High-Intensity interval training and continuous aerobic exercise interventions to promote self-initiated quit attempts in young adults who smoke: Feasibility, acceptability, and lessons learned from a randomized pilot trial

Objectives: While exercise significantly reduces craving for cigarettes, the effect of exercise on self-initiation of quit attempts is less known. Therefore, this randomized pilot study explored the effect of starting an exercise program on self-initiated quit attempts, and also the feasibility and acceptability of a novel exercise intervention, high-intensity interval training (HIIT), as compared with a more traditional continuous aerobic (CA) exercise intervention. Methods: Participants smoked (5 cigarettes/d), were aged 18 to 40 years, and wanted to increase their exercise. Participants were randomized into 1 of 3 groups: HIIT, CA, and delayed control. All participants attended follow-up visits at weeks 4, 8, and 12. Outcomes included measures of feasibility (eg, visit attendance) and acceptability (eg, satisfaction), and also changes in smoking behavior (eg, quit attempts during follow-up) and proxies to quit attempts (eg, positive affect). Results: Overall, there were no differences in terms of feasibility and acceptability between the HITT (n=12) and CA (n=9) groups. Based on both self-report and objective measurement, the exercise groups (HIIT and CA) increased their physical activity as compared with the delayed treatment group (n=11). Compared with HIIT and delayed control, CA (n=9) had significant favorable changes in positive affect (eg, at week 8, HIIT: +0.25±2.21, delayed control: 5.11±2.23, CA: +5.50±2.23; P=0.0153). Conclusions: These observations suggest that HIIT is as feasible and acceptable as CA, though CA may have a more favorable effect on proxies to quit attempts (eg, positive affect). Fully powered studies are needed to examine the effect of HIIT versus CA on quit attempts.