Acute Effects of Aerobic Exercise on Affect and Smoking Craving in the Weeks Before and After a Cessation Attempt

Design and rationale for a randomized clinical trial testing the efficacy of a lifestyle physical activity intervention for people with HIV and engaged in unhealthy drinking

BACKGROUND

Among people living with HIV (PLWH), unhealthy drinking presents an increased risk for negative outcomes. Physical inactivity and sedentariness raise additional health risks. Despite evidence that physical activity (PA) is associated with improved physical and mental functioning and reduced alcohol cravings, there have been no PA studies conducted with PLWH engaged in unhealthy drinking. We describe a study protocol of a remote lifestyle physical activity (LPA) intervention to increase PA and reduce alcohol consumption among PLWH.

METHODS

Using online advertisements, 220 low-active PLWH engaged in unhealthy drinking will be recruited and randomized nationwide. After providing informed consent and completing a baseline interview, participants will receive a Fitbit. Participants will complete 15 days of ecologic momentary assessment through a phone application and up to 15 days of Fitbit wear time. Following this period, participants will be randomly assigned to a Fitbit-only control condition or a LPA and Fitbit intervention condition. Health counselors meet with control participants once (and have 6 subsequent brief check ins on Fibit use) and with intervention participants 7 times for PA counseling over a 12-week period. Follow-up assessments will be conducted at 3- and 6-months post-randomization. We hypothesize that individuals in the LPA and Fitbit condition will have lower rates of alcohol consumption and higher rates of PA at 6-month follow-up.

CONCLUSION

The randomized controlled trial described in this paper investigates remote methods to influence multimorbidity among PLWH using a LPA approach for increasing PA and reducing alcohol consumption.

Exercise and Smoking Cessation

Smoking is a public health crisis, leading to a multitude of health complications. Exercise is associated with numerous health benefits and is accepted by health professionals and smokers as a potentially effective smoking cessation aid. This chapter discusses the extant literature on the relation between exercise and smoking, including cross-sectional studies, experiments, and randomized clinical trials. There is robust evidence for exercise's efficacy in reducing cigarette craving, tobacco withdrawal symptoms, and negative affect. Further, exercise-based interventions appear to boost short-term abstinence yet may fall short of facilitating long-term abstinence. Methodological limitations of extant work are reviewed. We conclude with a discussion of the next steps in this line of work to fine-tune exercise interventions and their application for smoking cessation.

Affective Responses to Acute Exercise: A Meta-Analysis of the Potential Beneficial Effects of a Single Bout of Exercise on General Mood, Anxiety, and Depressive Symptoms

OBJECTIVE

Acute exercise elicits various biobehavioral and psychological responses, but results are mixed with regard to the magnitude of exercise-induced affective reactions. This meta-analysis examines the magnitude of general mood state, anxiety, and depressive symptom responses to acute exercise while exploring exercise protocol characteristics and background health behaviors that may play a role in the affective response.

METHODS

A total of 2770 articles were identified from a MEDLINE/PubMed search and an additional 133 articles from reviews of reference sections. Studies had to have measured general mood before the acute exercise bout and within 30 minutes after exercise completion. Effect sizes were estimated using Hedges' g , with larger values indicating improvement in the outcome measure.

RESULTS

A total of 103 studies were included presenting data from 4671 participants. General mood state improved from preexercise to postexercise ( g = 0.336, 95% confidence interval [CI] = 0.234-0.439). Anxiety ( g = 0.497, 95% CI = 0.263-0.730) and depressive symptoms ( g = 0.407, 95% CI = 0.249-0.564) also improved with exercise. There was substantial and statistically significant heterogeneity in each of these meta-analyses. This heterogeneity was not explained by differences in participants' health status. Meta-regression analyses with potential moderators (intensity of exercise, mode of exercise, usual physical activity level, or weight status of participants) also did not reduce the heterogeneity.

CONCLUSION

This meta-analysis shows significantly improved general mood, decreased anxiety, and lower depressive symptoms in response to an acute bout of exercise. There was substantial heterogeneity in the magnitude of the effect sizes, indicating that additional research is needed to identify determinants of a positive affective response to acute exercise.

