# Effects of Physical Exercise on Substance Use Disorder: A Comprehensive Review
## 1 Introduction  
Substance use disorder (SUD) represents a global public health issue with significant social and healthcare implications. According to the United Nations Office on Drugs and Crime and the World Health Organization (WHO), approximately 400 million individuals, that is 7% of the global population aged 15 years and older, are affected by alcohol use disorders, with another 209 million suffering from alcohol dependence [1]. Globally, more than 60 million people engage in the use of opioids, with opioid dependence contributing to a significant proportion of drug-related deaths. Stimulant drugs, including cocaine and amphetamines, are used by over 35 million people, presenting challenges related to dependence and associated health complications [2]. The consequences of substance usedisorders extend beyond the individual level, placing an enormous burden on healthcare systems, reducing workplace productivity, and affecting the overall social fabric worldwide. Research indicates a significant relationship between substance dependence, mental health, and quality of life (QOL). Studies have found high prevalence rates of depression, anxiety, and hopelessness among individuals with SUD, which have a negative impact on their QOL [3,4]. These findings highlight the importance of considering psychological factors when assessing and improving the QOL for individuals with chronic conditions, including SUD [5, 6, 7]. Traditional therapeutic interventions for SUD have primarily included pharmacological treatments and psychological therapies, both individual and group-based. However, there has been a growing interest in recent decades in incorporating complementary interventions that can enhance the outcomes of conventional treatment [8]. According to the WHO, physical exercise is defined as a subtype of physical activity that is structured, planned, and repetitive. Its application in such interventions has emerged as a promising tool, supported by preliminary scientific evidence suggesting benefits at both neurobiological and psychosocial levels [9, 10, 11]. The articles reviewed, published between 2007 and 2024, reveal a growing trend in scientific production concerning the impact of physical exercise in individuals with SUD. In the first years of the analyzed period, the number of publications was limited, but from 2013 onwards, there has been a sustained increase, reaching its peak at the end of this period. This pattern reflects the increasingly consolidated focus on this area, highlighting physical exercise as an innovative and essential strategy in the recovery process for individuals with SUD. Physical exercise can be divided into several subtypes based on intensity: continuous (characterized by maintaining a constant effort over an extended period of time, typically at moderate intensity), fractionated (with work periods interspersed with short breaks), and interval-based exercise, which combines periods of high intensity with rest or lower-intensity phases, as observed in high-intensity interval training (HIIT) [12]. Exercise programs primarily feature two approaches: (a) \"mind-body\" disciplines, which integrate physical exercise, mindful breathing, and meditation techniques (such as Yoga, Tai Chi, or Qigong), typically performed at a low intensity; and (b) aerobic programs, ranging from moderate intensity to HIIT, mainly targeting improvements in cardiovascular fitness [12]. Recently, multidisciplinary programs focusing on muscle strength enhancement have gained prominence, employing resistance exercises involving large muscle groups (chest, back, core, and legs) [13, 14, 15, 16, 17, 18, 19]. However, these programs often lack methodological homogeneity and consensus, featuring insufficient descriptions and inconsistent management of key variables related to load, such as volume, intensity, frequency, and type of exercise. In the reviewed literature, their prescription is generally based on sets and repetitions [13, 15, 16] or effort duration [17].