Table 3.

Studies investigating EX in the therapy of illicit drug abuse/dependence.

First author, year	Sample characteristics	Study design, standard therapy	Exercise intervention (EX)	Control condition(s)	Outcome variables and findings Exercise > control condition	Comments
Collingwood et al. (1991) [37]	- N = 74 teenagers (mean 16.8 y) - at-risk of drug abuse or abusing drugs or drug-dependent (m, f) - Ethnicity not reported	- N = 54 secondary school at-risk classes drug prevention program - N = 11 community-based substance abuse counseling agency program duration - N = 6 weeks N = 9 inpatient chemical dependency unit treatment - Duration: 8 weeks	- Duration: 9 Weeks - 1-2 times/week supervised group EX, 2 individual weekly training sessions - 60–90 min, stretching, strength development, individual aerobic EX	- None - statistical comparison between subjects with (N = 38) versus without (N = 36) significantly increased fitness (“improvers” versus “non-improvers”)	- “Improvers”: significantly fewer multiple drug users and alcohol uses per week, and higher abstinence rate (but no differences concerning the use of individual substances) - Significantly higher flexibility and strength, and lower body fat Stronger decrease of depression and anxiety, more positive self-concept	- No experimental design - Post hoc classification possibly confounded with other variables (EX adherence and abstinence may depend on the same external factors; causality is not given) - Heterogeneity of diagnoses and institutions - Significant differences between groups concerning initial fitness levels, self-concept, abstinence rates, depression, and anxiety - Drug use only assessed by self-report
Burling et al. (1992) [38]	- N = 218 veterans with drug and/or alcohol abuse or dependence (m) - Mixed sample (50% Black, 41% White, 9% other)	- Inpatient rehabilitation program for homeless substance-dependent veterans - Group-based CBT skills training - Duration ≥ 30 days	- Duration ≥ 30 days (optional continuation as outpatient) - Softball team (N = 34): 2 trainings, one game (men's city league), one team meeting/week	- Two control cohorts: - A:  N = 102, patients treated at the same time who chose not to participate in EX - B: N = 82, patients treated 1 year prior to EX cohort	- Significantly higher abstinence rate in softball cohort at 3-month followup - Trend for higher employment and dwelling - Significantly higher treatment duration and completion	- Unequal group sizes (32 : 102 : 82) - Self-selection of participants, no randomization - Lack of pure EX intervention includes social interaction, team-building, and time structuring - Lack of equal contact time control group controlling for these factors - Cultural specificity of softball (lack of generalizability)
Palmer et al. (1995) [39]	- N = 45 patients with “problems with alcohol, cocaine or other drugs” (m, f) - (diagnoses not specified) - Mixed sample (60% Black, 40% White)	- Inpatient rehabilitation program - Duration: 28–45 days - Random assignment to one of three EX conditions	- Duration: 4 weeks - 3 times/week, 30–40 min supervised EX - A: step-aerobic program at 60% max HR (aerobic training) - B: body-building program (anaerobic strength training) - C: circuit training (mixed aerobic and anaerobic training)	None	- No drug-related outcomes reported - No fitness gains in either group after 4 weeks - Significantly reduced depression scores in group B (bodybuilding), no changes in groups A and C - No changes in blood pressure or resting pulse	- Small N - Heterogeneity and lack of clarity concerning the diagnoses - Initial differences between groups concerning depression scores → significant reductions in group B possibly explained by higher initial scores - Training in group B in teams of 2-3, in A and C alone → social confounds - EX duration too short to improve fitness - Lack of intention-to treat analysis to correct for high number of dropouts - No follow-up data reported
