Tough Mudder , which was started by two Harvard Business School graduates in 2010 , is an endurance event series . On Sunday thousands flocked to San Bernardino in California to take on the challenge . The next Tough Mudder events are set to take place on May 2 and 29 in London , Texas and Atlanta . The average age of contributors is 3 with 70 per cent male and 290 per cent female .
Tough Mudder , which was started by two Harvard Business School graduates in 2010 , is an endurance event series . On Sunday thousands flocked to San Bernardino in California to take on the challenge . The next Tough Mudder events are set to take place on May 2 and 3 in London , Texas and Atlanta . The average age of contributors is 29 with 70 per cent male and 30 per cent female .