Table 3.

Aerobic fitness at baseline and discharge (VO₂max estimated from Åstrand nomogram and % from normal) in all patients and in patients with specific back pain (SBP), non-specific back pain (N-SBP) and widespread pain (WSP)

	All subjects		SBP		N-SBP		WSP
	Female n = 48	Male n = 46	Female n = 9	Male n = 10	Female n = 26	Male n = 29	Female n = 13	Male n = 7
Aerobic fitness—baseline
VO2max estimated (ml/kg)	27.8	29.7	26.0	28.4	26.5	30.7	31.2	27.4
Percentage of normative data	86.7	74.6	80.1	72.0	84.7	76.4	95.2	71.2
Aerobic fitness—discharge
VO2max estimated (ml/kg)	30.2	33.6	27.5	31.2	29.2	35.1	33.9	30.8
Percentage of normative data	95.0	80.4	87.2	80.5	94.2	81.2	102.0	77.2
P-value—gender difference	0.004		0.346		0.228		0.029
P-value—sub-diagnosis difference	0.259	0.498
P-value—compared to normal (=100)	0.000	0.000	0.057	0.000	0.000	0.000	0.397	0.000
Pearson correlation coefficient
Aerobic fitness—pain duration	−0.081		−0.005		−0.156		0.102
P-value—correlation—pain duration	0.445		0.985		0.261		0.669

P-values for group differences in aerobic fitness at baseline concerning gender, diagnostic sub-group and compared to normal. Pearson correlations between aerobic fitness and pain duration at baseline