Why Does Saliva Get Thick When Running

When I go for a run, I often notice that my saliva gets thick and sticky, making it uncomfortable to swallow. It turns out, there are scientific reasons behind this common experience among runners. As I delved into understanding this phenomenon, I learned about the factors that contribute to the thickening of saliva during physical activity.


One of the primary reasons for thick saliva during running is dehydration. As I push my body during a run, I sweat profusely, causing a significant loss of fluids. This loss of fluids can lead to a decrease in saliva production, resulting in a thicker consistency. The body prioritizes retaining water for essential functions, which can affect the production of saliva, leading to the uncomfortable sensation of thick saliva in the mouth.

Breathing Through the Mouth

Another factor that contributes to the thickening of saliva is the act of breathing through the mouth while running. When I engage in intense physical activity, I often find myself breathing heavily through my mouth to meet the increased demand for oxygen. This mouth breathing can dry out the saliva, making it thicker and more viscous.

Reduced Salivary Flow

Physical exertion, such as running, can lead to a reduction in salivary flow. This reduction is a result of the body reallocating resources to support the muscles and organs involved in the physical activity. As a result, the saliva becomes thicker, making it more challenging to swallow and causing the sensation of dryness in the mouth.

Solutions and Precautions

Experiencing thick saliva during running can be uncomfortable, but there are measures that can be taken to mitigate this issue. Staying well-hydrated before, during, and after a run is crucial in maintaining normal saliva consistency. Sipping water or a sports drink can help combat dehydration and support saliva production. Additionally, using a mouth rinse or carrying a small amount of water to swish and spit during a run can also help alleviate the discomfort caused by thick saliva.


As a regular runner, I’ve come to understand the reasons behind the thickening of saliva during physical activity. Factors such as dehydration, mouth breathing, and reduced salivary flow all contribute to this common experience. By staying mindful of hydration and employing simple strategies to maintain saliva production, I’ve been able to minimize the discomfort and focus on enjoying my runs to the fullest.