Timed unsupported standing on a balance mat with feet together, eyes closed and head turns

Stand on a balance pad close to a sturdy object to hold onto for stability if needed.
Your feet should be touching.
Get your balance and close your eyes, keeping the support nearby if you need it.
Slowly turn your head from side to side.
You could use a stopwatch to time yourself, aiming to increase the length of time with every repetition.