Challenge Northumberland, the organisers of the Mad March Mare, to take place at Hexham Racecourse on March 4, announced that all 1,000 places on the 10km obstacle run have been bagged.
Now in its third year, the event has rapidly grown in popularity and selling out with four weeks to go is strong proof of this.
It is seen as a good warm-up event ahead of larger mud runs held across the country.
In a further piece of good news for the event, former Olympic and Commonwealth Games gymnast Craig Heap has been confirmed as the official starter for the runs on the day.
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