You know you are getting a good workout when you start hallucinating. That actually happens during the world’s most extreme endurance races. The ultra-demanding events push mind and body to their limits and beyond, driving some competitors into the realm of madness. Some contestants report paranoia.

Think you are tough enough to handle that level of pressure? Get a feel for the obstacles presented by the toughest races on earth.

1. The Race Across America (RAAM) sounds like the title of a bland children’s adventure movie. But the official race website describes it as “the world’s toughest bicycle race”. Others call it “hell on wheels”.

The Race Across America dates back to 1982. Then, four brave-hearts raced from Santa Monica Pier in Los Angeles to the Empire State Building in New York City. Covered by national television, the race caused a sensation and captured the public imagination.

Now, the Race Across America starts at Oceanside Pier, California and ends in Annapolis, Maryland. The route covers 3,000 miles and involves
170,000 feet of climbing. En route, you cross 12 states, and whizz through 88 counties.

The Race Across America is 30 per cent longer than the Tour de France and, unlike its French rival, non-stop. That means minimal sleep.
What’s more, contestants must complete the distance in half the time allowed for the Tour. No wonder only half of all contestants finish. In fact, only 200 racers have ever made it to the Race Across America finish line. More people summit Everest than finish the race said to be the holy grail of “ultracycling”.

Contestants have died, been injured, even plunged into the realm of madness. Why risk losing your life and sanity?

The official answer echoes climber George Mallory’s comment about why he climbed Mount Everest: “Because it’s there.” The race’s stratospheric level of challenge fuels obsession.

2. The Spartathlon is a Greek extreme endurance race that traces the footsteps of Pheidippides: an ancient Athenian long distance runner armed with staggering stamina.

In 490 BC, before the battle of Marathon, the superman was sent from Athens to the ancient Greek city-state known as Sparta – the stomping ground of the ancient world’s toughest warriors, as the movie 300 records. His mission: to seek help in the war led by the Greeks against the Persians.

The original endurance athlete reached Sparta the day after leaving Athens, covering 250 kilometers. That is 155 miles: a distance few athletes would care to cycle in the 36-hour limit allotted to Spartathlon contestants.

You can see why the Spartathlon is reputed to be the world’s most grueling race. Liable to degenerate into zombies, contestants stumble and squelch across rutted tracks and mud caused by the rain that bedevils proceedings.  Contestants also have to slog up steep hillsides including rugged 1,200-meter (4,000-feet) Mount Parthenio in the dead of night. Devoid of a pathway, Mount Parthenio is swept by gales. Worse, temperatures plunge as low as 4 degrees Celsius.

By the time the last winding, hilly section that leads to Sparta arrives, even super-fit athletes start hallucinating. Maybe they see visions of Pheidippides on his epic mission. The Spartathlon’s heroic, historic side adds to the race’s allure. So too does the Mediterranean scenery. Think vineyards and olive groves rolling by in a giddy adrenaline blur.

3. Siberia, anyone? That is the location of the Baikal Ice Marathon.

Part of Russia, Siberia once hosted gulag prison camps where dissidents were sent to toil till they dropped in frozen heaps.
Siberia is seriously cold – so cold that the air singes your cheeks.

Your nostrils freeze together. The vapor in your breath instantly freezes and hits the ground with a tinkling wind chime sound called “star whisper” or “angel whisper.”

The sub-zero marathon that takes your breath away happens on the icy, treacherous surface of the world’s largest, oldest and deepest lake, Lake Baikal. Just to make Lake Baikal even more tricky, its surface is studded with “hummocks”: ice rubble hillocks. Between them and snowy stretches, polished pure ice zones exist, creating a skating rink effect.

Under the ice’s glinting surface, geothermic springs gurgle. Seismic activity unfolds. So, yes, that means the threat of holes. To finish the race across the lake you need nerves of steel, stellar stamina, phenomenal drive and agility.

Even if you possess those traits, you might still want to pray. Or, in step with Baikal Ice Marathon protocol, you might want to slug a vodka shot. Nostrovia! (Good health!).