International Journal of Environmental Research and Public Health Article The Effects of Physical Inactivity and Exercise at Home in Young Patients with Congenital Heart Disease during the COVID-19 Pandemic Federica Gentili 1 , Giulia Cafiero 1 , Marco Alfonso Perrone 2,3, * , Massimiliano Bianco 4 , Annamaria Salvati 1 , Ugo Giordano 1 , Stefani Silva Kikina 2 , Paolo Guccione 2 , Andrea De Zorzi 2 , Lorenzo Galletti 2 , Fabrizio Drago 2 , Benedetta Leonardi 2 and Attilio Turchetta 1   Citation: Gentili, F.; Cafiero, G.; Perrone, M.A.; Bianco, M.; Salvati, A.; Giordano, U.; Silva Kikina, S.; Guccione, P.; De Zorzi, A.; Galletti, L.; et al. The Effects of Physical Inactivity and Exercise at Home in Young Patients with Congenital Heart Disease during the COVID-19 Pandemic. Int. J. Environ. Res. Public Health 2021, 18, 10065. https:// doi.org/10.3390/ijerph181910065 Academic Editors: Daniela Lucini, Ferdinando Iellamo and Massimo Pagani Received: 31 July 2021 Accepted: 20 September 2021 Published: 25 September 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). 1 Division of Sports Medicine, Bambino Gesù Children’s Hospital IRCCS, 00165 Rome, Italy; federica.gentili@opbg.net (F.G.); giulia.cafiero@opbg.net (G.C.); drsalvati@yahoo.it (A.S.); ugo.giordano@opbg.net (U.G.); attilio.turchetta@opbg.net (A.T.) 2 Department of Cardiology and Cardiac Surgery, Bambino Gesù Children’s Hospital IRCCS, 00165 Rome, Italy; stefanisilva.kikina01@icatt.it (S.S.K.); paolo.guccione@uniroma2.it (P.G.); andrea.dezorzi@opbg.net (A.D.Z.); lorenzo.galletti@opbg.net (L.G.); fabrizio.drago@opbg.net (F.D.); benedetta.leonardi@opbg.net (B.L.) 3 Department of Cardiology and University Sports Centre, University of Rome Tor Vergata, 00133 Rome, Italy 4 Unità Operativa Complessa di Medicina dello Sport e Rieducazione Funzionale, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Università Cattolica del Sacro Cuore, 00168 Rome, Italy; massimiliano.bianco@policlinicogemelli.it * Correspondence: marcoalfonso.perrone@opbg.net or marco.perrone@uniroma2.it Abstract: Background: The COVID-19 pandemic had a significant impact on the population’s ability to be physically active. Purpose: Evaluate the effect of the COVID-19 mitigation measures on exercise tolerance in patients with congenital heart disease (CHD). Materials and methods: All subjects (880, 6–18 years old) who performed a stress test at our hospital from October 2020 to February 2021 and had a similar test one year earlier were enrolled. A questionnaire on the degree of physical activity carried out in 2020 concerning the period prior to the pandemic was compiled. Exercise tolerance and the main anthropometric parameters between the first and second tests were compared. Results: 110 subjects (11.9 ± 4.1 years) were included in the study. The percentage of patients engaged in regular physical activity (RPA) decreased significantly during the pandemic (p < 0.001), and BMI increased significantly (p < 0.001), except among the subjects who began RPA during the lockdown, whereas test duration did not decrease significantly overall but increased in this last subgroup (p < 0.05) Conclusions: The COVID-19 lockdown led to a less active lifestyle with a significant increase in BMI in our group of CHD. These data could have negative effects on the risk profile of this population. RPA practiced at home seems to be effective in counteracting such effects. Keywords: congenital heart disease; COVID-19; exercise training; physical activity 1. Background Coronavirus disease 2019 (COVID-19) is an ongoing pandemic caused by the se- vere acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has infected nearly 200 million people worldwide so far [1–3]. On 30 January 2020, the World Health Organization (WHO) declared the COVID-19 epidemic a global health emergency, and on 11 March 2020, the disease was declared a global pandemic [1]. The consequences in terms of human lives and hospital admissions have been dramatic [2,3]. In fact, to date, more than 4 million people have died in the world from the coronavirus outbreak [2]. In order to limit the spread of the virus and the saturation of intensive care units, measures have been taken to confine individuals to their homes and to promote social distancing. As a result, gyms, public parks, sports fields, outdoor play areas, and schools, as Int. J. Environ. Res. Public Health 2021, 18, 10065. https://doi.org/10.3390/ijerph181910065 https://www.mdpi.com/journal/ijerph