By that token, the 29-year-old Texan who this summer became the first man to win Olympic 200 and 400 metres titles is, well, mighty strong. No one has beaten him over one lap since 1989, and his achievement in lowering his own 200m world record to 19.32sec in Atlanta was one of the all-time great Olympic performances.
Johnson is an exceptional athlete, and his book - an exhaustive self- scrutiny - gives a real insight into what his endeavours have required.
Athletic performances are only a part of it. Here is a contender for the world record in positive thinking, a man whose victories have been forged within before he steps on to the track.
There are passing observations of others, and some devastating criticism of that other pre-eminent US athlete, Carl Lewis. But all this is a matter of a runner's peripheral vision as Johnson devotes himself to the implied challenge of the book's title - Slaying The Dragon (Piatkus, pounds 10.99).
"For each of us," he writes, "that dragon is the thing closest to the centre of our lives. It is our core, our ambition, and our joy. For me, it is the perfect race."
The key words for Johnson in fashioning his unmatched career are: consistency, order, self-discipline. Johnson's coach, Clyde Hart, tells the story of how he once discovered his charge training in a rainstorm when every other athlete had taken the day off. "You never know when you might have to run in the rain," Johnson replied.
When he was studying "finite math" at Baylor University in 1987, and having grave difficulty in mastering it, he evaluated his position and recognised the fact that he was better at understanding binomial coefficients at 6am. "Finally," he said, "I did something very difficult for a college student. I began going to bed at 8pm." The style is the man.
What gives Johnson's narrative particular force is the fact that he has triumphed after traumatic experiences in previous Olympic years. In 1988, injury prevented him qualifying, and in 1992 his position as clear favourite for the 200 metres gold was calamitously undermined by the effects of food poisoning.
"I wondered if I would be one of those athletes who is at the top of his sport but never wins the biggest event," he writes. "Like a talented boxer who blows his only title shot or a great baseball player who never makes it to the World Series."
In the great tradition of all self-help manuals, Johnson explains how he turned such setbacks to his advantage in using them as a motivational tool. But the earnestness which this book has in common with many another American self-help manual is tempered by little flashes of wry humour in the narrative.
"I hope to get married and start a family, although these goals need a different kind of planning... for instance, this is not a goal that will work: "Memo to self: fall in love, April 1998."
There are some things in this life that even Michael Johnson cannot control.
The subjects of Richard and Fiona Bailey's The Road To Glory (Quiller Press, pounds 25) also have things in their life which they cannot control in the form of disabilities. But this photo-essay, subtitled "Portraits of Britain's Paralympians", is a book not about disability, but competitiveness.
"When I hear commentators say it is lovely that disabled people can take part in sport, and that they do it for fun, I think about all the times I get up at 5am, ride up a hill for five miles non-stop and almost collapse at the top from exhaustion," comments the cyclist Robert Allen. "The word fun is not on my mind. Winning is."
Black and white photos of a range of sports from athletics to powerlifting give graphic evidence that Allen's philosophy is a shared one.
The Runner's Handbook (Penguin, pounds 9.99), by Bob Glover, is now designated as "all new" after updating this year. But it is packed with down-to-earth advice for the ordinary runner, from choosing a time for exercise or a pair of shoes to devising strategies to deal with aggressive dogs or people encountered en route. Humorous and informative - a good combination.Reuse content