Skin temperature measurements by infrared thermography during running exercise

• Skin temperature response to exercise for a group of runners has been measured by infrared thermography.
• Measurements were performed during overground and treadmill running exercise.
• Running exercise was found to exert a marked effect on the skin temperature.
• Fall in skin temperature during initial running activity has been found.
• Skin temperature decrease is associated with cutaneous vasoconstriction response to exercise.

The thermal interaction of human body and the environment during running activity is an important mechanism that may affect the athletic performance. Skin temperature plays the fundamental role of regulating the heat exchange by convection, radiation and evaporation. In this study, the skin temperature response to running exercise has been tested by infrared thermographic imaging, a highly reliable method for the real time, non-invasive monitoring of local cutaneous temperature over the body surface. Measurements performed for long-distance runners showed a fall in skin temperature during the initial stage of running exercise, regardless of the type of work (overground or treadmill) and environmental (outdoor or indoor) conditions. It is argued that this skin temperature decrease is associated with the cutaneous vasoconstrictor response to exercise. A continuous increase in load intensity (as occurs during an incremental treadmill exercise) may produce further reductions in skin temperature; conversely, a constant load running exercise is likely to promote the attainment of a relative minimum of skin temperature, followed by a gradual little rise over time related to thermoregulatory vasodilation.