When I picked this book up, I already loved it — or at least I loved the idea of it: heroic sporting underdogs, a new coach with nothing in common with his players, and the forging of an indestructible bond of comradeship, all topped off by success on the world stage.

But I felt trepidation too. Books about sporting greatness often descend into a gruelling slog through humdrum match reportage, reheated banter and details of contract negotiations, game plans, diet plans and training. I needn’t have worried. In this account of three years in charge of the Fiji sevens rugby squad, Ben Ryan and his writing collaborator Tom Fordyce get the mix just right.

Ryan — a long-serving former England sevens head coach — abandoned Teddington in west London for Suva in 2013; but on one level the geography of Sevens Heaven is irrelevant. What we are reading is more like a piece of time-travel: a coach from the era of hyper-professionalism, of bluetoothing personalised video footage to players’ complimentary iPads, finds himself back in the amateur era. Here, everything is still make-do-and-mend.

On another level, though, geography is cental to the book. Ryan encounters Fijian time (approximate), finances (non-existent), politics (brutal), society (nepotistic) and superstition (extensive). Other coaches might have beaten a retreat to their hotel for the duration, holing up with laptop and playbooks to craft instructions for delivery at closed-door training sessions.

Instead, Ryan — short, pale, ginger-haired and freckly (he could not possibly look more un-Fijian) — opts for total immersion in a country that is both ‘a puzzle and a charm’. To connect with his players, to get inside their hearts and minds, he ventures into the hills, over the waves and out to the villages. He becomes ‘coach, politician, anthropologist and agony aunt’.

Family life often holds the key to these men’s states of mind. One player, Jerry Tuwai, wrote ‘knife’ on the bottom of his left boot and ‘fork’ on the bottom of the right. Rugby was his route to putting food on the table for his struggling extended family. Ryan gets to know uncles, wives, foster mothers, girlfriends, all in the cause of smoothing the path to the Olympic sevens glory that the nation craved. He seems to form stronger bonds with the vulnerable yet indomitable men of his Fiji squad than with the elite English players he used to coach.

Yes, there are diets and training routines to read about, but even these are more interesting than usual, whether it’s weaning gigantic Fijians off their predilection for sugary tea or running sessions on the alpine sand dunes of Sigatoka, which end with bodies ‘strewn around like they’d been dropped from the skies’.

But Sevens Heaven is not one uninterrupted, uplifting, high-fiving voyage of discovery. Cyclone Winston visits terrible destruction on the islands. Ryan broods in flashbacks about the fate of Noel, his best friend as a boy, who drifted away from him into a life of crime. He doesn’t try to hide his low opinion of his former employers at the RFU, or rival coaches who irritate him. We also become witnesses to the disintegration of his marriage.

Ultimately, though, the good vibes win out. In 2016, Fiji beat Great Britain in the Rio final, winning the country’s first Olympic medal. A bunch of humble, likeable, friendly men come first. How about that?