During exercise, different parts of your body work more than others — and stay warmer than others — based on how active they are, which explains why you may feel the sensation of a cold tummy when running. Here's why this might be happening on your run, and what other things can factor in, too.
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Read more: Getting Chills While Running
Exercise and Heat Transfer
Your muscles are hard at work during exercise, some more so than others, depending on the workout. Even though runners know a strong core is important for posture, your core isn't working as hard as some of your other large muscle groups, such as your quads. An August 2019 study, published in the International Journal of Environmental Research and Public Health, notes the transfer of heat from the core to the limbs during exercise. The highest skin temperatures are found in the more active muscles in your legs and arms.
Luke Belval, PhD, CSCS, a post-doctoral research fellow at the Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital of Dallas, notes that muscles generate heat during exercise. If your stomach feels cold after exercise, an explanation could be that the muscles are cooler as they are less active.
"Comparatively, your torso is not generating as much heat during exercise," Belval explains. "One of the functions of the increased blood flow is to carry heat away from the muscles to the skin where it can be released into the environment. Your legs could feel warmer because the muscles are likely warmer."
Your muscles demand increased blood flow during exercise so they get the oxygen they need. To meet these demands, an April 2015 study in Physiological Reviews explains that when you're exercising, blood is diverted from less active muscles and tissues toward the muscles being primarily used. Specific to the torso, Belval notes that blood is also diverted from the organs such as the kidneys, stomach and liver.
Training and Sweat Factors
How you experience temperature may be due to the way you exercise. Skin temperature and performance in runners can differ depending on where the running is occurring — such as treadmill versus indoor track — as shown in a February 2015 study in the Journal of Strength and Conditioning Research.
When paired with other factors, such as sweat and the amount of evaporation, a runner may also experience different temperature sensations. According to the U.S. National Library of Medicine, when your sweat evaporates, it cools your body, and Belval notes that there is a complex interaction between how we sense temperature and wetness.
"Your torso is a large surface area for this sweat to evaporate and cool," Belval says, and "...If that sweat was trapped under a shirt, you may be confusing the perception of wetness with cold, whereas the sweat has evaporated on the skin where clothing wasn't covering."
There does not appear to be any research that focuses specifically on the feeling of the stomach being cold during or after exercise, but there have been findings for this feeling in the feet and hands, and Belval acknowledges this is a normal occurrence.
A November 2017 study of 58 female athletes published in Physiological Reports found that women who were cold-sensitive had a cold sensation in the fingers and toes during and after exercise in temperatures of roughly 75 degrees Fahrenheit. In other words, there are groups of people who tend to be more sensitive to cold.
Unfortunately, science doesn't definitively pinpoint why you may experience a cold stomach during exercise. However, Belval hypothesizes that understanding how your body reacts to exercise, how sweat regulates your temperature and the simple fact that everyone experiences sensations of hot and cold differently leads to a possible explanation.
Heat is a stressor on the body, and according to the Mayo Clinic, your body's natural cooling system can have a tougher time regulating in certain weather conditions. Thus, paying closer attention to additional factors, such as the weather, your clothing, the amount you sweat and whether or not you are cold-sensitive, may help you pinpoint elements that are specific to your temperature sensation and experience.
Read more: Causes of Night Sweats After Exercising
Is This an Emergency?
- Luke Belval, PhD, ATC, CSCS, post-doctoral research fellow, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas
- International Journal of Environmental Research and Public Health: “The Dynamic and Correlation of Skin Temperature and Cardiorespiratory Fitness in Male Endurance Runners”
- Journal of Strength and Conditioning Research: “Running Performance, Pace Strategy, and Thermoregulation Differ Between a Treadmill and Indoor Track”
- Physiological Reports: “Body Temperature and Cold Sensation During and Following Exercise Under Temperate Room Conditions in Cold-Sensitive Young Trained Females”
- U.S. National Library of Medicine: “Sweating”
- Physiological Reviews: “Regulation of Increased Blood Flow (Hyperemia) to Muscles During Exercise: A Hierarchy of Competing Physiological Needs”
- Mayo Clinic: “Heat and Exercise: Keeping Cool in Hot Weather”