Underwood was always impressed by physical achievement through determination. He was an early practitioner in Britain of "sport science" - the study of the mental skills of athletes. This year he had been working with a member of the British Mogul ski-team, Tim Dudgeon, preparing for the 1998 winter Olympics in Japan and had just written two new self-help sport psychology books, one for rugby players (Mental Skills Training for Rugby, 1996), the other for orienteers (Mental Skills Training for Orienteering, 1997, co-written with Steve Bird), which were the beginning of a planned series.
His first book, The Physical Education Curriculum in the Secondary School: planning and implementation, was published in 1983, followed by Teaching and Learning in Physical Education: a social psychological perspective, in 1988.
Underwood was born in 1933 in Lincolnshire, and as a boy was athletic and ambitious. He played rugby at Deacon's School, Peterborough, and was selected for Northampton county under-16 rugby team. After National Service in the Royal Army Service Corps he became a captain in the Territorial Army.
Between 1952 and 1954 he studied Physical Education at King Alfred's College, Winchester, and then at Loughborough College. In 1955 he was appointed assistant games master at Harrow County Boys' School. He took groups of Harrow County boys on rugby tours of France, packed into a minibus with tents, food, rugger kit and enthusiasm.
In 1963 he was one of the first students on the Advanced Course in Physical Education at Carnegie College, Leeds, and received his first lectureship there in 1964, aged 32. He was a natural leader and gifted teacher and his interest in the academic aspect of sport and education developed as knowledge of athletic performance advanced into areas of sociology and psychology. It was accepted at this time that in order to excel in any sport peak physical fitness was essential. What began to emerge was the realisation that the difference between winning and coming fourth was in the mind of the athlete; a psychological advantage was necessary.
In 1966 Underwood joined the staff at Nonington College of Physical Education in Kent. He was promoted to Principal Lecturer and then to Head of the large Department of Movement Studies. This degree course trained PE specialists and prospective sport scientists. Underwood became one of the few academic and practising sport scientists in the country.
Whilst at Nonington he received an MA from University College London and developed his interests in curriculum planning, skill acquisition and the performance of top athletes. Among his colleagues was the gymnast and international swimmer John Wright, a longtime friend.
After the government closure of Nonington in 1987, which Underwood handled with a fighting grace, he moved to the Sport Science Department at Christ Church College, Canterbury, developing and teaching the Sport Psychology area of the undergraduate course. He received his doctorate in 1989 and was made an Honorary Fellow of the University of Kent.
In the course of his career, Underwood worked in association with many professional organisations including the Lawn Tennis Association, the Rugby Football Union, the Sports Council and the under-16 Kent cricket team.
Gordon Underwood's passion for sport never diminished. He continued playing rugby, he ran a marathon; on his 60th birthday he descended the Olympic bob-sleigh run in La Plagne. In recent years he loved nothing better than a 10-mile bike ride in the woods, followed by an England rugby international on television. Four days before he died, suddenly and unexpectedly, he was in the French Alps with his son, skiing black runs at over 3,200 metres.
Gordon Leonard Underwood, sport psychologist: born Market Deeping, Lincolnshire 8 January 1933; Senior Lecturer, then Principal Lecturer and Head of the Department of Movement Studies, Nonington College of Physical Education 1966-87; Senior Lecturer in Sport Science, Christ Church College, Canterbury 1987-97; consultant lecturer, Goldsmiths' College, London 1994-97; married 1954 Beryl Adamson (one son, one daughter); died Barham, Kent 11 March 1997.