Table 5.
Raw and percent differences in metabolic equivalents between individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and matched sedentary individuals during serial cardiopulmonary exercise testing (CPET), based on re-analysis of data from Snell et al. (26).
| ME/CFS (n = 51) | Control (n = 10) | |
|---|---|---|
| CPET1 | ||
| VO2, Peak | 21.51 (4.09) 20.34–22.71 |
25.04 (4.41) 22.35–27.73 |
| METs, Peak (Calculated) | 6.15 (1.17) 5.81–6.49 |
7.15 (1.26) 6.39–7.92 |
| % Difference, Peak | −16.3% | |
| VO2, VAT | 12.74 (2.85) 11.92–13.55 |
13.83 (2.79) 12.00–15.67 |
| METs, VAT (Calculated) | 3.64 (0.81) 3.41–3.87 |
3.95 (0.78) 3.43–4.48 |
| % Difference, Peak | −8.2% | |
| CPET2 | ||
| VO2, Peak | 20.44 (4.47) 19.25–21.63 |
23.96 (4.30) 21.27–26.65 |
| METs, Peak (Calculated) | 5.84 (1.28) 5.50–6.18 |
6.85 (1.23) 6.08–7.61 |
| % Difference, Peak | −14.7% | |
| VO2, VAT | 11.36 (2.91) 10.39–12.01 |
14.12 (3.26) 12.29–15.96 |
| METs, VAT (Calculated) | 3.25 (0.83) 2.97–3.43 |
4.03 (.93) 3.51–4.56 |
| % Difference, VAT | −19.4% | |
Decremented performance was noted in individuals with ME/CFS on the second CPET at peak exertion and ventilatory anaerobic threshold, indicating the physiological correlates of post-exertional malaise. Measurements are expressed as mean (standard deviation) and 95% confidence interval. CPET, cardiopulmonary exercise test; HR, heart rate; ME/CFS, myalgic encephalomyelitis/chronic fatigue syndrome; METs, metabolic equivalents; VAT, ventilatory anaerobic threshold.