Acute effects of outdoor and indoor walking on cigarette cravings, withdrawal symptoms and affective response during temporary smoking abstinence

RATIONALE

Cigarette smoking is one of the leading preventable causes of premature death worldwide. There is evidence in the literature that brief exercise units indoors can improve well-being in temporarily abstinent smokers and reduce cigarette cravings and withdrawal symptoms.

OBJECTIVE

Because exercise in natural environments showed enhanced psychological effects, the aim of our study was to examine the acute effects of outdoor exercise compared with indoor exercise on craving, withdrawal symptoms and affective response in temporarily abstinent smokers.

METHODS

In a randomized controlled within-subject-design, temporarily abstinent smokers (N = 16) participated in three interventions lasting 10 min: outdoor walking (OUT-EX), indoor walking (IN-EX) and a sedentary control condition (CC). Self-reported cigarette craving, withdrawal symptoms and affective response were assessed pre-, mid-, post-interventions and at follow-up.

RESULTS

In contrast to CC, OUT-EX and IN-EX significantly reduced cigarette cravings during and at the end of the intervention compared to pre-intervention, but not at 20 min follow-up. Cigarette withdrawal symptoms decreased significantly over time in all three groups, but no significant group differences were found. OUT-EX and IN-EX, but not CC, showed significantly improved affective valence at the end of the intervention and at follow-ups. Outdoor walking resulted in significantly lower cigarette cravings than indoor walking at the end of the intervention.

CONCLUSION

The study adds to existing evidence that short bouts of indoor or outdoor exercise can help reduce cigarette cravings and increase well-being in abstinent smokers. Further studies are needed to address the potential additional effect of outdoor exercise on craving, affective states and smoking cessation.

Effect of exercise intervention on smoking cessation: a meta-analysis

Background: Exercise has emerged as an effective approach to promote individual health and has shown potential in aiding smoking cessation. However, the specific benefits of exercise in smoking cessation remain unclear, and conflicting findings across studies may be attributed to variations in study populations and intervention characteristics. This study aims to conduct a meta-analysis to evaluate the impact of exercise interventions on tobacco dependence in smokers and assess the effectiveness of exercise in facilitating smoking cessation. Methods: A comprehensive search was performed in databases including PubMed, Web of Science, Embase, The Cochrane Library, and Scopus to identify relevant randomized controlled trials published before 30 October 2022. The Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines were followed during the review process. The quality of evidence (QoE) was assessed with GRADE (grading of recommendations, assessment, development and evaluations) methodology. Results: Acute exercise was found to significantly reduce smoking cravings [MD = -1.84, 95% CI (-2.92, -0.76), p < 0.001; SMD = -1.64, 95% CI (-2.22, -1.05), p < 0.001] and alleviate most withdrawal symptoms in smokers. However, there was no significant difference in the smoking cessation rate between the exercise group and the control group (p > 0.05). Exercise was associated with increased positive mood [SMD = 0.36, 95% CI (0.14, 0.58), p = 0.001] and reduced negative mood in smokers [SMD = -0.26, 95% CI (-0.39, -0.12), p < 0.001]. Conclusion: Acute exercise interventions effectively reduce cravings and withdrawal symptoms in smokers. However, long-term exercise interventions do not significantly improve the smoking cessation rate. Exercise can help reduce negative mood and enhance positive mood in smokers. Smokers with high levels of tobacco dependence may derive less benefit from exercise. Factors such as literature quality, exercise intervention characteristics, and exercise adherence may influence the effectiveness of interventions. Trial registration: This research protocol was registered in the International Prospective Register for Systematic Reviews (PROSPERO https://www.crd.york.ac.uk/PROSPERO/). Registration number: CRD42022326109.

