Can Cognitive Training During Exercise Improve Performance On A Time To Exhaustion (TTE) Test?

Abstract

Mental fatigue can negatively affect our drive to continue exercise. A recent study showed that a training intervention combining exercise and a cognitive task was able to improve performance on a time to exhaustion (TTE) test, which is a challenging task where individuals are required to exercise at a set workload for as long as possible. The duration of the training needed to improve TTE is unknown. PURPOSE: To determine if an 8-week cognitive training intervention can improve TTE performance by delaying mental fatigue. METHODS: Subjects were 28recreationally active individuals, with a mean±SD age of 22.1±2.6 years. They were randomly assigned to one of three intervention groups: a control group (CON) that was asked to exercise normally at home, and two groups that exercised in the laboratory either once (1X) or twice (2X) per week. Groups were designed to have nearly equal men and women. All subjects were asked to complete a graded exercise test (GXT) to exhaustion and a TTE before and after an 8-week intervention. All tests were completed on a cycle ergometer. The GXT consisted of cycling at a beginning workload of 70-85W and the workload increased every minute by 25-55W, depending on sex and training status. The TTE included a set workload corresponding to 75% VO2max. Training sessions included 1hr of cycling at 65% VO2max while continuously performing the AX-CPT task on a laptop computer. One-way ANOVAs were used to determine the effect of intervention group on change in TTE and VO2max values. RESULTS: CON had no change in VO2max (-0.8±4.5 ml·kg-1·min-1) and the experimental groups both had a small increase (1X: 2.8±5.4, 2X: 2.5±5.9 ml·kg-1·min-1); however, none of these were significant. There was not a difference between groups in VO2max change (p=0.313) or change in TTE (CON: -1.5±9.0, 1X: -1.8±15.8, 2X: 6.3±12.2 min; p=0.257). CONCLUSION: Although the 2X group saw an increase in TTE it was not significantly different from the other groups. This method has promise, however, as four individuals in the 2X group improved TTE compared to only two subjects in 1X, and one subject in CON. Some individuals may be non-responders to this type of intervention; this would explain the large variability. Alternatively, the lack of significant findings may suggest that the intervention should be longer or include more sessions each week.