Carson has been coached by Arch Jelley who is known for coaching New Zealand athlete John Walker to international success including a gold medal in the 1500 m event at the Olympic Games in Montreal in 1976. Although Jelly retired from coaching in 2000, five years later, he agreed to coach Carson, who subsequently represented New Zealand at the 2016 Summer Olympics in the 1500 metres. Jelley retired from coaching once more in 2018.