A possible anti-anxiety effect of appetitive aggression and a possible link to the work of Donald Winnicott

Various pleasant sensations that give a particularly intense pleasure are able to improve anxiety. In the present study I consider the possibility that their anti-anxiety action depends on the strong pleasure they provide, and I propose a possible mechanism of this action. According to some studies, also appetitive aggression (an aggression that provokes a strong pleasure and that is performed only for the pleasure it provides) can improve anxiety, and in this article I consider the possibility that the pleasure of appetitive aggression is able to reduce anxiety by the same mechanism I have proposed for other intense pleasurable sensations.

The aggression performed by a child against the mother or against a substitute for the mother in the first period of life (a period in which this aggression is not dangerous) is a recurring theme throughout the work of of Donald Winnicott. Winnicott stresses that this aggression is necessary for the normal development of the child, and that the child must be free to practise it. According to Winnicott, this aggression is highly pleasurable and is not a response to unpleasant or hostile external situations. For these characteristics it seems to correspond to appetitive aggression in the adult that has been found to be able to reduce anxiety. Consequently, aggression performed by the child in the first period of life may also relieve anxiety, in the same way that appetitive aggression helps against anxiety in the adult.

In his writings, Winnicott returns several times to an unthinkable or archaic anxiety that children experience when they feel abandoned by their mother for a period that is too long for them, and all children, according to Winnicott, live on the brink of this anxiety. In this study I propose the hypothesis that aggression in the early period of life may be necessary for children because the intense pleasure it provides may help them against this continuously impending anxiety.

Effects of acute aerobic exercise on food-reward mechanisms in smoking-addicted individuals: An fNIRS study

PURPOSE

In addition to its toxic effects on the human cardiovascular and respiratory systems, tobacco dependence also causes damage to brain function and cognitive activity. Therefore, the main objective of this study was to investigate the effects of acute aerobic exercise on food-reward function and its food-cued prefrontal brain activation in tobacco-dependent individuals.

METHOD

Ninety-three participants who met the study criteria were randomly divided into a moderate-intensity exercise group (65%-75% HRmax), a high-intensity exercise group (75%-85% HRmax), and a quiet control group (n = 31 in each group). Participants were asked to perform a 35-minute target-intensity exercise or rest. The participants took the Leeds Food Preference Questionnaire and the Visual Food Cues Paradigm Task immediately before the experiment and immediately after completing the exercise or control intervention, and oxyhemoglobin concentrations in each prefrontal brain region were measured at the same time as the Visual Food Cues Paradigm Task.

RESULTS

Acute aerobic exercise significantly increased implicit cravings for low-calorie sweets in nicotine-dependent individuals (high: p = 0.040; moderate: p = 0.001), while acute moderate-intensity aerobic exercise also significantly increased the activation levels of the left dorsolateral prefrontal cortex (DLPFC: CH15: p = 0.030; CH22: p = 0.003) as well as the left orbitofrontal area (OFC: CH21: p = 0.007) in the food-reward brain region in nicotine-dependent individuals.

CONCLUSION

Acute aerobic exercise improves food-reward function and effectively increases activation levels in the DLPFC and OFC cerebral cortex in tobacco-dependent individuals, facilitating restoration of sensitivity to their drug-hijacked natural reward circuits.

Exercise in the Treatment of Addiction: A Systematic Literature Review

BACKGROUND

Exercise has been recognized as a promising and emerging treatment for individuals recovering from addiction. The purpose of this article was to systematically review scientific studies using exercise as a means to improve, sustain, or treat addictions, and to provide suggestions for the future use of exercise as a treatment method for addiction.

METHODS

Using PRISMA guidelines, a database search was conducted for articles that tested the impact of exercise interventions on addiction-related outcomes. To be included, peer-reviewed experimental design studies had to use human subjects to investigate the relationship between exercise and the treatment of or recovery from addiction. Garrard's Matrix Method was used to extract data from reviewed articles (n = 53).

RESULTS

Nearly three quarters of the studies reviewed documented a significant change in addiction-related outcomes (e.g., more days abstinent, reduced cravings) in response to exercise exposure, particularly while someone was receiving treatment at an in or outpatient clinic. Many studies investigated the effect of acute bouts of exercise on nicotine dependence, and many studies had small sample sizes, leaving room for future research on how exercise might benefit people recovering from substance and process addictions.

