Influence of Ambient Temperature on Autonomic Nerve Function and Peripheral Sensation from Moderate-Intensity...

The main objective was to ascertain the acute responses in autonomic nervous activity and peripheral sensation induced by moderate-intensity treadmill exercise performed under different ambient temperatures.

Twelve young healthy subjects underwent three sessions of moderate-intensity treadmill exercise (warming, 5 min and running, 25 min), on different days under 10°C, 20°C and 30°C room temperatures. Pre- and post-intervention, heart rate variability (HRV) and plantar vibrotactile perception threshold (VPT) were measured. Additionally, rate of perceived exertion (RPE) was recorded after intervention.

In comparison with the corresponding baseline values, after intervention, low frequency power (LF) and LF/high frequency power (HF) of HRV increased significantly and HF decreased significantly under the condition of 10°C only (p < .005). Following intervention, VPT increased significantly at the hallux for 31.5 Hz test frequency under 30°C and at the heel for 31.5 Hz test frequency under 10°C (both p < .05). In contrast, VPT decreased significantly at the hallux for 125 Hz test frequency under 10°C (p < .005). Exposure under the temperature of 20°C did not result in any significant change in VPT. After intervention, RPE under 30°C showed significantly higher values than those under 20°C (p < .01) and 10°C (p < .005) conditions with no difference between the latter two conditions.

Treadmill exercise under 20°C ambient temperature did not exert any negative impacts on autonomic and peripheral nerve function and resulted in a perceived exertion of moderate intensity among the study participants. Therefore, an ambient temperature around 20°C might be recommended for the mentioned purpose.