Answer:
Set clear goals.
Step-by-step explanation:
Xavier is exercising regularly but is doing random and unplanned exercises. This is because Xavier has not set clear goals for exercising. That is, he has no goal, so he cannot see the results of his training because he does not know what to evaluate and is not focusing on anything.
In order for exercise to have a positive effect on Xavier's body, he must set clear goals and exercise to lacerate those goals.