Penny Weston , a fitness and nutrition expert, was first diagnosed with asthma when she started PE classes in school. She noticed running up the stairs would get her out of breath. I avoided any sport or PE and just wasnt active, she said.

Weston knows how debilitating and upsetting it can be when exercise is extra difficult because of asthma, especially if youre someone who enjoys moving your body. But what happens inside your body when you have an asthma episode, and how can you still enjoy exercise when that can happen?

What asthma looks like in the context of exercise

A good way to picture this is to imagine trying to walk whilst breathing through a straw, explained Dr. Paul OConnell, a general practitioner from Cardiff, Wales, who recently launched Physical Nutrition . When we exercise, our bodies require more air and oxygen, and this requires the lungs to work harder. If your airways are inflamed and narrow, then getting air into them (and carbon dioxide out of them) is harder.

Asthma is about how lungs interact with the environment, too. People with asthma have breathing tubes airways or bronchi that are extra sensitive to triggers in the environment, explained Dr. Sophie Vergnaud , a pulmonologist, hospitalist and medical editor for GoodRx. When the airways are triggered, they become swollen and tight, making it hard for air to move through them. This can lead to bronchoconstriction, which causes wheezing, shortness of breath, chest tightness and coughing.

Its important to note that theres a difference between asthma and exercise-induced asthma (also clinically known as EIB). Vergnaud explained EIB is similar to asthma, but it only happens in response to exercise.

It matters because sometimes, people who get symptoms while exercising get diagnosed with EIB, but they actually have asthma, Vergnaud said. The bottom line is if someone has EIB, they need to be formally tested for asthma.

Is it asthma or the usual out-of-breath feeling that comes with a workout?

But wait, isnt a little bit of breathlessness normal when youre exerting yourself? It depends.

You will probably need to stop, and you may find that it takes you longer than usual to recover, Vergnaud said. If your symptoms improve with your quick-relief inhaler, like albuterol, then thats a good sign you were experiencing bronchoconstriction.

Another sign, she said, is noticing symptoms starting when youre exposed to a triggering environment (like cold, dry air) or those symptoms not improving as you continue to work out regularly (and rest!).