Training this winter

Only these suggestions from the article I linked (which you've probably read by now):

Non-pharmacological management includes the following:

• Warm-up. It has been known for years that many asthmatics experience what is known as a ‘refractory period’ following a 10-15 minute bout of moderate intensity exercise (50-60% maximum heart rate), or ‘warm-up’. Refractoriness means that for up to two hours after the warm-up, asthmatics can exercise (even intensely) and not experience EIA (8). The precise mechanisms for refractoriness remain unknown, but it offers a simple and easily-implemented management technique for those in whom it works;
  
• Dietary modification. Although the relationship between food tolerance and asthma has been studied for many years, and positive relationships have been identified, the effects of dietary modification on EIA has only recently been examined (9).
  
  

One of the earliest dietary components linked to asthma was salt. Recent evidence suggests that restricting salt intake reduces the severity of the post-exercise decline in lung function in people with asthma after just one week(10). At the start of the study, the subject’s FEV1 declined by 27% post-exercise, but after one week on a diet restricted to 1,500mg/day of sodium, the post- exercise fall in FEV1 was only 9%.
By contrast, a high sodium diet has been found to exacerbate post-exercise falls in FEV1(11). Studies examining the relative contributions of sodium and chloride to the severity of EIA suggest that both are involved(9). The recommended daily allowance for sodium for reducing hypertension is 2,400mg/day, which is considerably higher than the effective range for EIA attenuation (1,000-1,800mg/day). The restriction of salt intake therefore offers a simple non-pharmacological approach to the management of EIA.
Fish oils have also been studied for their potential role in alleviating EIA. These are rich sources of omega-3 polyunsaturated fatty acids (PUFAs), which are thought to damp down inflammatory responses. The link between fish oils and asthma was based on the low prevalence of asthma in Eskimo populations, which have high intakes of fish oils(9).
A recent study on the effects of three weeks’ supplementation with fish oil capsules on EIA in élite athletes produced some encouraging findings. The researchers compared a normal diet with a placebo diet and a fish oil-supplemented diet and found that fish oil supplementation reduced the post-exercise fall in FEV1 from 17% on the normal diet to just 3%(12). These preliminary data suggest that fish oil supplementation may offer another non-pharmacological approach to management of EIA.
Free radicals and the benefits of antioxidant vitamins

The damaging role of free radicals and the protective effects of antioxidants in sport is currently receiving a great deal of attention. Since inflammatory cells produce oxidants and asthma is an inflammatory disease, the role of antioxidants in EIA has naturally been investigated. The principle antioxidant vitamins are C and E, and recent studies have demonstrated beneficial effects of both.
Preliminary data from one study suggests that three weeks’ supplementation with a combination of vitamin C (500 mg/day) and vitamin E (33 IU/day) can reduce the post-exercise fall in FEV1 by 10%(13). An earlier study examining the effect of vitamin C (500mg) alone, with a much shorter supplementation period of just 90 minutes, showed a halving of the post-exercise fall in FEV1, from 20% to 10%(14).
Thus, it appears that antioxidant vitamins also offer some protection from EIA, although not all subjects appear to respond to supplementation(15), and the differential effects of vitamins C and E are unknown, as is the optimum supplementation regimen.
Because of its well-known ergogenic effects, caffeine supplementation has been used by athletes for many years. This has led the IOC to establish a limit on caffeine consumption, which is defined by its concentration in urine – no greater than 12 mg/ml.
Caffeine as a bronchodilator

It has been known for many years that caffeine is a bronchodilator(16), and two studies have specifically examined the effects of caffeine on EIA. In one, researchers observed a reduction in the severity of the post-exercise fall in FEV1 from 24% to just 10% after subjects consumed 7mg per kg of body mass of caffeine (~50mg, or three strong cups of coffee) two hours before an exercise challenge(17). In another, using an EVH test and a stronger caffeine dose of 10 mg/kg, researchers observed a similar effect on bronchoconstriction, with the fall in FEV1 reduced from 17% to 7%(18).
However, lower doses of caffeine (3.5 to 5 mg/kg) have not been shown to have a significant influence on EIA. And, unfortunately for competitive athletes, the doses which do seem to offer protection would probably give rise to urine concentrations of caffeine in excess of the IOC doping limit.
Since, additionally, caffeine is also a diuretic, its use for the management of EIA is not recommended, especially as other dietary modifications are neither banned by the IOC nor associated with any known negative side effects.
The principal symptom of bronchoconstriction is an increased sense of respiratory effort, or breathlessness. There is a strong relationship between the strength of the inspiratory muscles and the sense of respiratory effort(19), and this has been demonstrated directly in people with asthma.
One research group has conducted a number of studies examining the influence of specific inspiratory muscle resistance training (IMT) on symptoms, respiratory effort and consumption of medication in asthmatics. And they have come up with some impressive results, with subjects showing huge reductions in their consumption of both beta2-agonists and their ratings of breathlessness(20, 21). Unfortunately, no studies have yet examined the influence of IMT on EIA per se, and it is very unlikely that it has a direct effect on the severity of bronchoconstriction.
Nevertheless, it seems that IMT alleviates the principal symptom of bronchoconstriction (breathlessness). In addition, recent studies on non-asthmatics have shown that IMT is ergogenic (see PP171, Oct 2002) and also reduces respiratory and whole body effort sensations. Improvements in time trial performance and reductions in inspiratory muscle fatigue have been demonstrated by well controlled studies(22-24).
For athletes with asthma (for whom the work of breathing may be higher), IMT may offer even greater improvements in performance as well as symptom control. However, further research is needed to fully understand the beneficial effects of IMT in asthma.
In summary, the first step in the effective management of EIA is early recognition, and any athlete who repeatedly experiences asthma-like symptoms should seek a definitive diagnosis. For those who do have EIA, there are a number of management options, including dietary and training manipulations, as well as drugs.
For competitive athletes whose asthma falls short of the IOC criteria for pharmacological management, the non-pharmacological approaches outlined in this article offer the only means of minimising the negative impact of mild EIA on their ability to fulfil their sporting potential.
Alison McConnell