EFFECTS OF EXERCISE REHABILITATION IN PATIENTS WITH LONG COVID-19

Abstract Moving from the first COVID–19 pandemic to the chronic phase of COVID–19, more than 50 long–term detrimental effects have been recognized in the so–called long COVID–19 syndrome. The exact mechanisms underlying the exercise capacity reduction and functional limitations are unknown, however, rehabilitation could play a pivotal role. The aim of this study was to evaluate whether a combination of aerobic and resistance training performed in the same session for 8 weeks could be well–tolerated and effective in long COVID–19 patients with reduced exercise capacity [(<85% of predicted peak aerobic capacity (VO2peak)] at 3–month from hospital discharge after COVID–19. The exercise training program included 3 exercise sessions per week. Each session included: a) aerobic exercise (starting at 30 min and increasing to 60 min) with 5 min warm–up and 5–min cool down; b) nine major muscle group resistance exercises (for the lower extremity: leg extension/flexion, abduction/adduction, and leg press; for the upper extremity: push–up/pull–down; for the core muscles: abdomen, back). The intensity of aerobic exercise was defined according to VO2peaktest results targeting the 80% level of lactate threshold in Watts. Resistance training load was determined for each muscle groups according to the results of the maximal dynamic strength testing (1RM; one repetition maximum) and was confirmed and updated after 4 weeks by defining new 1RM values. Resistance training prescription loading was defined as 40% of 1RM, 2 sets (3 sets for last two weeks) and 12 repetitions for each muscle group. The duration of a single training session was approximately 90 min. Out of 220 patients screened, 50 patients (aged 55.8±9.7 years, 15 women, body mass index 26.6±5.2 kg/m2) were enrolled. Mean exercise training sessions was 66.1±34.0; none of the patients dropped out from the study. VO2peak increased 15% and peak ventilation 9% (p < 0.001 for both). After the training program, mean percentage of VO2peak significantly increased (+14.2%, p < 0.001). Muscle strength increased markedly for all major muscle groups ranging from 16% to 33% increase (p < 0.010). An exercise rehabilitation with combined aerobic and resistance exercises for 8 weeks increases markedly both cardiorespiratory and musculoskeletal fitness in long COVID–19 patients. These results may highlight the importance of regular exercise rehabilitation aiming to promote daily activities, independent living, and better quality of life.