Physiological response to interval training

The purpose of this study was to examine the effect of swimming distance and rest interval on the intensity of swimming (relative to VO2 max) and the contributions of the three energy systems (aerobic, anaerobic, and alactic) during these interval sets. Nine male college swimmers performed fourteen different interval training sets. Distances were 25, 50, 100, or 200 yards with rest intervals of 10 seconds, 1, and 3 minutes. During these sets only the distance to be swum and the rest interval for the set was given. No qualitative information from the coach was provided. These interval sets were performed by the swimmers with the influence from timers being kept minimal. Oxygen cost during the swim was determined from the velocity of the swim based on a linear regression for swimming velocity and oxygen uptake for each swimmer. The same interval sets were completed with pace controled where venous blood samples were obtained 1, 3, 5, and 7 minutes after the completion of each training set. 81ood samples were analyzed for lactate accumulation, blood pH, p0.,, pCO2, and hemoglobin. From these values bicarbonate, base excess, and blood oxygen saturation were calculated using equations developed by Siggard-Anderson. The results of this study do indicate that there is a predictable relationship between swimming distance and rest interval on swimming intensity (relative to VO., max). There was a curvilinear L relationship between swimming intensity (relative to VO max) and rest interval for 50, 100, and 200 yard interval sets. The correlation at these distances were r-0.96, 0.93, and 0.94 respectively. There was a linear relationship between intensity and the distance swum for the 10 second, 1, and 3 minute rest intervals. The correlation for these rest intervals were r= 0.99, 0.99, and 1.00 respectively. There was an increase in the relative contribution of aerobic energy as the distance of the swim increased for all three rest intervals. At a given swiming distance there was a greater contribution of non-aerobic energy as the rest interval increased. Contrary to continuous swimming, greater swimming velocity does not directly correspond to greater contributions of anaerobic energy during intermittent swimming. The distance and rest interval during intermittent training greatly effect the relative contributions of the three energy systems. The intensity of the swim and the relative contributions of each energy system should be considered when planning specific training regimens.Thesis (M.A.