"It's disappointing, it's going to be a bit hard heading home to Christchurch. They are places in Christchurch I know well, I grew up in Christchurch, drove past those areas weekly and spent a lot of time growing up at school in that area. It's pretty close to home."
He said it was important to carry on with normal life as much as possible.
"I think we have to go about our day-to-day life still, obviously mourn for a bit, but I guess put it to the back of your mind as quick as possible, as if it hasn't happened, as hard as that is."
Yesterday,Cooper took to Facebook to express his feelings on what he described as a "hateful attack".
National Champs tomorrow in Rotorua but I find my mind more focused on the terrorist attacks back home in Christchurch....
Posted by Anton Cooper on Thursday, 14 March 2019
"National Champs tomorrow in Rotorua but I find my mind more focused on the terrorist attacks back home in Christchurch. No matter your faith or religion you should feel safe in New Zealand and it feels that New Zealand's innocence has been ripped away in just one day and one hateful attack. Kia Kaha Christchurch."
On the course, in the Whakarewarewa Forest, Cooper was pushed all the way by fellow Cantabrian Ben Oliver, but was always in control as he finished his five laps in 1h 20m 30s, 20 seconds ahead of Oliver. Rotorua's Sam Shaw was third in 1h 27m 20s.
Meanwhile, Oceania and New Zealand champion Samara Sheppard, of Wellington, successfully defended her national title, finishing her four laps in 1h 18m 29s, ahead of Wellington's Kate McIlroy (1h 22m 47s).