I think you meant an alternative life style!Lifetime = 毕生; Everyone has only one lifetime.How can you have an alternative lifetime.每个人只有一个毕生.你怎么能有一个另类的毕生.No matter how 'alternative you can make it,it is still your only one lifetime.
Unless,the missing part of this sentence laid out another lifetime as an comparison.
an alternative life style = 另类生活方式.