CONCLUSION

Results affirm that exercise can be a helpful aspect of addiction treatment. Future researchers should investigate different exercise settings (e.g., group-based exercise vs individual) and explore exercise maintenance and the long-term outcomes following discharge from treatment facilities.

Examining the effect of exercise on the relationship between affect and cravings among smokers engaged in cessation treatment

Cigarette smoking is associated with multiple adverse health outcomes. When smokers attempt to quit smoking, one of the leading predictors of relapse are cravings. Recent research shows a relationship between positive and negative affect, exercise, and cravings, but the exact nature of this relationship has yet to be understood. This study explored the relationships between positive and negative affect and cravings in a sample of participants with elevated levels of depressive symptoms (N = 202; 68.8% female; mean age = 46.1 years) who were enrolled in a smoking cessation trial to test the efficacy of a 12-week exercise intervention relative to a health education control on smoking outcomes. Data on affect and craving were gathered before weekly study intervention sessions, and data on cravings were gathered again after each session. The results showed that negative affect had a significant and positive association with cravings before an exercise or health education session. After the session, positive and negative affect were not significant predictors of changes in cravings from pre-session. However, regardless of level of positive or negative affect participants in the exercise condition showed greater reductions in craving pre- to post-class than those in the control condition. These findings suggest that negative affect is associated with cravings, but cravings can be mitigated by exercise.

Aerobic exercise as a promising nonpharmacological therapy for the treatment of substance use disorders

Despite the prevalence and public health impact of substance use disorders (SUDs), effective long-term treatments remain elusive. Aerobic exercise is a promising, nonpharmacological treatment currently under investigation as a strategy for preventing drug relapse. Aerobic exercise could be incorporated into the comprehensive treatment regimens for people with substance abuse disorders. Preclinical studies of SUD with animal models have shown that aerobic exercise diminishes drug-seeking behavior, which leads to relapse, in both male and female rats. Nevertheless, little is known regarding the effects of substance abuse-induced cellular and physiological adaptations believed to be responsible for drug-seeking behavior. Accordingly, the overall goal of this review is to provide a summary and an assessment of findings to date, highlighting evidence of the molecular and neurological effects of exercise on adaptations associated with SUD.

Smoking cessation for improving mental health

BACKGROUND

There is a common perception that smoking generally helps people to manage stress, and may be a form of 'self-medication' in people with mental health conditions. However, there are biologically plausible reasons why smoking may worsen mental health through neuroadaptations arising from chronic smoking, leading to frequent nicotine withdrawal symptoms (e.g. anxiety, depression, irritability), in which case smoking cessation may help to improve rather than worsen mental health.

OBJECTIVES

To examine the association between tobacco smoking cessation and change in mental health.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group's Specialised Register, Cochrane Central Register of Controlled Trials, MEDLINE, Embase, PsycINFO, and the trial registries clinicaltrials.gov and the International Clinical Trials Registry Platform, from 14 April 2012 to 07 January 2020. These were updated searches of a previously-conducted non-Cochrane review where searches were conducted from database inception to 13 April 2012.  SELECTION CRITERIA: We included controlled before-after studies, including randomised controlled trials (RCTs) analysed by smoking status at follow-up, and longitudinal cohort studies. In order to be eligible for inclusion studies had to recruit adults who smoked tobacco, and assess whether they quit or continued smoking during the study. They also had to measure a mental health outcome at baseline and at least six weeks later.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods for screening and data extraction. Our primary outcomes were change in depression symptoms, anxiety symptoms or mixed anxiety and depression symptoms between baseline and follow-up. Secondary outcomes  included change in symptoms of stress, psychological quality of life, positive affect, and social impact or social quality of life, as well as new incidence of depression, anxiety, or mixed anxiety and depression disorders. We assessed the risk of bias for the primary outcomes using a modified ROBINS-I tool.  For change in mental health outcomes, we calculated the pooled standardised mean difference (SMD) and 95% confidence interval (95% CI) for the difference in change in mental health from baseline to follow-up between those who had quit smoking and those who had continued to smoke. For the incidence of psychological disorders, we calculated odds ratios (ORs) and 95% CIs. For all meta-analyses we used a generic inverse variance random-effects model and quantified statistical heterogeneity using I2. We conducted subgroup analyses to investigate any differences in associations between sub-populations, i.e. unselected people with mental illness, people with physical chronic diseases. We assessed the certainty of evidence for our primary outcomes (depression, anxiety, and mixed depression and anxiety) and our secondary social impact outcome using the eight GRADE considerations relevant to non-randomised studies (risk of bias, inconsistency, imprecision, indirectness, publication bias, magnitude of the effect, the influence of all plausible residual confounding, the presence of a dose-response gradient).

