A participant dives into a mud pool during the Mud Day athletic event at El Goloso Military base on the outskirts of Madrid, Spain, Saturday, June 11, 2016. Thousands of athletes got covered in mud as they celebrated International Mud Day running a 13-kilometer obstacle course on a sunny Saturday with heatwave-like temperatures up to a 29 degrees Celcius (around 84 degrees Fahrenheit). (Photo by Paul White/AP Photo)





A participant dives into the mud pool during the Mud Day athletic event at El Goloso Military base on the outskirts of Madrid, Spain, Saturday, June 11, 2016. (Photo by Paul White/AP Photo)





A participant swims to cross a mud pool during the Mud Day athletic event at El Goloso Military base on the outskirts of Madrid, Spain, Saturday, June 11, 2016. (Photo by Paul White/AP Photo)





Participants run in the mud during the Mud Day athletic event at El Goloso Military base on the outskirts of Madrid, Spain, Saturday, June 11, 2016. (Photo by Paul White/AP Photo)





Participants pose for a photograph during the Mud Day athletic event at El Goloso Military base on the outskirts of Madrid, Spain, Saturday, June 11, 2016. (Photo by Paul White/AP Photo)





Participant start the Mud Day athletic event at El Goloso Military base on the outskirts of Madrid, Spain, Saturday, June 11, 2016. (Photo by Paul White/AP Photo)





A participant runs in the mud during the Mud Day athletic event at El Goloso Military base on the outskirts of Madrid, Spain, Saturday, June 11, 2016. (Photo by Paul White/AP Photo)





Participants compete in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





A participant competes in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





A participant competes in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





Participants compete in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





Participants compete in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





Participants compete in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





Participants compete in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





Participants compete in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





A participant competes in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





A participant competes in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





A participant competes in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





A participant crosses the electric shock area as he competes in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





A participant is helped by an Spanish soldier at the electric shock area in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





A participant competes in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





Participants cross the electric shock area as they compete in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





A participant competes in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





Participants compete in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. (Photo by Juan Medina/Reuters)





A participant swims in the mud pool during the Mud Day athletic event at El Goloso Military base on the outskirts of Madrid, Spain, Saturday, June 11, 2016. (Photo by Paul White/AP Photo)





Participants swim in a mud pool during the Mud Day athletic event at El Goloso Military base on the outskirts of Madrid, Spain, Saturday, June 11, 2016. (Photo by Paul White/AP Photo)





A participant stops to cool off during the Mud Day athletic event at El Goloso Military base on the outskirts of Madrid, Spain, Saturday, June 11, 2016. (Photo by Paul White/AP Photo)





A participant slides down a mud hill during the Mud Day athletic event at El Goloso Military base on the outskirts of Madrid, Spain, Saturday, June 11, 2016. (Photo by Paul White/AP Photo)





A participant with a slice of melon in his mouth carries two beers after crossing the finish line at the Mud Day athletic event at El Goloso Military base on the outskirts of Madrid, Spain, Saturday, June 11, 2016. (Photo by Paul White/AP Photo)