There are 16 activities in total broken up into four groups - 12 activities are optional, four are compulsory. You need to complete at least 10 activities over the event duration to be an official Tough Mudder Challenges finisher.
Group 1: Complete all 4 of these compulsory activities.
Group 2: Complete 2 of 4 activities. You can pick which 2 activities you’re completing.
Group 3: Complete 2 of 4 activities. You can pick which 2 activities you’re completing.
Group 4: Complete 2 of 4 activities. You can pick which 2 activities you’re completing.