TY  - JOUR
PY  - 2016//
TI  - The effects of smoking and nicotine ingestion on exercise heat tolerance
JO  - Journal of basic and clinical physiology and pharmacology
A1  - Druayn, Amit
A1  - Atias, Danit
A1  - Ketko, Itay
A1  - Cohen-Sivan, Yoav
A1  - Heled, Yuval
SP  - 167
EP  - 170
VL  - 28
IS  - 2
N2  - BACKGROUND: Smoking has a thermogenic effect and is associated with low physical performance. Nevertheless, a direct, quantitative effect of acute smoking on exercise heat tolerance has not been reported. <br><br>METHODS: Sixteen healthy young male volunteers, eight cigarette smokers, and eight non-smokers participated in the study. All subjects performed a maximal oxygen consumption test (VO2max) and a standardized heat tolerance test (HTT) after at least 12 h without smoking under the following conditions: no nicotine exposure, 10 min after nicotine exposure (2 mg nicotine lozenge), and 10 min after smoking two cigarettes (0.8 mg nicotine in each cigarette, smokers only). <br><br>RESULTS: There was no significant effect of nicotine exposure on physiological performance and heat tolerance in the non-smokers group. In the smokers group, cigarette smoking, but not nicotine ingestion, resulted with higher heart rate (by 9±9 bpm) at the end of the HTT (p<0.05). Moreover, both smoking and nicotine ingestion increased smokers' rectal temperature at the end of the HTT (by 0.24±0.16°C and 0.21±0.26°C, respectively, p<0.05) and were associated with higher sweat rate during the HTT (by 0.08±0.07 g/h and 0.06±0.08 g/h, respectively, p<0.05). Heart rate variability (HRV) analysis also revealed a higher LF/HF (low frequency/high frequency) ratio after exposure to nicotine and smoking in the smokers group compared with no exposure (2.13±2.57 and 2.48±2.76, respectively, p<0.05), indicating a higher sympathetic tone. <br><br>CONCLUSIONS: According to this preliminary study, cigarette smoking and nicotine ingestion increase the physiological strain during a HTT in smokers. Acute smoking may, therefore, increase heat intolerance and the risk to heat injuries.<p />  <p>Language: en</p>
LA  - en
SN  - 0792-6855
UR  - http://dx.doi.org/10.1515/jbcpp-2016-0065
ID  - ref1
ER  -