, he was wearing plastic sandals.
He was carrying on his back - the weight supported by a cloth band across his forehead - a mountainous load, including a plastic container of kerosene, a large cardboard box labelled as containing a television set, several large metal cooking pots, and a couple of cans of paint.
When he reached the top, where we stood, he rested his load on the head of the chunky wooden stick all porters carry and waited a few minutes, not puffing as we were but eyes glazed in contemplation, then set off again, skipping over the rocky surface at a brisk pace.
Suddenly our achievement in getting here didn't seem so impressive.
In this part of Nepal, where there are no roads, everything must be carried along the narrow tracks and if dzopkos - shaggy yak-cow crossbreeds - are the local Mack trucks, then porters are the Commer vans.
With the Nepalese economy in a sad state after years of political strife - which seems finally to have come to an end - working as a porter is a crucial source of income for huge numbers of Nepalese.
Most porters were young men earning money for families in remote mountain villages but they range from teenage boys financing further education in Kathmandu to young women with aged parents to support and wrinkled men and women prematurely aged by the harsh life but with no other way of feeding themselves.
The size of their loads varies, but probably averages around 30kg and includes an extraordinary array of goods. One I followed was carrying a basket filled with huge lumps of meat, a crudely butchered dzopko, by the look of it.
In the middle of the cluster of houses the porter sat his basket on a stone shelf, locals gathered round, cut off chunks of meat and handed over their money, after which he lifted his load and continued up the track.
Another had a basket piled high with iron pots, pans and assorted utensils.
Walking alongside him a young man was loaded with cartons of beer and soft drinks for the guesthouses and shops lining our trekking route.
Many carried huge plastic jerrycans of kerosene to fuel the stoves and lamps in an area where electricity is rare.
But, in a sign of modernisation, one group of 20 porters staggered under the weight of a length of cable being taken to one of the small hydro-electric projects being developed in the mountains.
Probably the most common load was of kit bags being carried up the track, mostly four at a time, so trekkers like us could have an easy time.
Work as a trekking porter is keenly sought after - the planes that fly trekkers into Lukla Airport are always met by huge crowds of locals hoping for a job - but it is a difficult, dangerous and poorly paid existence.
The website of the International Porter Protection Group (IPPG), formed in 1997 to campaign for the interests of porters around the world, has some horrific tales of the conditions under which they work.
Even today, most of the 300 trekking companies operating in Nepal require porters to provide their own protective clothing, shelter and cooking equipment - which means they are often not properly clad and have to sleep in caves or under bushes - and all for NPR300 (about $5) and a cup of rice a day.
The trekking company I was with, World Expeditions (WE), is not one of those companies. It is acknowledged by IPPG as having "significantly raised the standard of porter care by large companies and setting important industry standards".
World Expeditions provides porters with weatherproof clothing and boots, a communal tent to sleep in, plus mattresses and sleeping bags, and cooking equipment - kerosene fuel to alleviate the use of wood - and food.
Our expedition leader, Ang Tshering Sherpa, said because of this, the company was regarded as "the best" to work for and other guides and porters, many of whom spoke reasonable English, echoed that view.
But all this good work has a price. Sue Badyari, chief executive of the company, estimates that employing trekking porters in these conditions adds perhaps $120 a person to the cost of an expedition. "Sustainable travel comes at a cost."
It would be nice to think that New Zealanders trekking in Nepal would be happy to meet that extra cost to know that their expedition porters were being properly cared for.
The IPPG recommends anyone thinking of going trekking should first seek an answer to a simple question, "Does the company follow IPPG's five guidelines on porter safety?" It doesn't seem too much to ask.
