The ten minutes before Speaking

You cannot warm up inside the section

Speaking is eleven questions with no planning phase anywhere. The first Listen and Repeat item arrives with an eight-second window, and whatever state your mouth is in when it arrives is the state it is answered in.

That makes Speaking the one section where what you do immediately beforehand actually changes the score. For Reading it barely matters. Here, the difference between a cold first answer and a warm one is two or three items — out of eleven.

What actually helps

• Speak out loud, at conversational volume, for two or three minutes. Anything — describe the room. The point is that your first spoken English of the day should not be question one.
• Say a few long sentences with full endings. Plurals, past tenses, articles. Those are what the repeat task measures and they are the first thing to go when cold.
• Drink water. A dry mouth costs you clarity on the eight-second items where there is no time to recover.
• Check your microphone level on something you do not care about, not on question one.

The real fix is earlier than ten minutes

A warm-up moves a cold start to a warm one. It does not build the thing being tested — whether you can hold a sentence intact under an eight-second clock, or shape an answer inside forty-five seconds without planning it.

Both of those are reflexes, and reflexes come from having done the thing under its real conditions often enough that the clock stops being the obstacle.