MAIN RESULTS

We included 102 studies representing over 169,500 participants. Sixty-two of these were identified in the updated search for this review and 40 were included in the original version of the review.  Sixty-three studies provided data on change in mental health, 10 were included in meta-analyses of incidence of mental health disorders, and 31 were synthesised narratively.  For all primary outcomes, smoking cessation was associated with an improvement in mental health symptoms compared with continuing to smoke: anxiety symptoms (SMD -0.28, 95% CI -0.43 to -0.13; 15 studies, 3141 participants; I2 = 69%; low-certainty evidence); depression symptoms: (SMD -0.30, 95% CI -0.39 to -0.21; 34 studies, 7156 participants; I2 = 69%' very low-certainty evidence);  mixed anxiety and depression symptoms (SMD -0.31, 95% CI -0.40 to -0.22; 8 studies, 2829 participants; I2 = 0%; moderate certainty evidence).  These findings were robust to preplanned sensitivity analyses, and subgroup analysis generally did not produce evidence of differences in the effect size among subpopulations or based on methodological characteristics. All studies were deemed to be at serious risk of bias due to possible time-varying confounding, and three studies measuring depression symptoms were judged to be at critical risk of bias overall. There was also some evidence of funnel plot asymmetry. For these reasons, we rated our certainty in the estimates for anxiety as low, for depression as very low, and for mixed anxiety and depression as moderate. For the secondary outcomes, smoking cessation was associated with an improvement in symptoms of stress (SMD -0.19, 95% CI -0.34 to -0.04; 4 studies, 1792 participants; I2 = 50%), positive affect (SMD 0.22, 95% CI 0.11 to 0.33; 13 studies, 4880 participants; I2 = 75%), and psychological quality of life (SMD 0.11, 95% CI 0.06 to 0.16; 19 studies, 18,034 participants; I2 = 42%). There was also evidence that smoking cessation was not associated with a reduction in social quality of life, with the confidence interval incorporating the possibility of a small improvement (SMD 0.03, 95% CI 0.00 to 0.06; 9 studies, 14,673 participants; I2 = 0%). The incidence of new mixed anxiety and depression was lower in people who stopped smoking compared with those who continued (OR 0.76, 95% CI 0.66 to 0.86; 3 studies, 8685 participants; I2 = 57%), as was the incidence of anxiety disorder (OR 0.61, 95% CI 0.34 to 1.12; 2 studies, 2293 participants; I2 = 46%). We deemed it inappropriate to present a pooled estimate for the incidence of new cases of clinical depression, as there was high statistical heterogeneity (I2 = 87%).

AUTHORS' CONCLUSIONS

Taken together, these data provide evidence that mental health does not worsen as a result of quitting smoking, and very low- to moderate-certainty evidence that smoking cessation is associated with small to moderate improvements in mental health.  These improvements are seen in both unselected samples and in subpopulations, including people diagnosed with mental health conditions. Additional studies that use more advanced methods to overcome time-varying confounding would strengthen the evidence in this area.

