Exercise can cause/lead to Injury. Exercise is a different concept from Fun. Writing can be used for Fun. 
Very is related to Oil. Oil is related to High. High is a synonym of Proud. 
Injury <--Causes-- Exercise <--DistinctFrom--> Fun <--UsedFor-- Writing 
Very <--RelatedTo--> Oil <--RelatedTo--> High <--Synonym--> Proud 