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Table 2 Results of exercise test by participant

From: Submaximal exercise testing with near-infrared spectroscopy in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome patients compared to healthy controls: a case–control study

  CFS cases (N = 16) Healthy controls (N = 16) P value case vs. control
Test length (s) 177.1 (176.1;177.5) 176.3 (175.9;177.4) 0.60
TTI (Newton-seconds) 11,388 (8,463;13,934) 15,382 (12,921;16,974) 0.008
Borg at rest* 1.5 (1;2) 0 (0;0) <0.0005
Borg at end*,** 3 (3;4) 2.5 (1.5;3) 0.01
dHHb (AU) 4.3 (3.4;10.4) 15.3 (9.1;24.2) 0.008
dHHb/dtHb (AU) 0.8 (0.6;1.5) 1.9 (1.2;3.3) 0.04
dHHb/TTI (AU/Newton-seconds) 0.0004 (0.002;0.001) 0.0009 (0.0006;0.002) 0.06
dO2Hb (AU) 0.2 (−4.2;1.4) −6.7 (−12.9;−3.6) 0.004
dO2Hb/dtHb (AU) 0.2 (−0.5;0.4) −0.9 (−2.3;−0.2) 0.04
dO2Hb/TTI (AU/Newton-seconds) 0.00002 (−0.0005;0.0001) −0.0005 (−0.001;−0.003) 0.02
dtHb (AU) 5.2 (2.1;6.9) 9.8 (0.8;13.6) 0.31
dtHb/TTI (AU/Newton-seconds) 0.0005 (0.0002;0.0008) 0.0006 (0.00006;0.0009) 1.000
  1. Results are N (%) for discrete variables or Median (IQR) for continuous and ordinal variables. dO 2 Hb Delta-oxy-hemoglobin, dHHb delta-deoxy-hemoglobin, dtHb delta-total hemoglobin, AU arbitrary unit and TTI tension-time index.
  2. P values are univariate exact test for discrete variables and rank sum for continuous and ordinal variables. Significant P values are indicated in italics. Confidence intervals not provided due to non-parametric analyses.
  3. * Ordinal variable
  4. ** One CFS case did not report Borg at 3 min due to lightheadedness and the need to quickly lie supine.