Table 5.

Age, anthropometric, blood and urine characteristics of the 24-hr ultra-runners (n = 12)

	Pre-race	Post- race	Change in absolute	Change in percent	P-value
Male 24-hr ultra-runners (n = 8)
Age (yrs.)	37.5 ± 8.1
Body mass (kg)	71.1 ± 5.9	70.0 ± 6.7	−1.1 ± 1.2*	−1.6 ± 1.8*	<0.05
Plasma sodium (mmol/L)	140.1 ± 1.2	139.1 ± 2.0	−1.0 ± 2.3	−0.7 ± 1.7	0.26
Plasma potassium(mmol/L)	6.7 ± 1.1	5.1 ± 0.6	−1.6 ± 1.3*	−21.8 ± 17.4*	<0.05
Plasma creatinine (mg/dL)	0.9 ± 0.1	0.9 ± 0.2	0.0 ± 0.1	10.6 ± 12.7	0.06
Plasma creatine kinase (U/L)	224.0 ± 192.0	8813.8 ± 10536.4	8589.8 ± 10500.7*	5782.1 ± 8659.2*	<0.05
Plasma creatine clearance (ml/min)	10657.2 ± 1614.2	9623.2 ± 1837.4	−1034.1 ± 1121.0*	−9.8 ± 11.7*	<0.05
Urine creatinine (mmol/L)	7.5 ± 1.3	17.5 ± 2.6	10.0 ± 2.7**	139.2 ± 47.9**	<0.01
Female 24-hr ultra-runners (n = 4)
Age (yrs.)	40.0 ± 7.7
Body mass (kg)	56.9 ± 5.2	56.3 ± 5.1	−0.6 ± 0.6	−1.0 ± 1.2	0.16
Plasma sodium (mmol/L)	139.8 ± 2.6	137.8 ± 3.4	−2.0 ± 3.4	−1.4 ± 2.4	0.32
Plasma potassium(mmol/L)	6.2 ± 0.3	4.6 ± 0.2	−1.7 ± 0.2**	−26.4 ± 2.9**	<0.01
Plasma creatinine (mg/dL)	0.7 ± 0.1	0.7 ± 0.1	0.01 ± 0.0	9.0 ± 7.3	0.18
Plasma creatine kinase (U/L)	99.0 ± 23.5	5507.1 ± 6600.4	5408.1 ± 6580.2**	4765.0 ± 4806.5**	0.19
Plasma creatine clearance (ml/min)	10353.4 ± 795.3	9547.0 ± 845.9	−806.4 ± 838.7	−7.6 ± 7.9	0.15
Urine creatinine (mmol/L)	4.5 ± 2.1	15.2 ± 0.2	10.7 ± 1.9**	327.8 ± 276.6**	<0.01

Note: Results are presented as mean ± SD; * = P < 0.05, ** = P < 0.01