His ideas are set out in The Exercise Habit: Your Personal Road Map To Developing A Life-Long Exercise Commitment (Human Kinetics, pounds 11.95). The basic premise is that if you pick a form of exercise you aren't really suited to, you won't keep it up. No surprises there, but Dr Gavin aims to come up with a psychologically appropriate match. He kicks off with a few gung-ho chapters on the physical benefits of exercise, but pretty soon in come concepts such as mental health and self-esteem (is yours be low? It could be raised through working out). And then quizzes. To work out whether, deep inside, you are a rock climber or a ballet dancer, you have to work out your Vanity Quotient, your Sexuality Quiz score, whether you have (horrors) an Addictive Personality, whether you are an Age-a-Phobic, and whether you are really on a Search for Meaning.
And are you angry, assertive, competitive, sociable? The book follows the classic womens'-mag formula of listing assertions to which the would- be windsurfer must answer yes, no, maybe. "Even when I'm running errands, I make sure I look as good as I can." "I like being around people who turn me on physically." "I consider myself to be a playful person." "I feel completely at ease at parties and social gatherings." And there are a few killers in there. "I don't seem to say or do very much which is worthwhile" (sob). "I sometimes fear that as my life is ending I will realise I have completely missed its point" (whimper).
Once you have worked through all the quizzes and analysed your priorities, you can start making choices. Vain types will enjoy body-shaping and targeted calisthenics, but not cycling or golf. Sexy types could consider belly dancing, but won't care for football. The sociable will love folk dancing and hiking, but should avoid the loneliness of the long-distance runner. Aerobics won't help in the search for meaning, unlike t'ai chi and mountaineering. As for those with low self-esteem, avoid ballet, racquet sports and golf (too many opportunities to look hopeless) and go for "activities where you set the standards and just show up [his italics]" - swimming or stationary cycling would do.
Dr Gavin is realistic enough to recognise that even though you have the exercise that perfectly suits your personality, you may just be a lazy swine (no quiz available to test this), so he ends up with a pep-chapter on how to keep going. And, he says, don't be hostile to the mere notion of exercise. Find the method that chimes with your personality and you will enjoy yourself. (You will. Honest.) "There are so many different possibilities. Just get moving. Put on your Walkman and go for a walk to your favourite music." The gym, he emphasises, is not the only route. "If you go to a health club, you see people on stationary bikes and stairmasters with the most god-awful expressions on their faces - they are in misery. This is self-imposed masochism. Look at kids in the playground, they are running around having a great time. If you aren't having fun, why are you doing it?"