Table 2.

Plasma antioxidants parameters and oxidative stress of the subjects, as measured by HPLC

	50 km		80 km
	Before	After	Before	After
UA, mg/liter	77  ± 3	96  ± 3	90  ± 5	123  ± 4
AA, mg/liter	12.1  ± 0.8	13.3  ± 0.9	13.3  ± 0.9	14.4  ± 1.0
TAA, mg/liter	13.2  ± 0.9	14.6  ± 0.1	15.0  ± 1.0	15.9  ± 1.1
DHAA, mg/liter	1.2  ± 0.19	1.34  ± 0.21	1.33  ± 0.18	1.41  ± 0.19
OSAA, %	8.8  ± 1.0	8.9  ± 1.1	8.7  ± 1.1	9.4  ± 1.3

Two-tailed paired t test. Data are given as values ± SE. The differences between [UA] “Before” and “After” each march are significant (P < 0.0001). Other changes are nonsignificant. The differences of [UA] values between the beginning of the 80-km march and the beginning of the 50-km march are significant (P < 0.02). UA, AA, TAA (total ascorbic acid), and DHAA (dehydro-ascorbate) were measured by HPLC coupled with electrochemical detection, and values of the OSAA were calculated, before and after marches of 50 and 80 km, which were separated by 2 weeks. OSAA is defined as the ratio between DHAA and TAA.