Occasionally the human body produces a weird response to ordinary stimulation. For some people, training for a 5K might leave you feeling like you have itching powder in your running gear. If you're wondering: "Why am I so itchy during a workout," you're not alone. For many people, exercise literally makes their skin crawl. (And for others, it's just a figurative thing.)
In some cases, this itchiness can result from your skin coping with dry conditions. As explained on the website for Women's Running, if you deal with dry skin, then a workout may cause excessive skin irritation. Thankfully, much of this problem can be relieved with a pre-workout moisturizer application.
It's also possible that you're allergic to something in your workout clothes. Some people have allergies to the fabric that's often used to manufacture exercise clothes, as noted in the website for Women's Health. As further explained by the website, washing new clothes in a mild detergent may help, or you may need to use cotton fabrics for workouts instead.
Sometimes the itching is caused by your body's reaction to a new or more vigorous exercise. If it's been a hot minute since your last workout, then the expansion of your arteries and capillaries may be interpreted as an itch sensation in your brain, according to UPMC HealthBeat. Fortunately, though, this feeling will likely subside as your stamina increases. In this instance, the cause of itchiness is also the cure.
Lastly, you may want to consider your body's histamine response. According to WebMD, histamines are chemicals produced by your immune system to help your body get rid of allergens. This is normally a helpful reaction. Sometimes, however, your histamines get a little carried away and start attacking harmless things as though they're a threat, and this results in allergy symptoms, as further explained by WebMD.
When some people work out, an allergic reaction called urticaria occurs. Urticaria is triggered by the release of histamines, which enlarge blood vessels and often cause itchy, red welts to appear on the skin, as noted by Very Well. Working out in cooler temperatures, or adopting a less strenuous workout routine, may help in this case, as further explained by Very Well.
As always, if these or any other medical symptoms are concerning you, then a trip to the physician is always smart. There may be something specific to your situation that's causing this reaction. Otherwise, hopefully your future workouts will be itch-free and fantastic.