The current record is 833km, but Timmis has passed the 375km mark in less than 44 hours.
She began her attempt on Sunday and runs from 5.10am until 10pm each day at the Ngā Puna Wai Sports Hub.
Timmis has been living on the treadmill, doing everything from eating and drinking to chatting with her support crew.
But she takes a 30-minute break every four hours to eat solid food and change her shoes and socks and the dressings on her feet.
The long-distance athlete and artist said the past four days have been a rollercoaster ride as she struggled with stomach cramps and vomiting.
“There’s been ups and downs. The first day was great, the second day was terrible, the third day was terrible.”
“There’s four people in the support crew - two in the morning, two in the evening, and they’re just going above and beyond to do everything for me.
“A record like this doesn’t happen without an impeccable crew.”
Timmis is raising funds for mental health and addiction recovery charity The Speed Freaks.
Together they had raised more than $5800 and covered over 856km by Thursday morning.
Timmis holds the world record for running the length of New Zealand (female) in 20 days, 17 hours, 15 minutes and 57 seconds.
She also holds the record for the longest journey by elliptical cycle in a single country (7951km). And she accidentally smashed the 48-hour treadmill world record last year (340.36km).
Timmis will finish her run on Sunday evening and hopes to celebrate with a sleep and massage.
- To donate and support Timmis on her #7DayTreadyRecord challenge, visit treadyworldrecord.raiselysite.com.
By Isabella Adams
