Biathle is a sub-sport of Modern Pentathlon invented to create opportunities to train Running and Swimming parts of Pentathlon in real race conditions.
It can also be seen as a sport in its own right.
Biathle is an event that involves the following sequence Run-Swim-Run. It is a world class sport but not an Olympic one. The legs are raced with continuous transitions like triathlon. The race length is usually 200m swim and 3200m run.
UIPM Biathle events, like UIPM Triathle events, can be organized at all kind of sceneries: ocean, sea, lake or river and can be run on all surfaces: sand, asphalt, concrete, pavement, etc …
Get all the technical data here.