Title

Effects of resistance exercise on the HPA axis and cardiovascular responses to psychological stress during short-term smoking abstinence in men

Date of Completion

January 2009

Keywords

Health Sciences, Recreation

Degree

Ph.D.

Abstract

Recent evidence has shown that early smoking relapse is associated with dysregulated stress response and exaggerated mood state. Although exercise has been shown to be another effective intervention to smoking cessation, no study has yet investigated the role of exercise in mediating the stress systems during short-term smoking abstinence. Purpose. The purposes of this study were to examine the effects of resistance exercise on (1) the HPA axis and cardiovascular responses to mental challenge; (2) withdrawal symptoms, urge to smoke and stress, during 24-hour smoking abstinence in men. Methods. 8 sedentary male smokers (mean ± SD age: 20.1 ± 1.7 y; height: 171.6 ± 10.8 cm; body mass: 70.4 ± 12.0 kg; smoking history: 2.9 ± 0.8 y) completed 24-hour ad libitum smoking trial followed by two 24-hour smoking abstinence trials in which subjects perform 6 whole body resistance exercises (EX) or rest (NEX) in the morning followed by mental challenge in the afternoon. Salivary and serum cortisol, adrenocorticotropin hormone (ACTH), heart rate (HR), systolic and diastolic blood pressure (SBP, DBP) were measured at pre-abstinence (Rest), before and after exercise or rest time (Pre-AM, IP-AM and 30-AM), before and after mental challenge (Pre-PM, IP-PM and 30-PM). Results. Resistance exercise significantly (p≤0.05) elevated plasma ACTH, serum cortisol, HR and SBP at IP-AM during EX trial compared to ad libitum smoking or NEX trials. However, the resting ACTH, salivary and serum cortisol concentrations at Pre-PM were not significantly different between EX and NEX trials. In contrast, HR (p=.051) and SBP were significantly higher at Pre-PM during EX trial. The HPA axis response to mental challenge was not significantly different between EX and NEX trials, though HR response to mental challenge was significantly greater during EX trial. A bout of resistance exercise did not reduce the withdrawal symptoms, urge to smoke and stress. Conclusion. These findings indicate that the resting HPA axis hormones after 24 hours of abstinence were not affected by resistance exercise performed earlier. Neither was the HPA axis response to the subsequent mental challenge affected by resistance exercise. However, HR response to mental challenge was enhanced by resistance exercise performed earlier. ^