Abstract
Caffeine is one of the most widely used psychoactive substances worldwide (WHO, 2004). A primary motivator for caffeine consumption is its cognitive and mood-enhancing benefits (Temple, Dewey, & Briatico, 2010). Cessation of caffeine consumption often results in withdrawal symptoms such as headache, decreased mood, and difficulty concentrating (Juliano & Griffiths, 2004). Aerobic exercise has been associated with the reduction of withdrawal symptoms in tobacco cessation and cognitive benefits (Chang et al., 2012; Roberts et al., 2012). The effects of aerobic exercise in comparison to caffeine on reducing withdrawal symptoms and restoring cognitive performance following caffeine deprivation remains unknown. Twenty-five caffeine consumers (>150mg/day) (Mage = 23.44 ± 3.52, 14 females, 11 males, moderate physical activity levels) underwent a baseline working memory assessment (n-back task; Owen et al., 2005) and caffeine withdrawal symptom questionnaire (CWSQ). Following a 12-hour caffeine deprivation period, participants were re-assessed on the n-back task and CWSQ, then randomized to receive either twenty minutes of aerobic exercise (40-60% Heart Rate Reserve) or caffeine administration (1.2mg/kg). Post either intervention, participants were re-assessed on the n-back task and CWSQ. Post-hoc paired t-tests indicated caffeine administration and aerobic exercise reduced caffeine withdrawal symptoms, respectively (p = 0.018, d=1.15; p = 0.617, d = 0.730). No differences were detected between baseline, deprived, and post-caffeine or post-exercise cognitive performance (p > 0.05). Findings indicate aerobic exercise demonstrates utility in reducing caffeine withdrawal symptoms induced by a 12-hour deprivation period. A longer caffeine deprivation period may be required to detect withdrawal induced cognitive decrements.
