Eight Weeks of Exercise Training Improves Fitness Measures in Methamphetamine-Dependent Individuals in Residential Treatment

Abstract

BACKGROUND: Worldwide, more than 25 million adults are estimated to be using methamphetamine (MA) and other amphetamine-type stimulants for non-medical purposes accounting for more drug abuse than heroin and cocaine combined. Although some behavioral approaches have proven beneficial, effective treatments for MA dependence still remain elusive. PURPOSE: To assess the impact of a progressive, 8-week endurance and resistance exercise training program on fitness measures in a sample of individuals in residential treatment for MA dependence. METHODS: Thirteen residential MA-dependent individuals were randomized to 3 d/week of exercise training (ET, n=7) or equal attention without training (EA, n=6) over 8 weeks. Aerobic performance (VO2max) was assessed at baseline with a symptom-limited incremental treadmill exercise test. Body composition was assessed by skinfolds. Muscle strength was measured by 1-repetition maximum (1-RM) for leg press (LP) and chest press (CP) exercises and muscle endurance was determined by repetitions to failure for LP and CP using 85% of baseline 1-RM values. ET subjects received individualized programs for endurance and resistance exercise training whereas EA subjects received one-on-one health education sessions. RESULTS: Baseline subject characteristics were matched between groups: age 32 (6) y; body weight 84 (18) kg; height 1.74 (0.08) m, mean (SD). ET subjects significantly improved VO2max by 0.62 (0.22) L/min (26%), LP strength by 23.7 (6.2) kg (38%), CP strength by 22.1 (5.1) kg (51%). LP and CP endurance improved by 8 repetitions (76%) and 5 repetitions (56%), respectively. Body weight (-2.0±1.9 kg, 2%), % relative body fat (-3.6±0.9%, -23%) and fat weight (-3.4±1.9 kg, 26%) all improved significantly with ET. None of these measures changed in EA and differences in changes for each one of these variables between groups were highly significant (P<0.001). CONCLUSIONS: Individuals recovering from methamphetamine dependency in a residential facility showed impressive improvements in aerobic exercise performance, muscle strength and endurance, and body composition with a supervised training program. These findings provide the basis for investigating whether this type of exercise intervention facilitates rehabilitation from drug dependency and reduces recidivism.