Who was chasing him?
We need air to function. If we are to function when doing exercise, we need more air. This seems obvious, so it is strange to discover that, even among those who might claim to have no breathing difficulties, exercise shrinks the airways. We call this exercise-induced asthma, but while the label is in common usage, this is not a correct description: we should really call this effect a bronchospasm (because the airway constricts) or thermally-induced asthma. Cold, dry air breathed in needs to be warmed and made wetter (see Aristotle’s thoughts on this, described in ‘All his heart was cold’). When we are working hard and therefore need more air, this moves the air-conditioning process further down the lower airway. In those who suffer from this condition, exercise causes the airway to narrow; a narrower passage makes it harder to breathe; and in effect, our bodies are preserving the quality of air, in preference to supplying the quantity we might like.
We may feel that the airway has become dry, but the research says this is not true; what we feel is the airway working hard to deliver sufficient evaporation so as to wet the air sufficiently. While this is all going on, of course, the rest of our body has become both warmer and (subsequently) wetter, this time for the purposes of cooling us down. Swimming is a sport at which asthmatics can excel, because the warm moist air doesn’t trigger an attack. As the number of pools around the country falls, so participation has dropped (by 10% since 2008, despite the continued success of British international athletes in this discipline). For asthmatic swimmers, however, swimming in a sheltered, warm, indoor environment (polluting the air further as they drive long distances to their nearest pool) may be part of a trade-off. The warm, moist air is easier to breath, but these swimmers will also be inhaling large amounts of chlorine. Moreover, indoor swimming (chlorine and all) may be their only option, as swimming outside (free, sea or ‘wild’ swimming) takes place in an environment where the air is unchlorinated, but does not have the required warmth and moisture. This is why breathing can be so challenging for other athletes if their sport requires them to exercise in very cold environments; for example, cross-country skiers may need to wear heat exchangers to compensate for the extremely low temperature of the inhaled air.
Among the physically active, exercise-induced asthma is a recognised problem. Some runners, for example, sound as though they are in respiratory distress: they (we) are called ‘breathers’. If you watch a race on television, you rarely see (or hear) how hard people are working until the inevitable out-of-breath post-race interview; watch a race in the flesh and you will see (and hear) just how very hard the runners are working. You might notice that a greater proportion of the older runners are breathing hard. This is not only because old lungs don’t work so well, but because long-time runners have built-in expectations of performance, so sometimes push the envelope harder than they mean to.
David is known as a ‘breather’ when racing. In race conditions, he sounds in serious discomfort and has been shouted at to either slow down or accept medical attention. This can have several effects upon the competition: other runners can hear him coming and so have no need to look around; some are slowed down by the distraction, while others speed up. On rare occasions, David can suppress the noise briefly and use this to further discombobulate other runners, perhaps creeping up on the competition in a more comfortable (and therefore quieter) downhill section. After fifty years of running, David knows that if he is not breathing hard, he’s not racing, and the noise may serve as a measure to others of ‘what racing sounds like’. When David was teaching sport (see his essay ‘Sports Day‘ for a description of attempting to do so in China), many took his laboured breathing as a sign of the effort expected of them, and subsequently pushed themselves to a similar point. Too many people compete well inside their comfort zone, becoming inhibited by the sound (and volume?) of their own breathing, among other things, rather than using the sound as an indicator of how hard they are working. People who do not regularly exert themselves and push their lungs hard may, of course, have no idea whether their lungs are functioning normally, or where their own physical limits lie. They may, therefore, miss the early signs of increased breathlessness; if and when they are found to require medical attention, it may be too late. Thus, an illness might silently creep up on an unsuspecting person, and late presentation is a well-known problem in diagnosing respiratory conditions.
David’s time in China included living in extremely polluted cities (to be explored in a future post on air pollution in Beijing); moreover, despite the moist, warm air in much of the country, China does not have the ‘jogging culture’ of the UK, where runners are a common sight at all hours of the day. David’s victories in the relevant age category of various organised races across China (see, for example, his essay ‘The City Wall Race‘) resulted in prizes of assorted white goods, a new pair of running shoes, and more than one appearance on television, so unusual is it in Asia to see a sixty-year-old man running about in public of his own free will, pushing his body as hard as it will go. On training runs, local Chinese often wondered what on earth he was doing, baffled by both the fact that David was running at all and the rate at which he was going. Who was chasing him? David was, of course, not the chased, but the chaser: of a better time, and better long-term lung function.
 We might also think of the ancient four humours theory of medicine, in which each humour (blood, phlegm, yellow bile and black bile) was associated with various personal and physical qualities. Warmth and moisture were associated with blood, the humour also thought to relate to air in some way. Here we find the familiar ideas of balance and excess seen in so many ancient theories of medicine, including Chinese medicine (for example, the interdependence of Zu Fang networks in the body under the Wu Xing system).
 Adrian Moorhouse (100m breaststroke gold, Seoul Olympics) and Rebecca Adlington (four medals, Beijing and London Olympics) are good examples of asthmatic swimmers who found that the warmth and moistness of the air allowed them to overcome their condition.
 See, for example, Bernard et al., ‘Lung hyperpermeability and asthma prevelance in schoolchildren: unexpected associations with the attendance at indoor chlorinated swimming pools’, Occupation and Environmental Medicine 2003. These points re. chlorinated air, cross-country skiing and heat exchangers (and the paper on chlorinated air) were supplied by Simon Evans, one of David’s former students, who ‘remember[s] well Mr. Scoins panting’, and for which both authors are grateful.