Fatigue in Covid-19 survivors: The potential impact of a nutritional supplement on muscle strength and function

Background: Fatigue with reduced tolerance to exercise is a common persistent long-lasting featureamongst COVID-19 survivors. The assessment of muscle function in this category of patients is oftenneglected.Aim.: To evaluate the potential impact of a daily supplementation based on amino acids, minerals, vi-tamins, and plant extracts (Apportal®) on muscle function, body composition, laboratory parameters andself-rated health in a small group of COVID-19 survivors affected by fatigue.Methods: Thirty participants were enrolled among patients affected by physical fatigue during or afteracute COVID-19 and admitted to the post-COVID-19 outpatient service at Fondazione Policlinico Gemelliin Rome between 1st March 2021 and 30th April 2021. All participants were evaluated at first visit (t0)and at control visit (t1), after taking a daily sachet of Apportal® for 28 days. Muscle function wasanalyzed using hand grip strength test, exhaustion strength time and the number of repetitions at one-minute chair stand test. Body composition was assessed with bioelectrical impedance analysis (BIA).Laboratory parameters, including standard blood biochemistry and ferritin levels, were evaluated at thefirst visit and during the control visit. A quick evaluation of self-rated health, before COVID-19, at t0 andt1, was obtained through a visual analogue scale (VAS).Results: Participants aged 60 years and older were 13 (43%). Females represented the 70% of the studysample. Participants hospitalized for COVID-19 with low-flow oxygen supplementation represented the43.3% of the study sample while 3.3% received noninvasive ventilation (NIV) or invasive ventilation. Handgrip strength improved from 26.3 Kg to 28.9 Kg (p < 0.05) at t1 as compared to t0. The mean time ofstrength exhaustion increased from 31.7 s (sec) at t0 to 47.5 s at t1 (p < 0.05). Participants performed ahigher number of repetitions (28.3 vs. 22.0; p < 0.05) during the one-minute chair stand test at t1 ascompared to t0. A trend, although not significant, in reduction of ferritin levels was found after nutri-tional supplementation (94.4 vs. 84.3, respectively; p ¼ 0.01). The self-rated health status increased by atleast 13 points (t0, mean 57.6 ± 5.86; t1, mean 71.4 ± 6.73; p < 0.05).Conclusions: After 28 days of nutritional supplementation with Apportal® in COVID-19 survivors affectedby fatigue with reduced tolerance to exercise, we found a significant improvement in means of musclestrength and physical performance, associated with enhancement of self-rated health status between t0 and t.