The event, which also includes racing in a middle-distance category and a relay, is doubling as round one of the World Cup season.

In each race the riders must navigate from start to finish with just a map and a compass, ensuring they pass a number of marked control points along the way. 

Vojtech Ludvik won a gruelling 40.5 kilometres men's race by almost two minutes in 2 hours 7min 26sec.

Luca Dallavalle of Italy clinched second place in 2:09:20 by just one second in front of Russia's Ruslan Gritsan.

Martina Tichovska then completed the Czech double in a 30.2km women's race.

She crossed the line in 1:58:27 to thrash the rest of the field.

Olga Shipilova of Russia finished a distant second in 2:06:10.

Third place went to Antonia Haga of Finland in 2:07:32.

Action is due to continue tomorrow.