Acute Aerobic Exercise Ameliorates Cravings and Inhibitory Control in Heroin Addicts: Evidence From Event-Related Potentials and Frequency Bands

Objective

Aerobic exercise is considered a potential adjunctive treatment for heroin addicts, but little is known about its mechanisms. Less severe cravings and greater inhibitory control have been associated with reduced substance use. The aim of the current study was to determine the effects, as measured by behavioral and neuroelectric measurements, of acute aerobic exercise on heroin cravings and inhibitory control induced by heroin-related conditions among heroin addicts.

Design

The present study used a randomized controlled design.

Methods

Sixty male heroin addicts who met the DSM-V criteria were recruited from the Isolated Detoxification Center in China and randomly assigned to one of two groups; one group completed a 20-min bout of acute stationary cycle exercise with vigorous intensity (70-80% of maximum heart rate, exercise group), and the other group rested (control group). The self-reported heroin craving levels and inhibitory control outcomes (measured by a heroin-related Go/No-Go task) were assessed pre- and post-exercise.

Results

The heroin craving levels in the exercise group were significantly attenuated during, immediately following, and 40 min after vigorous exercise compared with before exercise; moreover, during exercise, a smaller craving was observed in the exercise group than in the control group. Acute exercise also facilitated inhibition performance in the No-Go task. After exercise, the participants' accuracy, the N2d amplitudes, and the theta two band spectral power during the No-Go conditions were higher in the exercise group than in the control group. Interestingly, significant correlations between the changes in these sensitive measurements and the changes in cravings were observed.

Conclusions

This is the first empirical study to demonstrate that aerobic exercise may be efficacious for reducing heroin cravings and promoting inhibitory control among heroin addicts.

Factors Predicting 6-Month Smoking Cessation in Korean Adults

The purpose of this study was to identify factors predicting 6-month smoking cessation in Korean adult smokers. This descriptive correlation study assessed levels of urine cotinine, serum cotinine, serum serotonin, and 5-hydroxyindoleacetic acid; tobacco withdrawal symptoms; and resilience among 164 Korean adult smokers. Serum cotinine levels were negatively related to resilience at six months (r = -.42, p = .019), but were positively related to the amount of smoking (r = .32, p = .008) and with the Week 6 tobacco withdrawal symptoms score (r = .48, p = .001, n = 41). Higher resilience was associated with a higher 5-HIAA concentration. Greater therapy attendance, resilience, and withdrawal symptoms explained 35.3% of the variance in 6-month smoking cessation (Nagelkerke R² = .35, p < .001, n = 76). Efforts to increase counseling attendance rates and resilience and decrease withdrawal symptoms could be useful ways to improve smoking cessation rates.

Exercise interventions for smoking cessation

BACKGROUND

Taking regular exercise, whether cardiovascular-type exercise or resistance exercise, may help people to give up smoking, particularly by reducing cigarette withdrawal symptoms and cravings, and by helping to manage weight gain.

OBJECTIVES

To determine the effectiveness of exercise-based interventions alone, or combined with a smoking cessation programme, for achieving long-term smoking cessation, compared with a smoking cessation intervention alone or other non-exercise intervention.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group Specialised Register for studies, using the term 'exercise' or 'physical activity' in the title, abstract or keywords. The date of the most recent search was May 2019.

SELECTION CRITERIA

We included randomised controlled trials that compared an exercise programme alone, or an exercise programme as an adjunct to a cessation programme, with a cessation programme alone or another non-exercise control group. Trials were required to recruit smokers wishing to quit or recent quitters, to assess abstinence as an outcome and have follow-up of at least six months.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods. Smoking cessation was measured after at least six months, using the most rigorous definition available, on an intention-to-treat basis. We calculated risk ratios (RRs) and 95% confidence intervals (CIs) for smoking cessation for each study, where possible. We grouped eligible studies according to the type of comparison, as either smoking cessation or relapse prevention. We carried out meta-analyses where appropriate, using Mantel-Haenszel random-effects models.

