Right now, summer weather is real in the Mid-Atlantic. This record heat and high humidity will impact your run by demanding more of your energy and resources - planning ahead for these conditions is a must.
Although humid air feels heavy, it is actually lighter and less dense than non-humid air. Nonetheless, research has shown that high humidity is proven to exacerbate asthma symptoms; though using an inhaler prior to athletic activity on a humid day is proven to prevent attacks, researchers don’t have a clear idea of why. In my experience, humidity can make normal breathing feel like a challenge by causing heaviness in the chest, even shortness of breath.
In any case, while heat and humidity do not make for my favorite running conditions, I’ve learned that with adequate preparation, they don’t need to be a deal breaker. Here are a few strategies I use when running on a humid day (of note: the terms “long run” and “short run” are relative to your experience. For me, long run = 10+ miles; short run = sub-9 miles):
After your hot, humid run, take time to cool off, replenish your nutrients, and get some rest. You've earned it!