{
  "abstract": "Background Compared to age-matched healthy individuals, people with post-COVID syndrome exhibit profoundly reduced exercise tolerance, secondary to reduced aerobic capacity.Aims To determine whether reduced aerobic capacity in previously hospitalised COVID-19 survivors is due to the diminished central cardiovascular output and/or due to the reduced capacity of the peripheral muscles to extract oxygen from the circulation during exercise.Methods Twelve previously hospitalised COVID-19 survivors (mean age: 54±9 yrs) and seven age-matched healthy controls (58±11 yrs) underwent two exercise testing laboratory visits. First, an incremental cycling test to their maximum tolerable workload to determine peak work rate (PWR). On a subsequent visit, participants undertook a single bout of constant-load exercise (CLE) sustained at a load corresponding to 80% of each participant’s PWR. The CLE test was preceded by 3 minutes of unloaded pedalling to warm up. Cardiac output (CO), heart rate, stroke volume (assessed by impedance cardiography), oxygen uptake (VO 2), and other respiratory parameters, including indices of ventilatory efficiency (VE/VO2 and VE/VCO2), were monitored throughout exercise. Arteriovenous oxygen content difference (a-vO2), which reflects how much oxygen is extracted from the blood by the muscles during exercise, was calculated by rearranging the Fick equation where VO2 = CO x (a-vO2).Results Two-way ANOVA with repeated measures showed that compared to healthy individuals, COVID-19 survivors exhibited lower (p=0.035) VO 2 during CLE (figure 1). Whilst CO was greater (p=0.001) in COVID-19 survivors compared to healthy controls, a-VO2 was lower (p=0.01) during exercise in COVID-19 survivors compared to healthy participants (figure 1). Ventilatory efficiency indices were not different between groups.Abstract S29 Figure 1Data points (mean ±SEM) are shown for unloading pedalling (UNL) and for each of the 4-min of exercise in people with post-COVID syndrome (closed circles) and healthy participants (open circles)Conclusions Whilst central cardiovascular output and ventilatory efficiency were preserved in COVID-19 survivors during submaximal exercise, peripheral muscle oxygen extraction was diminished compared to healthy participants most likely reflecting compromised muscle vasculature and/or impaired muscle fibre oxidative capacity.",
  "authors": [
    {
      "affiliations": [
        "Department of Sports, Exercise and Rehabilitation, Northumbria University, Newcastle Upon Tyne, UK"
      ],
      "name": "S Chakraverty"
    },
    {
      "affiliations": [
        "Department of Sports, Exercise and Rehabilitation, Northumbria University, Newcastle Upon Tyne, UK"
      ],
      "name": "D Megaritis"
    },
    {
      "affiliations": [
        "Department of Sports, Exercise and Rehabilitation, Northumbria University, Newcastle Upon Tyne, UK"
      ],
      "name": "E Hume"
    },
    {
      "affiliations": [
        "Department of Sports, Exercise and Rehabilitation, Northumbria University, Newcastle Upon Tyne, UK"
      ],
      "name": "E Neto"
    },
    {
      "affiliations": [
        "Department of Sports, Exercise and Rehabilitation, Northumbria University, Newcastle Upon Tyne, UK"
      ],
      "name": "G Cucato"
    },
    {
      "affiliations": [
        "Department of Respiratory Sciences, University of Leicester, Leicester, UK"
      ],
      "name": "E Daynes"
    },
    {
      "affiliations": [
        "Department of Respiratory Sciences, University of Leicester, Leicester, UK"
      ],
      "name": "R Evans"
    },
    {
      "affiliations": [
        "Department of Respiratory Sciences, University of Leicester, Leicester, UK"
      ],
      "name": "S Singh"
    },
    {
      "affiliations": [
        "The Newcastle upon Tyne Hospitals NHS Foundation Trust, Translational and Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, UK"
      ],
      "name": "C Echevarria"
    },
    {
      "affiliations": [
        "Department of Sports, Exercise and Rehabilitation, Northumbria University, Newcastle Upon Tyne, UK"
      ],
      "name": "I Vogiatzis"
    }
  ],
  "title": "S29 Peripheral muscle oxygen extraction is compromised during submaximal exercise in previously hospitalized COVID-19 survivors",
  "uid": "f3f1e423-3174-5287-a508-c4f88690b57f"
}