Dynamic thermography: Analysis of hand temperature during exercise

Exercise has a noted effect on skin blood flow and temperature. We aimed to characterize the normal skin temperature response to exercise by thermographic imaging. A study was conducted on ten healthy and active subjects (age=25.8±0.7 years) who were exposed to graded exercise for determination of maximal oxygen consumption (V̇O₂ max), and subsequently to constant loads corresponding to 50%, 70%, and 90% of V̇O₂ max. The skin temperature response during 20 min of constant load exercise is characterized by an initial descending limb, an ascending limb and a quasi-steady-state period. For 50% V̇O₂ max, the temperature decrease rate was -0.0075±0.001 °C/s during a time interval of 390±47 s and the temperature increase rate was 0.0055± 0.0031 °C/s during a time interval of 484±99 s. The level of load did not influence the temperature decrease and increase rates. In contrast, during graded load exercise, a continuous temperature decrease of -0.0049±0.0032 °C/s was observed throughout the test In summary, the thermographic skin response to exercise is characterized by a specific pattern which reflects the dynamic balance between hemodynamic and thermoregulatory processes.