Objective
The role of the brain in endurance performance is frequently debated; surprisingly, few investigations have attempted to improve endurance performance by directly targeting brain activity. One promising but untested approach to modifying brain activity is electroencephalogram (EEG) neurofeedback. Consequently, our experiment is the first to examine an EEG neurofeedback intervention for whole-body endurance performance.

Method
We adopted a two-part experiment. The first consisted of a randomized parallel controlled design. Forty participants were allocated to three experimental groups; increase relative left cortical activity (NFL), increase relative right (NFR), and passive control (CON). They performed a depleting cognitive task, followed by either six 2-min blocks of EEG neurofeedback training (NFL or NFR) or time-matched videos of the neurofeedback display (CON). Next, they performed a time-to-exhaustion (TTE) test on a cycle-ergometer. We then tested participants of NFL and NFR groups in an additional experimental visit and administered the opposite neurofeedback training within a fully repeated-measures protocol.

Results
EEG neurofeedback modified brain activity as expected. As hypothesized, the NFL group cycled for over 30% longer than the other groups in the parallel controlled design, NFL: 1382 ± 252 s, NFR: 878 ± 167, CON: 963 ± 117 s. We replicated this result in the repeated-measures design where NFL: 1167 ± 831 s performed 11% longer than NFR: 1049 ± 638 s). There were no differences in pre-exercise fatigue, vigor or self-control; area under the curve group-differences for perceived effort were interpreted within a goal persistence framework.

Conclusion
The brief EEG neurofeedback intervention elicited greater relative left frontal cortical activity and enhanced endurance exercise performance.