Dissertation submitted to Luton University for the degree of Masters by ResearchOxidant production in exercise was investigated with the aim of determining whether certain
exercise intensities could cause increases in post exercise concentrations of urinary free radical
markers, when compared to pre-exercise marker concentrations, by use of a simple, easy to
repeat study. Subjects exercised at a variety of set percentages of maximum oxygen intake
capacity (V02 Max) for 30 minutes, following which urine samples were taken at scheduled time
points for up to 24 hours. Samples were analysed for markers of free radical damage to cellular
structures. No significant differences in concentrations were found between individual sample
time-points in each urinary free radical marker (p=>O.OS). However urinary concentrations of
each marker were significantly different (p=<O.OS). For all urinary markers analysed there was a
significant difference in concentrations between exercise at an intensities of 1 00% V02 Max and
85% V02 Max (p=<O.OS). Also observed was a general pattern of concentration changes over
the 24 hours, for all urinary markers. Oxidant production was also studied in a group of Free
Divers as they competed in three classes in a World Championship free dive event. Subjects
gave urine samples pre-dive and post-dive which were analysed for markers of free radical
damage to cellular structures, as before. Of the three classes studied, the Static event
consistently produced the highest concentrations of urinary markers, possibly due to a weaker
'dive reflex' response in the divers. The results of both studies demonstrate that concentrations
of urinary markers of free radical damage are unique to each individual. However, the significant
differences found between markers show that different forms and intensities of exercise
produce different magnitudes of free radical markers in the urine. Such analysis can provide
useful information into how different intensities of exercise may influence general health
