ABSTRACT After infection with SARS-CoV-2, up to 50% of individuals experience post-acute sequelae of COVID-19 (PASC) including symptoms such as fatigue, postexertional malaise, and autonomic dysfunction that can disrupt engagement in physical activity. Exercise physiologists, personal trainers, and fitness instructors need evidence-based practical training approaches to help individuals with PASC safely and effectively resume a physically active lifestyle. In this paper, we propose the Adapted Flexible Nonlinear Periodization model (AFNLP), a novel individualized approach to supporting recovery for people with PASC seeking training guidance in a fitness environment. The model, guided by emerging literature and interdisciplinary clinical experience, was developed to improve symptom management and physical recovery from PASC while reducing risk of exacerbating underlying conditions. The AFNLP framework provides a practical and flexible structure for supporting gradual return to activity and emphasizes readiness over fixed timelines. AFNLP enables symptom-responsive exercise programming that integrates physiological monitoring, nutritional support, psychological readiness, and multidisciplinary oversight. Key considerations include symptom tracking, pacing strategies, mental health, nutrition, and use of wearable technology to guide readiness-based exercise adjustments. This paper outlines the AFNLP framework and provides practitioner-oriented guidance for implementing symptom-responsive training strategies in individuals with PASC. A video abstract is available as Supplemental Digital Content 1, which provides an overview of the AFNLP framework and its application in individuals with PASC.
Scofield et al. (Mon,) studied this question.