In mainland China, paramilitary policeman face an intense regimen. Here, the policemen take part in a training session in muddy water.
Paramilitary policemen jump during a training session in muddy water at a military base in Chuzhou, Anhui province, China, May 13, 2015. REUTERS/China Daily
Later in the training, the paramilitary police also have to crawl under fire obstacles ...
A paramilitary policeman crawls under fire obstacles during a drill at a military base in Chaohu, Anhui province May 5, 2014. REUTERS/China Daily
... and hone their hand-to-hand combat skills.
Paramilitary policemen react as they take part in a combat skills training session at a military base in Chaohu, Anhui province, China, June 25, 2015.
Training is sometimes aimed at pushing troops to their absolute limit: Here, paramilitary police in China train at holding their breaths underwater.
Paramilitary police snipers raise their heads from basins of water during a practice session of holding their breaths underwater, as part of a psychological training, at an annual drill in Nanjing, Jiangsu province, April 24, 2013. REUTERS/China Daily
Meanwhile, in far northern China, soldiers train in temperatures as cold as -22 degrees Fahrenheit.
Soldiers shout as they practise in temperatures of about minus 30 degrees centigrade (-22 F) in Heihe, Heilongjiang province, December 16, 2014. REUTERS/China Daily
In South Korea, members of the country's Special Warfare Forces also train in icy conditions.
A member of the South Korean Special Warfare Forces takes his position in frozen waters during a winter exercise in Pyeongchang January 8, 2015. REUTERS/Kim Hong-Ji
A Canadian soldier in Latvia takes part in ice-plunge training as part of NATO exercise Operation Atlantic Resolve.
A Canadian soldier, deployed in Latvia as part of NATO's Operation Atlantic Resolve, attends an ice plunge training during a joint military exercise in Adazi February 26, 2015. REUTERS/Ints Kalnins
During joint exercises, US and South Korean Marines train together in the South Korean mountains.
South Korean and U.S. Marines participate in a winter military drill in Pyeongchang, about 180 km (112 miles) east of Seoul February 7, 2013. North Korea has vowed to conduct more rocket and nuclear tests in response to a U.N. censure for its launch of a long-range missile. REUTERS/Lee Jae-Won
US Marines also take part in annual joint drills with their counterparts in Thailand, in opposite climatic extremes. During the jungle-survival exercises, Marines have the chance to drink cobra blood.
A U.S. Marine drinks the blood of a cobra during a jungle survival exercise with the Thai Navy as part of the "Cobra Gold 2014" joint military exercise, at a military base in Chanthaburi province February 13, 2014. REUTERS/Athit Perawongmetha
Here, a US soldier in the 10th Special Forces Group jumps off the ramp of a Chinook helicopter with his military working dog during an exercise.
A U.S. Army soldier with the 10th Special Forces Group and his military working dog jump off the ramp of a CH-47 Chinook helicopter from the 160th Special Operations Aviation Regiment during water training over the Gulf of Mexico as part of exercise Emerald Warrior 2011 in this U.S. military handout image from March 1, 2011. REUTERS/Manuel J. Martinez/U.S. Air Force/Handout
Over in Japan, members of the Ground Self-Defense Forces practice holding onto a rope dangling from a cargo helicopter.
Japanese Ground Self-Defense Force soldiers are carried by a rope from a CH-47 JA Cargo Helicopter during an annual training session near Mount Fuji at Higashifuji training field in Gotemba, west of Tokyo, August 20, 2013. REUTERS/Yuya Shino
In Taiwan, in order to pass the final stage of a nine-week Amphibious Training Program, a trainee crawls along a 150-foot path of jagged coral and rocks on his belly.
A trainee leopard crawls along a 50 metre-long path of jagged coral and rocks as part of the Taiwan Marine Corps frogmen "Road to Heaven" test in Zuoying, Kaohsiung January 19, 2011. The test is the final stage of a nine-week intensive Amphibious Training Program. REUTERS/Nicky Loh
In Belarus, servicemen must pass through an extensive and difficult obstacle course before becoming members of the elite "Red Berets."
A serviceman (R) from a special Interior Ministry unit takes part in a test near the village of Volovshchina, 25 km (16 miles) west of Minsk, October 19, 2011. Servicemen have to pass several tough tests before being awarded entry to the ministry's elite "Red Beret" unit, according to the ministry. REUTERS/Vasily Fedosenko
The Red Berets stage annual displays of skill where some troops head butt flaming concrete blocks.
A soldier of the Belarussian Ministry of Internal Affairs smashes blocks of concrete with his head at the Milex-2007 arms and military equipment exhibition in Minsk May 22, 2007. REUTERS/Vasily Fedosenko
Militaries around the world make use of endurance challenges. In Israel, soldiers from the Golani Brigade must complete a 43-mile march to finish advanced training.
An Israeli soldier from the Golani Brigade holds a comrade's hand as he helps him during a 70-kilometre (43-mile) march in northern Israel, marking the completion of their advanced training, at the end of which they receive their brown beret October 7, 2014. REUTERS/Baz Ratner
Enemy forces in the region have clearly taken note: In the Gaza Strip, Palestinian militants from the al-Aqsa Martyrs Brigades train in anti-Israel military drills.
Masked Palestinian militants from the al-Aqsa Martyrs Brigades, the armed wing of the Fatah movement, take part in an anti-Israel military drill in Rafah in the southern Gaza Strip March 25, 2015. REUTERS/Suhaib Salem
In Syria, members of the Kurdish YPG train on monkey bars and fire obstacles.
Fighters of the Kurdish People's Protection Units (YPG) are seen hanging behind a fire loop at a military training camp in Ras al-Ain February 13, 2015. Picture taken February 13, 2015. REUTERS/Rodi Said
Like the YPG, Iraq's Shia militias are one of the major ground forces fighting ISIS. Here, members of a militia demonstrate close-quarter combat skills at a graduation ceremony.
Shiite volunteers, who have joined the Iraqi army to fight against the predominantly Sunni militants from the radical Islamic State of Iraq and the Levant (ISIL), demonstrate their skills during a graduation ceremony after completing their field training in Najaf, June 27, 2014. REUTERS/Alaa Al-Marjani
Other Shia militias in Iraq require their members to take part in desert field-training exercises before graduation.
Shi'ite fighters, who have joined the Iraqi army to fight against militants of the Islamic State, take part in field training in the desert in Najaf, south of Baghdad, February 1, 2015. REUTERS/Alaa Al-Marjani
Discover More Like This
BACK TO SLIDE
The physical and psychological rigors of combat are intense, and militaries have the challenge preparing their soldiers for the worst of what they may face on the battlefield.
The world's militaries require their personnel to go through grueling training to equip them for life in the field, and to make sure that soldiers who might not have prior combat experience are still in a state of readiness.
Here are photos from around the world of some of the toughest training imaginable.