Williams (2000) [40]	- N = 20 “asymptomatic offenders” (m, f) consuming metamphetamine, alcohol, cannabis, or other drugs - (diagnoses not specified) - Mixed sample (70% Caucasian, 20% Hispanic, 5% Afro-American, 5% native American)	- Outpatient community-based treatment program with 2 weekly sessions for relapse prevention - Duration: 12 weeks	- Duration: 12 weeks - Daily journals recording PA and optional 2 times/week of supervised muscle strengthening training	- None - post hoc comparison between program “completers” and “non-completers”	- No drug-related outcomes reported - “Completers” more involved into EX behavior even before the treatment - Subjects agreed that EX was effective in preventing them from relapse	- Very small N (9 dropouts), no meaningful statistic - No group assignment, no control group - Post hoc classification possibly confounded with other variables (EX adherence and abstinence may depend on the same external factors; causality is not given) - Self-selection of participants
Li et al. (2002) [41]	- N = 86 heroin-dependent patients (m) - Ethnicity not reported	- Mandatory inpatient treatment (detoxification) - Duration: 1–3 months	- Duration: 10 days - 4-5 times/day - 25–30 min Pan Gu Qigong	- A: 10 days of medication with lofexidine HCl - B: detoxification without special treatment except for PRN medication against severe withdrawal symptoms	- Fewer withdrawal symptoms and earlier negative morphine test in Qigong group - Fewer symptoms of anxiety in Qigong group compared to control groups A and B	- Ethical problems (mandatory treatment) - Lack of specific EX intervention (multifaceted intervention) - Cultural specificity of Pan Gu Qigong (lack of generalizability) - Initial group differences on day 1 concerning withdrawal symptoms → faster reductions possibly explained by lower initial scores - No follow-up data for postacute phase reported
Roessler (2010) [42]	- Pilot study N = 38 patients dependent of cannabis, opiate, medication, heroine, cocaine, and/or amphetamine (m, f) - Ethnicity not reported	- Day clinic for substance dependent patients, - (type of treatment not reported) - Duration: 2 and 6 months, respectively	- Duration: 2 and 6 months, respectively - 3 times/week 2h of endurance training, strengthening EX, and team sports (badminton, volleyball)	None	- Improvements in subjective control, craving, role of the substance - Significantly improved fitness at end of treatment - subjective reports: increased fitness reduces withdrawal symptoms and improves body perception, vigor, sleep quality, and self-confidence	- Very small N, very high dropout rates (N = 17 for pre-post comparison) - Sample selected by clinic staff based on physical condition, compliance, and so forth. - Lack of control group → changes cannot be attributed to EX - No validation of self-reported substance use
Brown et al. (2010) [43]	- Pilot study N = 16 untrained patients dependent of alcohol, cannabis, cocaine, opiates, and/or sedatives (m, f) - Mixed sample (81% Caucasian, 13% Afro-American, 6% Hispanic)	- Different concurrent treatments for substance use (inpatient, outpatient, day-clinic, individual sessions with psychiatrists) - Duration: not standardized	- Duration: 12 weeks - 1 supervised and 2-3 individual training sessions per week, progressively 20–40 min of moderate aerobic training (55–69% max HR) - 1 brief weekly CBT intervention to increase motivation for PA - incentive component for EX adherence	None	- At end of treatment, 66% of patients abstinent, with significantly lower relapse rates in patients who had attended at least 75% of EX sessions - Significantly increased fitness after 12 weeks	- Very small N, high dropout rate - Lack of control group → changes cannot be attributed to EX alone - EX adherence and abstinence may depend on the same external factors (causality not given)
Buchowski et al. (2011) [44]	- Pilot study N = 12 untrained cannabis-dependent patients not seeking treatment for their cannabis dependence - Ethnicity not reported	None	- Duration: 2 weeks - 5 times/week supervised training session (total of 10) - 30 min moderate treadmill walking/ running	None	- Cannabis consumption significantly reduced compared to baseline during intervention and at 2-week followup - Significantly reduced craving after each training session	- Very small N - Lack of control group, no substance-related intervention - EX duration too short to improve fitness - Only self-report of cannabis consumption - Motivation of patients unclear: ostensibly no desire for change concerning cannabis consumption, but very high adherence rates

AA: alcoholics anonymous, ACSM: American College of Sports Medicine, CBT: cognitive-behavioral therapy, EX: exercise, f: female, h: hour(s), HR: heart rate, HR-R: heart rate reserve, m: male, max HR: maximum heart rate, min: minutes, N: sample size, PA: physical activity.