We all know that smoking is bad for us, but quitting can be hard. Withdrawal symptoms such as irritability, trouble sleeping, or even depression are commonly reported by people struggling with tobacco addiction.
In addition to specialized support services that might help you to deal with these symptoms, meditation and avoiding smoking triggers are also helpful methods.
Exercise is known to reduce nicotine withdrawal symptoms. Older studies have shown that even a short 10-minute bout of moderate exercise can have immediate effects of reducing tobacco cravings.
The exact mechanisms responsible for this effect remain largely unknown. But new research brings us closer to understanding these mechanisms, as it shows how various degrees of exercise intensity affect nicotine cravings in mice.
Dr. Alexis Bailey, senior lecturer in neuropharmacology at St George's University of London in the United Kingdom, is the corresponding author of the study, and the findings were published in the British Journal of Pharmacology.
How exercise helps nicotine-dependent mice
Dr. Bailey and his team treated mice with nicotine for 14 days and then subjected them to one of three wheel running regimens: 24 hours per day, 2 hours per day, or no exercise at all.
On the 14th day, the researchers assessed the rodents' withdrawal symptoms. Brain sections of the mice were also analyzed.
It was found that "nicotine-treated mice undertaking 2 or 24 hrs day wheel running displayed a significant reduction of withdrawal symptom severity compared with the sedentary group."
Additionally, in the mice that exercised, the researchers were able to see an increase in the activity of a type of nicotine brain receptor called alpha7 nicotinic acetylcholine. The receptor was located in the mice's hippocampus, a brain area associated with creating new memories and implicated in mood disorders.
Interestingly, 2 hours of exercise every day seemed to be just as good for relieving withdrawal symptoms as exercising continuously for 24 hours. This suggests that the beneficial effects of exercise do not depend on the intensity of the exercise.
"These findings support the protective effect of exercise preceding smoking cessation against the development of physical dependence, which may aid smoking cessation by reducing withdrawal symptom severity," write the authors.
As the team explains, "[O]ur results demonstrate the effectiveness of even a moderate amount of exercise during nicotine exposure in attenuating nicotine withdrawal symptoms and point toward the hippocampal [alpha7 nicotinic acetylcholine] system as a potential mechanism underlying this effect."
"These findings may also have implications for the development of targeted interventions prior to smoking cessation which may increase the chances of smoking cessation," add Dr. Bailey and colleagues.
To the authors' knowledge, this is the first time that such a profound effect of exercise on animals addicted to nicotine has been shown in a study.
"The evidence suggests that exercise decreases nicotine withdrawal symptoms in humans [...] Our research has shed light on how the protective effect of exercise against nicotine dependence actually works."
Dr. Alexis Bailey
However, the study authors also caution that the evidence is not yet sufficient to establish causality between the increased activity of the hippocampal nicotine receptor and the beneficial effects of exercise.