Exercise Limitation after Critical Versus Mild COVID-19 Infection: A Metabolic Perspective.

Exercise limitation in COVID-19 survivors is poorly explained. In this retrospective study, cardiopulmonary exercise testing (CPET) was coupled with an oxidative stress assessment in COVID-19 critically ill survivors (ICU group). Thirty-one patients were included in this group. At rest, their oxygen uptake (VO2) was elevated (8 [5.6-9.7] mL/min/kg). The maximum effort was reached at low values of workload and VO2 (66 [40.9-79.2]% and 74.5 [62.6-102.8]% of the respective predicted values). The ventilatory equivalent for carbon dioxide remained within normal ranges. Their metabolic efficiency was low: 15.2 [12.9-17.8]%. The 50% decrease in VO2 after maximum effort was delayed, at 130 [120-170] s, with a still-high respiratory exchange ratio (1.13 [1-1.2]). The blood myeloperoxidase was elevated (92 [75.5-106.5] ng/mL), and the OSS was altered. The CPET profile of the ICU group was compared with long COVID patients after mid-disease (MLC group) and obese patients (OB group). The MLC patients (n = 23) reached peak workload and predicted VO2 values, but their resting VO2, metabolic efficiency, and recovery profiles were similar to the ICU group to a lesser extent. In the OB group (n = 15), no hypermetabolism at rest was observed. In conclusion, the exercise limitation after a critical COVID-19 bout resulted from an altered metabolic profile in the context of persistent inflammation and oxidative stress. Altered exercise and metabolic profiles were also observed in the MLC group. The contribution of obesity on the physiopathology of exercise limitation after a critical bout of COVID-19 did not seem relevant.

Cardiopulmonary Exercise Testing in Critically Ill Coronavirus Disease 2019 Survivors: Evidence of a Sustained Exercise Intolerance and Hypermetabolism.

To investigate exercise capacity at 3 and 6 months after a prolonged ICU stay. DESIGN: Observational monocentric study. SETTING: A post-ICU follow-up clinic in a tertiary university hospital in Liège, Belgium. PATIENTS: Patients surviving an ICU stay greater than or equal to 7 days for a severe coronavirus disease 2019 pneumonia and attending our post-ICU follow-up clinic. MEASUREMENTS AND MAIN RESULTS: Cardiopulmonary and metabolic variables provided by a cardiopulmonary exercise testing on a cycle ergometer were collected at rest, at peak exercise, and during recovery. Fourteen patients (10 males, 59 yr [52-62 yr], all obese with body mass index > 27 kg/m2) were included after a hospital stay of 40 days (35-53 d). At rest, respiratory quotient was abnormally high at both 3 and 6 months (0.9 [0.83-0.96] and 0.94 [0.86-0.97], respectively). Oxygen uptake was also abnormally increased at 3 months (8.24 mL/min/kg [5.38-10.54 mL/min/kg]) but significantly decreased at 6 months (p = 0.013). At 3 months, at the maximum workload (67% [55-89%] of predicted workload), oxygen uptake peaked at 81% (64-104%) of predicted maximum oxygen uptake, with oxygen pulse and heart rate reaching respectively 110% (76-140%) and 71% (64-81%) of predicted maximum values. Ventilatory equivalent for carbon dioxide remains within normal ranges. The 50% decrease in oxygen uptake after maximum effort was delayed, at 130 seconds (115-142 s). Recovery was incomplete with a persistent anaerobic metabolism. At 6 months, no significant improvement was observed, excepting an increase in heart rate reaching 79% (72-95%) (p = 0.008). CONCLUSIONS: Prolonged reduced exercise capacity was observed up to 6 months in critically ill coronavirus disease 2019 survivors. This disability did not result from residual pulmonary or cardiac dysfunction but rather from a metabolic disorder characterized by a sustained hypermetabolism and an impaired oxygen utilization.

Biomechanical analysis of abdominal injury in tennis serves. A case report.

The serve is an important stroke in any high level tennis game. A well-mastered serve is a substantial advantage for players. However, because of its repeatability and its intensity, this stroke is potentially deleterious for upper limbs, lower limbs and trunk. The trunk is a vital link in the production and transfer of energy from the lower limbs to the upper limbs; therefore, kinematic disorder could be a potential source of risk for trunk injury in tennis. This research studies the case of a professional tennis player who has suffered from a medical tear on the left rectus abdominis muscle after tennis serve. The goal of the study is to understand whether the injury could be explained by an inappropriate technique. For this purpose, we analyzed in three dimensions the kinematic and kinetic aspects of the serve. We also performed isokinetic tests of the player's knees. We then compared the player to five other professional players as reference. We observed a possible deficit of energy transfer because of an important anterior pelvis tilt. Some compensation made by the player during the serve could be a possible higher abdominal contraction and a larger shoulder external rotation. These particularities could induce an abdominal overwork that could explain the first injury and may provoke further injuries. Key pointsIn the proximal-distal sequence, energy is transmitted from lower limbs to upper limps via trunk.The 3D analysis tool is an indispensable test for an objective evaluation of the kinematic in the tennis serve.Multiple evaluations techniques are useful for fuller comprehension of the kinematics and contribute to the awareness of the player's staff concerning pathologies and performance.