Written by Hans Degens (Manchester Metropolitan University), Tony Sargeant (retired), Di Newham (King’s College London), Jamie McPhee (Manchester Metropolitan University) and Malcolm Jackson (University of Liverpool).

https://doi.org/10.36866/pn.118.51

David was elected a Member of The Physiological Society in 1978, was a Distributing Editor for The Journal of Physiology (1993 – 1999), and was involved in setting up the Human Physiology Interest Group, now the Human, Environmental, and Exercise Physiology Theme. He graduated in 1965 from Birmingham University in Medical Biochemistry and then took up an MRC training studentship at the Institute of Psychiatry in London, first with Richard Rodnight and then as a research assistant to Henry McIlwain. In 1971, he became a Research Fellow at the Royal Postgraduate Medical School, Hammersmith Hospital, with Richard Edwards and David Hill. David Jones, with Pat Merton and later Brenda Bigland- Ritchie, were the first to describe “high-frequency” and later also “low-frequency” fatigue, and among the first to use electrical stimulation to differentiate between central and peripheral fatigue.

In 1976, at the Department of Medicine, UCH, working with Malcolm Jackson on zinc absorption, they were amongst the first to use stable isotopes in humans. With Di Newham he showed that delayed onset muscle soreness (DOMS) is not the result of muscle fibre damage, but probably due to connective tissue changes. With Joan Round he studied muscle growth during childhood and adolescence. With Olga Rutherford he was one of the first to use ultrasound and CT to study training-induced changes in muscle architecture.

Through teaching on the MSc course about muscles run by Roger Woledge, Nancy Curtin and Sally Page at UCL, David first worked with Tony Sargeant leading to a long-term collaboration with many Dutch colleagues, among them Arnold de Haan. They showed that fatigue is not only associated with loss of strength but also slowing. Experiments at UCH with magnetic resonance spectroscopy demonstrated that the loss of function with fatigue is not necessarily caused by the accumulation of lactate or H+.

In 1993, he became Head of the School of Sport and Exercise Sciences at Birmingham University, where he found that a major factor limiting prolonged exercise is an increase in both core and skin temperature. With Alison McConnell and Lee Romer he showed the value of respiratory muscle training. Most intriguing was the observation that directly infusing glucose had no beneficial effect, while rinsing the mouth with carbohydrates did improve performance. Using fMRI, they found that carbohydrates influenced, via sensors in the mouth, parts of the brain associated with motivation.

In 2004, he was appointed at Manchester Metropolitan University, where, with Hans Degens, he found that accumulation of inorganic phosphate depresses force production and that low levels of calcium may contribute to slowing of the muscle fibre shortening. At Manchester he also studied the variable response of individuals to both strength and endurance training. His work on ageing expanded into a large European survey in collaboration with Marco Narici and Jamie McPhee, which led to a study of the motor unit changes with ageing. David continued to be active right up until his premature death, making major contributions to research with collaborators in Lithuania, and in Thailand with his wife Chulee Ubolsakka-Jones on strategies to improve respiratory function in a range of patient groups.

His teaching was filled with humour and incredible patience. I myself (Hans Degens) must have caused him at times exasperations when he tried explaining to me the intricacies of cross-bridge kinetics, not once, but repeatedly. His saying that “old men are like young women” filled us with surprise and laughter, but he clarified he was not talking about beauty, but rather about the fact that the muscle mass in old men resembles that of young women. David was a generous man, a man with a listening ear, who was always happy to lend support where he could. We have lost a great friend.

David was predeceased by his first wife in 1993. He is survived by his son Luke from that marriage and by his second wife Chulee.