I had my best overall session last night training static holds for the Iron Cross! Here is a video of my best level 4 hold that night. Level 3 has also now become very easy and i can hold it without pulling the sex face.
From here, I aim to build up the amount of time holding level 4 so that my body is completely prepared for the inevitable strain of moving up to level 5. Thirty second holds seems like a suitable target as it would ensure that I'm completely adapted to the current load before increasing it further.
The overall session went as follows:
Level 1: 15 seconds
Level 2: 20/26 seconds
Level 3: 15 seconds
Level 4: 7/6/4 seconds
