Dr. Stephen Seiler, a leading physiologist from the University of Agder renowned for his research on polarized training, discusses an innovative project focusing on breathing frequency as a training metric. He explores how this approach may better align with perceived exertion than heart rate, offering deeper insights into athletes' performance. The conversation also covers the complex mechanics of breathing, the potential of wearable technology in measuring exertion, and the importance of personalized respiratory training for optimizing athletic performance.