Jack Harper-Tarr always signed off letters and emails with "yours in sport". The phrase encapsulated the Cumbria PE teacher: his love for his subject, his belief in the good it could do pupils, and his indefatigable efforts to ensure they had opportunities to practise it.
He was born David Arnold Harper-Tarr in Nottingham in August 1938. With the outbreak of World War Two, he was evacuated to his grandmother's house. Then, when his father was demobbed, the family settled in an Oxfordshire village.
When David introduced himself at school, he was greeted by an audible groan from the rest of the class. "You'll have to come up with another name," the teacher told him. "We already have six Davids in this class." Put on the spot, he opted for Jack. It was the name by which everyone apart from his parents knew him from then on.
Teenage Jack had planned to enlist in the army. But his ambitions changed when an A-level PE teacher suggested that he consider a career in teaching instead. After completing his training, he submitted his first and only job application, to Caldew School, a new secondary modern in Cumbria.
Here, the young Mr Harper-Tarr's open-mindedness made an immediate impression. He refused to judge any pupil on reputation or family background alone: with him, everyone started with a clean slate.
He also resolved that school sport should not be limited to conventional team games. Instead, he introduced basketball and volleyball, as well as bringing in bikes and tracks when the BMX craze hit in the 1980s. He had a particular fondness for athletics, and would ensure that pupils had access to the full range: shot-put, javelin and discus. And when a new sports hall was built, he insisted on a climbing wall around the outside.
Similarly bucking convention, he pushed for mixed-sex sports teams. There was no reason, he believed, that girls should miss out on competitive sport purely because there was not enough interest for a girls-only team.
After matches, Mr Harper-Tarr would enlist the help of Jean Duckworth, Caldew's domestic-science teacher, to run team strips through the school washing machines. A friendship blossomed over the spin cycle; Mr Harper-Tarr proposed in 1966, just after England won the World Cup.
By the end of the 1960s he had been appointed head of PE. And in the late 1970s the school supported him through a BEd in education and psychology at Lancaster University. The choice of subject was inspired by his conviction that sports lessons had an impact on pupil performance and behaviour across the curriculum.
Though quietly spoken, he was nobody's yes-man, and knew how to make his point of view heard. When, for example, he wanted something done at school, he would make two smaller requests to the headteacher first. The head would inevitably agree to all his demands without even hearing the third.
He believed strongly that his school should provide sports facilities for the entire community. Indeed, he was eager to work with the tiny rural primaries whose pupils would one day attend Caldew.
Inevitably, given the school's location, he found himself regularly raising money for lengthy journeys to sports fixtures. And so he variously set up a school tuckshop, sold refreshments at school discos, and established a lunchtime music club where pupils could listen to records for a token contribution.
Such skills proved handy after retirement in 1998. When Caldew celebrated its 40th anniversary, it was Mr Harper-Tarr who organised a disco and buffet. Ten years later, he also oversaw the 50th birthday party.
Almost immediately after retirement, he was contacted by the local authority and asked if he would work with nearby primaries. From there, he went on to train would-be primary teachers at Lancaster University in how to deliver PE lessons. And he worked part-time at Cumbria's William Howard School. Finally, just before his 71st birthday, he decided it was time to quit for good.
Or, at any rate, to get as close to quitting as he was capable. He remained a judge at World Masters, the international athletics meetings for the over-35s. And he continued to grow vegetables - beetroot, onions, beans - in his garden at home.
In April this year, he was sitting down to dinner when he suddenly felt unwell. He suffered two consecutive heart attacks; within five hours, he was dead.
Jack Harper-Tarr is survived by his wife, his daughters, Kerry and Lindsey, and his four grandchildren.