Walking as few as 20 minutes a day is enough to help teenage smokers decrease the amount they smoked; increasing the time by 10 minutes increased the likelihood they’d kick the habit altogether, according to research published online ahead of print in the Journal of Adolescent Health, the official publication of the Society for Adolescent Medicine.

“Teens who boosted the number of days on which they engaged in at least 20 minutes of exercise, equivalent to a short walk, were more likely than their peers to resist lighting up a cigarette,” said lead author Kimberly Horn, EdD, the Associate Dean for Research at the George Washington University School of Public Health and Health Services (SPHHS).

Investigators put some teen participants through an intensive anti-smoking program combined with a fitness intervention, while others just got the smoking cessation program; a third group only listened to a short anti-smoking lecture. All teens increased their exercise activity to some degree, but those who reported increasing the number of days they exercised for 20 minutes were able to significantly cut back on the number of cigarettes smoked.

“We don’t fully understand the clinical relevance of ramping up daily activity to 20 or 30 minutes a day with these teens. But we do know that even modest improvements in exercise may have health benefits,” said Horn. “Our study supports the idea that encouraging one healthy behavior can serve to promote another, and it shows that teens, often viewed as resistant to behavior change, can tackle two health behaviors at once.”