Astle was born in Feilding. He is the father of Todd Astle. He played two first-class matches for the Central Districts in the 1978–79 season. He also played for Manawatu in the Hawke Cup.
Astle was a long-serving and influential staff member, cricket coach and Deputy Rector of Palmerston North Boys' High School, where he taught for 24 years.[1] After that, he served as national development manager for New Zealand Cricket in Christchurch for more than 10 years.[2] He then worked for Spark as a community sport manager.[1] While in Christchurch he served as President of the Christchurch Metro Cricket Association, and in recognition of his service he received a Lifetime Service Award at the 2019 Sport Canterbury Awards.[3]
He was awarded a master's degree in 1975 and a PhD from Massey University in 2015, writing his doctoral thesis on the importance of the grassroots level of cricket.[4][5][1] He is the co-author of Sport Development in Action: Plan, Programme and Practice (2018), a textbook on the development of sport in communities and schools.[6] With fellow Central Districts and Manawatū player Murray Brown, Astle wrote 125 Not Out, the official history of the Manawatū Cricket Association, in 2021.[7]