University of Physical Education 1 article published in JoVE Immunology and Infection Evaluation of Blood Lactate and Plasma Insulin During High-intensity Exercise by Antecubital Vein Catheterization Minas Nalbandian1, Zsolt Radak2, Masaki Takeda3 1Graduate School of medicine, Kyoto University, 2Research Institute of Sports Science, University of Physical Education, 3Graduate School of Sports and Health Science, Doshisha University Here we present a protocol to obtain several blood samples from the antecubital vein during high-intensity interval training. This protocol may be useful for the measurement of blood metabolites and endocrinal markers during exercise.