BackgroundDespite a steady world-wide decline over recent decades, rates of smoking remain high in developed countries. In Japan, 30% of men and 10% of women are smokers. Based on these rates, 18.8 million (14.06 million men and 4.74 million women) in Japan are smokers. The rate of success for smoking cessation has recently improved due to the widespread availability of drug therapy; however, the success rate for quitting smoking one year after beginning therapy is only around 50%. Previous studies have demonstrated that exercise can relieve mental stress during continuous abstinence from smoking and curb smoking resumption. To date, no large-scale, randomized controlled trials have examined the effects of exercise on smoking cessation. The present study aims to determine the effects of exercise instruction on continuous abstinence from smoking after completion of smoking cessation therapy.MethodsThis is a multicenter, prospective, parallel-group, randomized controlled trial in Japan. We will enroll 300 individuals visiting a smoking cessation clinic (over 3 months) who have abstained from smoking in the second month after their initial visit as potential participants. Participants will not habitually exercise and will need to consent to participate. Participants will be randomly assigned to the exercise intervention group or control group. The intervention group will receive instruction on exercises that can be incorporated into their daily lives. The control group will be followed during the standard smoking cessation support program. The primary endpoint will be the continuous abstinence rate, and secondary endpoints will be weight, blood pressure, exhaled carbon monoxide concentration, psychological state, and blood test results. These indices will be compared between the intervention and control groups, with follow-up periods of 9 months in both groups.DiscussionBy examining the effects of exercise instruction after completion of 12-week smoking cessation therapy, this study should yield quality information that can be used to develop protocols to improve the continuous abstinence rate and inhibit weight gain after smoking cessation therapy.Trial registrationUMIN Clinical Trials Registry, UMIN000014615. Registered on 1 October 2014.