Abstract Background A significant proportion of people who have had a SARS-CoV-2 infection suffer from persistent symptoms for more than three months, referred to as post-COVID-19 condition (PCC). Chronic fatigue syndrome (CFS) is common in people with PCC. Little is known about the use of therapeutic measures for people with CFS, and the effect of active exercise in particular is a subject of controversial debate. Methods From November 2023 to January 2024, an online survey was conducted among a random sample of statutorily-insured people with PCC (ICD10 U09.9). Patients with CFS were identified using the DSQ-PEM. The utilization of various physical, psychological and alternative medical therapies and their subjective effectiveness on a scale from 1 (significantly worsened) to 5 (significantly improved) were recorded. Mann-Whitney-U-tests were carried out. Results Preliminary analyses of 1,699 participants with persisting PCC revealed an indication for CFS in 310 participants. Looking at the active exercises, there is no difference in the utilization of functional training between people with and people without CFS (14.6 % vs. 14.5 %, p = 1.0), while rehabilitation sport is utilized significantly more frequently by people with CFS (26.5% vs. 18.7%, p = 0.003). While 45-48% of CFS patients benefited from active therapies, 20-30% showed a worsening of their symptoms. On average, people with CFS also showed significantly less improvement from rehabilitation sports (M 3.28 vs. 3.72, p = 0.002) and functional training (M 3.16 vs. 3.81, p = 0.002) than people without CFS. Conclusions People with CFS due to PCC are significantly more likely to utilize therapeutic services than people with PCC without CFS. Active therapies seemed to benefit almost half of CFS patients but led to worsening of symptoms in up to 20-30%. Further studies are needed to provide evidence-based treatment recommendations for this vulnerable population. Key messages • People with PCC and CFS benefit less from active therapies than people with PCC without CFS. Utilization of active therapies worsen symptoms in a relevant minority of 20-30% of CFS patients. • Further research should focus on evidence-based treatment recommendations for people with PCC and CFS.