Freire, Ana Paula Coelho FigueiraAmin, ShaanLira, Fabio SantosMorano, Ana Elisa von AhPereira, TelmoCoelho-E-Silva, Manuel-JoãoCaseiro, ArmandoChristofaro, Diego Giulliano DestroSantos, Vanessa Ribeiro dosJúnior, Osmar MarchiotoPinho, Ricardo AurinoSilva, Bruna Spolador de Alencar2023-01-312023-01-312023-01-27Freire, A.P.C.F.; Amin, S.; Lira, F.S.; von Ah Morano, A.E.; Pereira, T.; Coelho-E-Silva, M.-J.; Caseiro, A.; Christofaro, D.G.D.; Dos Santos, V.R.; Júnior, O.M.; et al. Autonomic Function Recovery and Physical Activity Levels in Post- COVID-19 Young Adults after Immunization: An Observational Follow Up Case-Control Study. Int. J. Environ. Res. Public Health 2023, 20, 2251. https://doi.org/10.3390/ijerph2003225 11660-4601http://hdl.handle.net/10400.26/43486Coronavirus disease 2019 (COVID-19) has detrimental multi-system consequences. Symptoms may appear during the acute phase of infection, but the literature on long-term recovery of young adults after mild to moderate infection is lacking. Heart rate variability (HRV) allows for the observation of autonomic nervous system (ANS) modulation post-SARS-CoV-2 infection. Since physical activity (PA) can help improve ANS modulation, investigating factors that can influence HRV outcomes after COVID-19 is essential to advancements in care and intervention strategies. Clinicians may use this research to aid in the development of non-medication interventions. At baseline, 18 control (CT) and 20 post-COVID-19 (PCOV) participants were observed where general anamnesis was performed, followed by HRV and PA assessment. Thus, 10 CT and 7 PCOV subjects returned for follow-up (FU) evaluation 6 weeks after complete immunization (two doses) and assessments were repeated. Over the follow-up period, a decrease in sympathetic (SNS) activity (mean heart rate: p = 0.0024, CI = −24.67–−3.26; SNS index: p = 0.0068, CI = −2.50–−0.32) and increase in parasympathetic (PNS) activity (mean RR:p = 0.0097, CI = 33.72–225.51; PNS index: p = 0.0091, CI = −0.20–1.47) were observed. At follow-up, HRV was not different between groups (p > 0.05). Additionally, no differences were observed in PA between moments and groups. This study provides evidence of ANS recovery after SARS-CoV-2 insult in young adults over a follow-up period, independent of changes in PA.engPost-acute sequelae of COVID-19Communicable diseasesCOVID-19SARS-CoV-2ExerciseAutonomic nervous systemSympathetic nervous systemParasympathetic nervous systemCOVID-19 vaccinationSequelas pós-agudas de COVID-19Doenças transmissíveisExercício físicoSistema nervoso autónomoSistema nervoso simpáticoSistema nervoso parassimpáticoVacinaçãojournal articledoi.org/10.3390/ijerph2003225 1