The aim of this dissertaion is to assess the validity and reliability of the Chester Treadmill Walk test (CTWT) for the prediction of aerobic capacity. Four males and three females aged 25.1 (±3.3) years old that were active and healthy volunteered to take part in this study. The CTWT was carried out on two separate days and on the third occasion participants completed a maximal test called the Bruce Protocol treadmill test. Each day of testing was separated by no longer than seven days. Heart rate and RPE were measured during the sub-maximal testing and heart rate, RPE and VO2 were measured during the maximal testing. The bias ±95% limits of agreement technique was used to assess the validity of the CTWT against the maximal testing. No significant differences were found between trial one and maximal testing (0.226) and between trial two and maximal testing (0.252). The CTWT showed over-estimations in VO2max in trial one and trial two by 4.0±15.4 ml•kg-1•min-1 and 4.8±19.7 ml•kg-1•min-1 respectively. Trial one, two and maximal testing obtained VO2max mean values of 49.5±7.8, 50.3±8.4 and 45.5±10.7 ml•kg-1•min-1 respectiviely. 95% LoA technique found an over-estimation of HRmax by 6.4±14.6 beats/min, woth no significant difference found (0.062). ICC and 95% LoA techniques were used to assess VO2 (-0.8±5.2 ml•kg-1•min-1), HR (3.0 ±2.8bpm) and RPE (-0.2±0.6) reliability between trial one and trial two. ICC of 0.95, 0.99 and 0.99 were found between trial one and two in VO2, HR and RPE respectively. It is questionable whether or not the CTWT is a valid sub-maximal test to conduct, however it was found to be a reliable test. VO2max was over-estimated in both trials when compared to actual VO2max but positive relationships were found between the HR and RPE values in trial one and trial two
