Abstract
Graded exercise tests (GXT) are commonly used to assess athletes. These cause fatigue, performance declines and are very interruptive to their schedules. For a GXT to reflect athletic capacity, the subject must be motivated to perform at their highest capability. Lack of motivation will result in invalid results. The idea of a submaximal exercise test is appealing for athletes. While few submaximal time to exhaustion tests have shown to be accurate, Sassi et al. (2006) recently developed an accurate protocol to predict time to exhaustion using elite level cyclists. By analyzing blood lactate measurements at 5 and 10 minutes during a submaximal workload, time to exhaustion was accurately predicted. The purpose of our study is to validate the equation created by Sassi et al. (2006) to predict time to exhaustion on a lesser trained cyclist. One participant completed 3 submaximal exercise tests at 3 predetermined constant workloads until volitional exhaustion was reached. Blood lactate was taken at 5 and 10 minutes and analyzed via Lactate Plus Lactate analyzer. Heart rate and rate of perceived exhaustion were measured and recorded to validate that the subject reached exhaustion. Blood lactate measurements were put into the regression equation created by Sassi et al. (2006) to predict time to exhaustion. The actual time to exhaustion and predicted time to exhaustion were compared. Analysis of the comparisons were done using Spearman’ Rho. Analysis of the differences of the values were analyzed using a Bland-Altman plot. The Spearmans Rho analysis has a r value of 1, showing the values are highly correlated. Analysis of the Bland-Altman plots displayed that the measurements were all within one standard deviation, confirming the actual and predicted time to exhaustion measurements were similar. The results of this study show that the equation developed by Sassi et al. (2006) to predict time to exhaustion in an elite cyclist is also valid in a lesser trained cyclist. When compared, the actual and predicted time to exhaustion were strongly correlated (r = 1) with a 2.2% difference at moderate intensity. These results support the previous studies conclusions that blood lactate is highly correlated to exercise capabilities.