Cardiopulmonary Exercise Testing Reveals Functional Limitations and Work Disability in Severe Post-COVID-19 and ME/CFS Patients, 2026, Tomaskovic+

[forestglip]

Cardiopulmonary Exercise Testing Reveals Functional Limitations and Work Disability in Severe Post-COVID-19 and ME/CFS Patients

Spoiler: Authors

Tomaskovic, Aleksandar; Weber, Vincent; Ochmann, David T.; Hillen, Barlo; Neuberger, Elmo W. I.; Brahmer, Alexandra; Lachtermann, Ella; Lieb, Klaus; Simon, Perikles

Background
Patients severely affected by post-COVID-19 condition (PCC) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) often experience long-term work incapacity, contributing to a growing economic burden. Organ-centered clinical diagnostics frequently fail to explain their work disability.

Objectives
We aimed to objectively assess physical work ability using cardiopulmonary exercise testing (CPET) in a cohort of long-standing and severely affected PCC patients. We hypothesized: (1) patients with ME/CFS exhibit lower peak oxygen uptake (VO₂ peak [mL/min/kg]) and peak power output (PPO [W/kg]) than those without; (2) most patients demonstrate objective work disability, closely aligned with subjective perception of disability; (3) oxygen pulse (O 2 pulse [mL/bpm]) is reduced in ME/CFS, independent of comorbidity.

Methods
The study was conducted in the Department of Sports Medicine, Prevention and Rehabilitation at Johannes Gutenberg-University Mainz (Mainz, Germany). Between July 31, 2023, and March 31, 2025, a total of 92 PCC patients with suspected occupational disease underwent symptom-limited CPET and completed the Canadian Consensus Criteria, Bell Disability Scale (Bell-Score), and DePaul Symptom Questionnaire (Post-Exertional Malaise) Short Form (DSQ-PEM).

Results
Nearly half of the patients (49%) met ME/CFS criteria and 79% screened positive on the DSQ-PEM. ME/CFS patients showed significantly lower VO₂ peak (13.0 ± 3.1 vs. 15.4 ± 4.9, p = 0.012), PPO (0.9 ± 0.3 vs. 1.1 ± 0.5, p = 0.014), and O₂ pulse (7.7 ± 2.0 vs. 8.5 ± 1.9, p = 0.047) compared to those without ME/CFS.

Overall, 66% of patients met objective thresholds for work disability (VO₂ peak < 15 mL/min/kg or PPO < 1 W/kg).

Forty-five patients (51%) had a Bell-Score ≤ 30 and 82% from those had VO₂ peak < 15 and/or PPO < 1. VO₂ peak and PPO significantly correlated with Bell-Score (r = 0.3, p = 0.005 and r = 0.3, p = 0.003) and were the lowest among patients on medical sick leave (13.3 ± 3.3 and 0.9 ± 0.3), compared to those in occupational reintegration (16.0 ± 3.9, p = 0.04 and 1.2 ± 0.5, p = 0.024) or currently working (18.0 ± 7.1, p = 0.036 and 1.2 ± 0.5, p = 0.015).

Conclusions
Severely affected PCC patients exhibit objective work disability, particularly those with ME/CFS. VO₂ peak and PPO are associated with subjective disability and occupational status.

Therefore, early integration of CPET into clinical and occupational evaluations can inform individualized therapy planning and return-to-work decisions.

Trial registration
DRKS, DRKS00032394. Registered 28 July 2023, https://drks.de/search/de/trial/DRKS00032394

Web | DOI | PDF | Sports Medicine - Open | Open Access

 

[Turtle]

This is really bad.

The first study like this and I hope it will be the last.

All in the name of wanting proof before disability can be given.

The German drill-sergeant-rehabs are at it again.

79% screened positive on DSQ-PEM and they still went ahead.
Payed for by Berufsgenossenschaft für Gesundheitsdienst ubd Wohlfahrtspflege. Occipation club for Health and Welfare Care (my translation)

@dave30th the german patients need you.

 

[dave30th]

the german patients need you.

in the end, can these results be used to help people seeking disability?

 

[Turtle]

in the end, can these results be used to help people seeking disability?

Yes and also denied disability, but at what cost?

 

[Utsikt]

Competing Interests​

Aleksandar Tomaskovic, Vincent Weber, David T. Ochmann, Barlo Hillen, Elmo W.I. Neuberger, Alexandra Brahmer, Ella Lachtermann, Klaus Lieb, and Perikles Simon declare that they have no competing interests.

Perikles has said in a public presentation that he initially encountered LC patients when he was contacted by an insurance company to assess their ability to work.

That sounds like a conflict of interests to me.

 

[dave30th]

es and also denied disability, but at what cost?

