INTRODUCTION: Physical activity (PA) holds a pivotal role in the improvement of mental health or depressive symptoms, as well as in the prevention of cardiovascular diseases (CVDs). Patients with SLE are exposed to an increased risk of CVDs and suffer from deteriorated quality of life compared with the general population. The aim of this study was to assess PA level and characteristics in a large international cohort of patients with SLE. METHODS: PA was assessed in metabolic equivalent of tasks (METs) using the International Physical Activity Questionnaire (IPAQ) and classified into three levels: low, moderate and high PA. Other data such as fatigue, disease activity, pain, insomnia, anxiety, depression, stress and fibromyalgia were collected using validated patient-reported instruments, using the Lupus Expert system for the Assessment of Fatigue (LEAF) digital tool. RESULTS: 1029 LEAF participants with SLE (986 (95.8%) women) with a median age of 43 years were analysed. The median physical expenditure was 936 METs/week (IQR: 297-2622). 456 (44.3%) participants were classified as having low PA levels. Increased fatigue according to the Functional Assessment of Chronic Illness Therapy-Fatigue Scale (p<
0.0001), the Multidimensional Fatigue Inventory (p<
0.0001), Visual Analogue Scale for fatigue (p=0.02), pain (p=0.009), depression (p=0.02) and stress (p<
0.0001) were significantly more prevalent in less active patients, in IPAQ classification. CONCLUSION: In this large international study, more than 40% of patients with SLE were not active enough. We found an inverse association between PA levels and fatigue, pain, stress or depression. This points out the necessity to better assess PA in patients with SLE, as well as the aforementioned comorbidities to improve quality of life and reduce cardiovascular risk.