A Runner's Year of Pace Checks

Running Through Pollen Season

1Kofi Asante, a sixth grader, runs with the Hollins Park running club, which meets in the city park all year long. Kofi has asthma. His doctor says that many people with asthma run and play sports when their asthma is well controlled, and she gave him a peak flow meter to help. It is a small tube that he blows into as hard and fast as he can. It measures how fast air leaves his lungs, in liters per minute (L/min). Kofi's best reading on a healthy day is 360 L/min.

2Asthma affects the airways, the branching tubes that carry air into the lungs. The wall of each airway has a lining tissue on the inside and a layer of muscle tissue around it. During an asthma flare, the lining swells and makes extra mucus, and the muscle tightens, so the airways become narrower. Tree and grass pollen are common triggers for many people with asthma.

3Four times during the year, Coach Brigid Farrell holds a pace check. Each runner jogs the same 1 km loop around the park pond at a steady pace of 6 minutes per kilometer. The coach rides a bike beside the group to keep the pace the same every time. Kofi always eats breakfast about two hours before a check, and before the loop he records his morning peak flow. Right after the loop, he counts his pulse for one minute. The coach also clips a pulse oximeter onto his fingertip. It shines light through the skin to estimate how much oxygen his blood is carrying, as a percent.

4The April check fell on a day with a high pollen count. During the loop, Kofi's chest felt tight and his legs felt heavy, even though the pace was the same as always. Afterward he followed his doctor's asthma plan and used his reliever inhaler, a medicine he breathes in that relaxes the muscle around the airways. Twenty minutes later, his peak flow was 330 L/min.