Right--I meant would the results help overall to give credibility to the notion that people are actually seriously disabled. Not to the idea that people should have to get CPETs in each case to prove it.

 

[Turtle]

Right--I meant would the results help overall to give credibility to the notion that people are actually seriously disabled. Not to the idea that people should have to get CPETs in each case to prove it.

Thanks for explaining.
I got my disability because of CPET, but even the chance that some patients could get even more disabled because of CPET is horrible.
The authors seem to want to use CPET earlier on, that sounds to me on all patients.

 

[Utsikt]

Right--I meant would the results help overall to give credibility to the notion that people are actually seriously disabled. Not to the idea that people should have to get CPETs in each case to prove it.

The paper is pushing hard for using CPET to prove disability.

 

[RainbowCloud]

I’m severe and there’s no way I could participate in something like this. I can barely leave my bed let alone the house so I can’t understand how on earth it’s possible to do a CPET study in people with severe ME. This does not add up at all for me.

 

[dave30th]

The paper is pushing hard for using CPET to prove disability.

got it.

 

[RainbowCloud]

I don’t have enough juice to read the study but just wanted to add a thought that if this study doesn’t address PEM (it doesn’t sound like it is) then it’s missing one the of the defining features of ME.

Even if they did a two CPETs 24hrs apart, it could miss those whose PEM hits after 2 or 3 days.

 

[SNT Gatchaman]

I meant would the results help overall to give credibility to the notion that people are actually seriously disabled. Not to the idea that people should have to get CPETs in each case to prove it.

There are limitations with respect to BMI and comorbidities, but they emphasised peripheral physiological limitations, especially oxygen uptake.

Oxygen uptake efficiency during exercise was impaired, as indicated by an OUES of 579.2 ± 154.4 mL/min and by a reduced O2 pulse at VT1 (7.5 ± 1.7 mL/bpm), VT2 (8.4 ± 1.8 mL/bpm), and exhaustion (8.1 ± 2 mL/bpm). PCC patients with ME/CFS demonstrated a significantly lower O2 pulse at VT1 (7.1 ± 1.6 vs. 7.8 ± 1.7 mL/bpm, p = 0.043)

PCC patients with ME/CFS exhibited significantly lower VO₂ peak and PPO [Peak Power Output] as well as markedly diminished O₂ pulse values adjusted for sex, age, and body mass. These impairments cannot be explained by the presence of comorbidities or deconditioning alone and support the hypothesis that peripheral functional limitations, likely driven by impaired systemic oxygen extraction rather than central structural organ abnormalities, represent a predominant physiological mechanism.

In addition to the markedly reduced physical capacity observed across the PCC cohort, patients exhibited a pronounced abnormal ventilatory response. Abnormalities in ventilatory efficiency were pervasive. The mean VE/VCO₂ slope was elevated at 37.7 ± 9.0, with 92% of patients exceeding the pathological threshold of 30. In addition, nearly all patients (95%) had resting PETCO₂ values below 36 mmHg, averaging 30.9 ± 3.3 mmHg, and one-third (34%) exhibited a blunted PETCO₂ response to exercise (< 3 mmHg increase). Ventilatory equivalents at peak load were also elevated (VE/VO₂: 38.2 ± 8.4; VE/ VCO₂: 36.1 ± 5.8), reinforcing the presence of dysfunctional ventilatory regulation under stress.

Importantly, objective signs of cardiopulmonary impairment at rest were rare in this cohort. Only 10% of patients demonstrated pulmonary limitation on body plethysmography (FVC < 50% in six; FEV₁ < 40% in three), and no pathological findings were observed on resting ECGs. This argues against structural cardiopulmonary disease as the primary cause of exercise intolerance.

Instead, several parameters suggest impaired systemic oxygen extraction as key limiting mechanisms.

Further evidence of impaired oxygen uptake efficiency was provided by mean OUES, which was 579.2 ± 154.4 mL/min. This was markedly lower than the expected values for healthy individuals and indicated inefficient ventilatory response to increasing metabolic demand . Together, these findings suggest that functional limitations in this cohort are primarily driven by suboptimal oxygen uptake efficiency rather than central cardiac or pulmonary pathology. This aligns with prior studies

Most patients (66.3%) had a VO2peak < 15 mL/min/kg and/or a PPO < 1 W/kg, indicating absolute work disability, which was strongly associated with self-reported functional limitations and current occupational status.

In an ideal world that latter statement could simply allow for the self-report to qualify for disability support. But there's a moral panic around disability freeloading. I'm sure that could be easily overcome with wearable technology of course: eg I have multi-year data that shows exactly how much I now move about with cardiac responses, and nobody attempting a fraud is going to easily reproduce that level of data. (Even the old-fashioned investigator parked in a car across the road with a camera is going to be bored as hell, I simply barely leave the house and when I do it looks painfully limited).