Dreams Do Come True, by Katherine Grainger

London 2012 was not exactly short of emotional moments, but Katherine Grainger's victory with her partner Anna Watkins in the women's double sculls, roared to the finish at Eton Dorney by 30,000 partisan fans, ranks high in the list of Britain's Olympic achievements.

Watch the race again and you are struck by how easy and preordained their triumph seems – shooting straight into the lead from the start, they pulled away apparently effortlessly, crossing the line without any of their rivals having laid a glove on them.

Appearances can be deceptive, though, and Grainger's account of her extraordinary career reveals the years of blood, sweat, toil and tears that preceded that golden moment. Famously, the Scot had earned silver at each of the three previous Olympics, and at the age of 36 there was a sense of "now or never" going into the 2012 Games. But on all the evidence here, she is as strong mentally as she is physically.

She recalls that, "to check we were leaving no stone unturned", she and Watkins consulted a psychiatrist well before the action started, who concluded: "You're going to be just fine. I work with a lot of people who are preparing for the Olympics and of all of them I am least worried about you."

This is not one of those explosive, angst-ridden autobiographies along the lines of, say, Andre Agassi's Open. Grainger's private life remains a closed book, apart from a throwaway line to the effect that: "For some reason my commitment to rowing and studying has come easily; my ability to commit to long-term relationships has not had the same simplicity or success."

But her love affair with the water shines through, and her insider's view of the crises and characters involved in the tightly-knit world of British rowing are just as revelatory in their own way.

Grainger has plenty of career opportunities open to her when she finally quits rowing – when not in a boat, she has found time to amass BA, Master of Philosophy and PhD degrees in law – but, tantalisingly, she has not ruled out competing in the Rio Olympic Games in 2016. There may yet be more chapters to write in the sporting life of Dr Grainger.

Published in hardback by Andre Deutsch, £20