Hannah Cockroft will discover whether she has the necessary endurance and strength for more IPC World Championships success in Doha on Wednesday.
Halifax’s “Hurricane Hannah” steps up to the 800 metres, having swept away the opposition at shorter distances.
And she has described the longer test as “worrying” and “scary” as she builds towards next year’s Rio Paralympics.
At least Hannah, 23, is in good form.
She was one of four Great Britain gold medal winners on the opening day of the championships.
The European, world and Paralympic champion had come to Doha after losing to 14-year-old rival Kare Adenagen in London last month.
However, she claimed her third successive T34 100m world title in a time of 17.73 seconds - 0.82 ahead of American Alexa Halko with Adenagen fourth.