Here's an account of an old man going on a marauding expedition that involved an 80-mile round trip through a desert.

The source is Travel & Adventure in South-East Africa by Frederick Courtney Selous.

The Matabele had been raiding the Batauwani. The Matabele, as some readers will know, were an offshoot of the Zulus and an extremely militarized society that pretty much destroyed and depopulated areas of south east Africa, walking through peaceful agricultural societies with consummate ease.

What's interesting here is that one at least of a raiding party described by Selous was of a fairly advanced age - in his seventies. The Matabele mode of life evidently enabled this man to stay in pretty good condition till a fairly advanced age.

The Matabele lived, like the Zulus, on the products of their herds and fields. They would also have hunted some wild game, and they would have seized cattle and other foods on raids, as well as demanding tribute from subject peoples (Mashonas/Mashunas).

Now I know that obesity was known among the Zulus. It was something of a red rag to their most most famous king (and founder), Shaka, who equated it with over-eating and laziness. On one occasion Shaka made his whole court go on a run that lasted for some days, which must have damn-near killed some retainers (and did some). However, to drop out would have been certain death, since Shaka's slayers accompanied and had instructions to kill anyone who fell out.

I suspect the basic diet was pretty good. I recall an account of Shaka's breakfasting on grilled meat, spinach, and porridge with honey, with milk and beer to drink. I think the porridge was probably made with mealies (maize), and I doubt maize ever did most people much harm - unless it made up too much of the diet. Many Plains Indians seemed to have lived on almost nothing but buffalo flesh and maize, and to quote the painter George Catlin:

During my Ethnographic labours amongst those wild people I have visited 150 Tribes, containing more than two millions of souls; and therefore have had, in all probability, more extensive opportunities than any other man living, of examining their sanitary system ... Amongst two millions of these wild people whom I have visited, I never saw or heard of a Hunch-back (crooked spine), though my inquiries were made in every Tribe; nor did I ever see an Idiot or Lunatic amongst them, though I heard of some three or four, during my travels, and perhaps of as many Deaf and Dumb. ...
Anyway, as I say, the basic diet of the Zulus and Matabele sounds sound to me. I suspect the problem could be that richer and more powerful individuals sometimes indulged too much in the beer.

So here's the account:

I have often noticed men of a very advanced age taking part in the most arduous raids made by the Matabili on the surrounding tribes, and I will adduce one very remarkable instance, which seems to show that savages sometimes retain their vigour for a very long period of time ...