# Effects of Physical Exercise on Substance Use Disorder: A Comprehensive Review
## 3 Results
### Assessment and Impact of Physical Exercise on the Quality of Life of Individuals with SUD
#### 3.1.2 Assessment and Effects of Physical Exercise on Anxiety and Stress  
A wide variety of scales and questionnaires (up to eight different ones) have been identified for measuring anxiety. In contrast, only one tool used to assess stress has been found in the literature. The most commonly used questionnaires for measuring anxiety in populations with SUD are the \"Self-Rating Anxiety Scale\" (SAS) [63], which consists of 20 items (items 2, 5, 6, 11, 12, 14, 16, 17, 18, and 20 are scored inversely, while the remainingitems are scored directly), and the \"Beck Anxiety Inventory\" (BAI) [64], which includes 21 items scored from 0 to 4, with higher scores indicating greater levels of anxiety. The only questionnaire used in the reviewed studies for measuring stress is the \"Perceived Stress Scale\" (PSS). This tool consists of 14 items and measures how frequently, over the past 30 days, the individual perceived situations as stressful, using a Likert scale in which 0 indicates \"never\" and 4 indicates \"very often\". Positive items are scored inversely, and all items are summed up to create a total score [65]. The consequences of addiction often lead to a deterioration in mental health, including symptoms of stress and anxiety linked to prior substance use [66]. This highlights the need for psychological treatment to address these issues and related mental disorders. Physical exercise has been shown to be effective as part of traditional therapy in improving anxiety and stress in patients with SUD [11; 19; 43; 55; 61; 67]. Regarding anxiety, the two meta-analyses consulted reported similar effect sizes (\(\text{SMD}=-0.31\); \(\text{Z}=-4.11\); \(p<0.01\); \(\text{SMD}=-0.33\); \(\text{Z}=4.82\); \(p<0.01\)) [11; 45]. For stress, the latest systematic review and meta-analyses also found a significant reduction (\(\text{SMD}=-0.56\); \(\text{Z}=3.08\); \(p<0.01\)) [45]. Anxiety has been widely measured due to its relationship with quality of life, as it can be more intense in individuals with SUD, negatively impacting well-being and hindering the recovery process. Anxiety is not only a common symptom, but it is also associated with cravings and a higher likelihood of relapse, among other critical factors in individuals with SUD [68]. Anxiety, Stress, and Types of Physical Exercise in Intervention Programs  
In the current literature, the concepts of anxiety and stress are often closely linked across various studies. Furthermore, most studies analyzing the effects of physical exercise on these variables employ \"mind-body\" methodologies [26; 38; 51; 69; 70; 71], particularly Yoga [26; 38; 51; 69; 71]. A recent systematic review and meta-analysis showed that Yoga has an almost moderate effect on reducing anxiety in individuals with SUD (\(\text{SMD}=-0.48\); \(\text{Z}=4.17\); \(p<0.01\)). However, its effects on stress were inconclusive, possibly due to the inclusion of only two studies in this analysis (\(\text{SMD}=-0.61\); \(\text{Z}=1.79\); \(p=0.07\)), making it difficult to draw definitive conclusions [45]. Nevertheless, other studies have reported significant reductions in both anxiety [69; 71] and stress [26; 38] in this population following Yoga practice. Conversely, one study focusing on individuals with methamphetamine addiction found significant improvements in stress (\(p=0.026\)) but not in anxiety when comparing a Yoga program to standard treatment [72]. Thus, interventions employing mind-body therapies have demonstrated a favorable effect on reducing anxiety and stress. However, further research, particularly regarding their effects on stress, is necessary to determine their superiority over standard therapy. One study compared the effects of various types of exercise (continuous aerobic and Yoga) with standard therapy on levels of depression and anxiety, as measured using the Hospital Anxiety and Depression Scale (HADS). Within the anxiety subscale, both standard therapy and Yoga showed significant pre- to post-intervention reductions.