MAIN RESULTS

We identified 24 eligible trials with a total of 7279 adult participants randomised. Two studies focused on relapse prevention among smokers who had recently stopped smoking, and the remaining 22 studies were concerned with smoking cessation for smokers who wished to quit. Eleven studies were with women only and one with men only. Most studies recruited fairly inactive people. Most of the trials employed supervised, group-based cardiovascular-type exercise supplemented by a home-based exercise programme and combined with a multi-session cognitive behavioural smoking cessation programme. The comparator in most cases was a multi-session cognitive behavioural smoking cessation programme alone. Overall, we judged two studies to be at low risk of bias, 11 at high risk of bias, and 11 at unclear risk of bias. Among the 21 studies analysed, we found low-certainty evidence, limited by potential publication bias and by imprecision, comparing the effect of exercise plus smoking cessation support with smoking cessation support alone on smoking cessation outcomes (RR 1.08, 95% CI 0.96 to 1.22; I² = 0%; 6607 participants). We excluded one study from this analysis as smoking abstinence rates for the study groups were not reported. There was no evidence of subgroup differences according to the type of exercise promoted; the subgroups considered were: cardiovascular-type exercise alone (17 studies), resistance training alone (one study), combined cardiovascular-type and resistance exercise (one study) and type of exercise not specified (two studies). The results were not significantly altered when we excluded trials with high risk of bias, or those with special populations, or those where smoking cessation intervention support was not matched between the intervention and control arms. Among the two relapse prevention studies, we found very low-certainty evidence, limited by risk of bias and imprecision, that adding exercise to relapse prevention did not improve long-term abstinence compared with relapse prevention alone (RR 0.98, 95% CI 0.65 to 1.47; I² = 0%; 453 participants).

AUTHORS' CONCLUSIONS

There is no evidence that adding exercise to smoking cessation support improves abstinence compared with support alone, but the evidence is insufficient to assess whether there is a modest benefit. Estimates of treatment effect were of low or very low certainty, because of concerns about bias in the trials, imprecision and publication bias. Consequently, future trials may change these conclusions.

Exercise during abstinence normalizes ultrastructural synaptic plasticity associated with nicotine-seeking following extended access self-administration

Nicotine-craving progressively increases, or incubates, over abstinence following extended access self-administration. While not yet examined for nicotine, the incubation of cocaine-seeking is accompanied by changes in synaptic plasticity in the nucleus accumbens. Here, we determined whether such changes also accompany enhanced nicotine-seeking following extended access self-administration and abstinence, and whether exercise, a potential intervention for nicotine addiction, may exert its efficacy by normalizing these changes. Given that in humans, tobacco/nicotine use begins during adolescence, we used an adolescent-onset model. Nicotine-seeking was assessed in male rats following extended access nicotine or saline self-administration (23-hr/day, 10 days) and 10 days of abstinence, conditions known to induce the incubation of nicotine-seeking, using a within-session extinction/cue-induced reinstatement procedure. A subset of rats had 2-hr/day access to a running wheel during abstinence. Ultrastructural alterations of synapses in the nucleus accumbens core and shell were examined using electron microscopy. Nicotine-seeking was elevated following extended access self-administration and abstinence (in sedentary group), and levels of seeking were associated with an increase in the density of asymmetric (excitatory) and symmetric (inhibitory) synapses onto dendrites in the core, as well as longer asymmetric synapses onto spines, a marker of synaptic potentiation, in both the core and shell. Exercise normalized each of these changes; however, in the shell, exercise and nicotine similarly increased the synapse length. Together, these findings indicate an association between nicotine-seeking and synaptic plasticity in the nucleus accumbens, particularly the core, and indicate that the efficacy of exercise to reduce nicotine-seeking may be mediated by reversing these adaptations.

Anxiety Sensitivity is Associated with Lower Enjoyment and an Anxiogenic Response to Physical Activity in Smokers

Background

The subjective affective response to, and enjoyment of, physical activity are strong predictors of engagement in physical activity. Anxiety sensitivity, the fear of bodily sensations, is a cognitive factor that may inhibit the pleasurable affective experience of physical activity, possibly contributing to low levels of physical activity. The current study evaluated anxiety sensitivity in relation to PA enjoyment and affective experience before and after exercise in smokers.

