I, too, have been diagnosed with EIA, and have had episodes of coughing after exercising. Both riding and snowshoeing at atitude in the winter. My allergist told me it was "delayed onset EIA". I googled it and this is what I found.


The manifestations of EIA offer some insight into possible causative mechanisms. In persons who have EIA, the first 3-5 minutes of physical activity usually have normal effects. When the physical activity stops, lung function decreases (as measured by PEFR or forced expiratory volume in one second, FEV1) within the 5-10 minutes after the activity stops; if physical activity resumes, symptoms begin to manifest during the first 5-10 minutes of resumed activity. This decrease in pulmonary function is usually accompanied by symptoms and persists for 15-40 minutes; pulmonary function then normalizes, and symptoms resolve (Figure 1).3 Decreases in FEV1 or PEFR often range from 20% to 50%. This early-phase response is the most common manifestation of EIA. In a few individuals, a late-phase response related more to inflammatory changes may occur within 3-10 hours after physical activity stops. The degree of late-phase decrease in pulmonary function is usually greater and more prolonged than in the early-phase response. A refractory period ranging from 40 minutes to 2 hours follows an episode of EIA; during this refractory period, it is difficult to recreate symptoms.

Multiple factors appear to affect frequency and severity of the change in pulmonary function and symptoms. To study possible pathologic pathways by which symptoms are produced, two primary models of asthma have been used: induction of symptoms by exercise and induction of symptoms by isocapnic hyperventilation. Use of these two models has led to the following information:

The greater the person's baseline level of bronchial hyperreactivity as measured by histamine or methacholine challenge, the greater the likelihood of EIA developing or worsening.
The greater the minute ventilation (with all other factors controlled), the greater the intensity and duration of EIA up to a maximum of two thirds of the individual's maximum working capacity.4
The less humid the inspired air, the greater the trigger for EIA (Figure 2).5-8
The cooler the air, the greater the trigger for EIA (Figure 2).5-8
Exposure to airborne allergens worsens EIA.
Certain air pollutants (eg, ozone) may worsen EIA

Here is the entire article, http://xnet.kp.org/permanentejournal/fall99pj/eia.html

I use my inhaler 20 minutes before I exercise and if I feel like I need it during exercise. I've had more symptoms snowshoeing and hiking than I do on the bike. If I do get coughing after I exercise I use my inhaler and the coughing stops immediately.

BTW, I don't remember that any of these episodes were after very strenous bike rides, it did happen after 2 long 4 hrs+ bike rides. I'm thinking that it was something like air pollution, dry air, pollen or humidity that brought them on.