Exercise-Induced Cardiac Fatigue in Recreational Ultramarathon Runners at Moderate Altitude: Insights From Myocardial Deformation Analysis oleh Sebastián Wolff, José M. Picco, Leonel Díaz-González, Leonel Díaz-González, Pedro L. Valenzuela, Pedro L. Valenzuela, Emanuel Gonzalez-Dávila, Alejandro Santos-Lozano, Alejandro Santos-Lozano, Pablo Matile, David Wolff, Araceli Boraita, Alejandro Lucia, Alejandro Lucia