Method

Participants were low-active treatment-seeking smokers (n = 201) enrolled in a smoking cessation intervention. At baseline, participants completed self -report assessments of anxiety sensitivity, cigarette dependence, and physical activity enjoyment. State affect was also reported before and after a submaximal exercise test to index pre-exercise activity affect and affective response to exercise.

Results

Anxiety sensitivity was significantly negatively correlated with physical activity enjoyment, specifically lower enjoyable physical feelings of physical activity. Anxiety sensitivity was significantly correlated with lower state mood and higher state anxiety prior to the submaximal exercise test, and higher anxiety immediately after the exercise test. Additionally, anxiety sensitivity predicted increased anxiety, but not lower mood, in response to the submaximal exercise test.

Conclusions

This is the first study to document an association of anxiety sensitivity with affective determinants of physical activity behavior in smokers. Anxiety sensitivity was associated with lower physical activity enjoyment, higher negative affect prior to after exercise testing, and an anxiogenic response to exercise. Future work is needed to understand how the current findings generalize beyond smokers.

Neurobiology of substance use in adolescents and potential therapeutic effects of exercise for prevention and treatment of substance use disorders

Substance use (e.g., alcohol, marijuana, opioids, cocaine., etc,) use often initiates during adolescence, a critical period of physiological and social development marked by an increase in risk-taking due, in part, to heightened motivation to obtain arousal from rewards. Substance use during adolescence has been associated with a greater risk of substance use disorders (SUD) in adulthood. Although use rates for most substances have remained relatively stable, the frequency of marijuana use and the perception that regular marijuana use is not harmful has increased in adolescents. Furthermore, the nonmedical use of opioids has increased, particularly in the South, Midwest, and rural low-income communities. Substance use in adolescence has been associated with adverse structural and functional brain changes and, may exacerbate the natural "imbalance" between frontal/regulatory and cortical-subcortical circuits, leading to further heightened impulsive and reward-driven behaviors. Exercise increases growth and brain-derived neurotrophic factors that stimulate endogenous dopaminergic systems that, in turn, enhance general plasticity, learning, and memory. Exercise may help to reinforce the "naïve" or underdeveloped connections between neurological reward and regulatory processes in adolescence from the "bottom up" and "offset" reward seeking from substances, while concomitantly improving cardiovascular health, as well as academic and social achievement. In this review, we provide an overview of the current state of substance use in adolescents and rationale for the utilization of exercise, particularly "assisted" exercise, which we have shown increases neural activity in cortical-subcortical regions and may modulate brain dopamine levels during adolescence, a unique window of heightened reward sensitivity and neural plasticity, for the prevention and adjunctive treatment of SUD.

Exercise as a Sex-Specific Treatment for Substance Use Disorder

PURPOSE OF REVIEW

Exercise is a promising treatment for substance use disorder that may reduce withdrawal symptoms and prevent relapse. In this review, we discuss recent evidence from clinical and preclinical studies for its efficacy, from a behavioral to a molecular level, in order to understand the exercise conditions that lead to beneficial effects. We also highlight the few recent findings of sex-specific differences.

RECENT FINDINGS

Clinical and preclinical findings show that exercise decreases withdrawal symptoms, including craving, in both males and females. Evidence from clinical studies support the efficacy of exercise to prevent relapse to smoking, although further research is needed to examine sex differences, establish long-term efficacy, and to determine if effects extend to other substance use disorders. Preclinical findings also support the potential utility of exercise to prevent relapse with evidence suggesting that its efficacy is enhanced in males, and mediated by blocking drug-induced adaptations that occur during early abstinence.

SUMMARY

Sex differences and timing of exercise availability during abstinence should be considered in future studies examining exercise as an intervention for relapse. A better understanding of the neurobiological mechanisms underlying the efficacy of exercise to reduce withdrawal symptoms and prevent relapse is needed to guide its development as a sex-specific treatment.