There are 3 components to optimum physical fitness.
1. Muscular Strength
2. Cardio endurance
This means (at least) 30 minutes of cardio on most days of the week, strength training at least twice a week and flexibility training.
I am often guilty of focusing on two out of the three categories, running long distances and getting in a couple of strength sessions a week, but constantly falling behind on my flexibility training.
Think about how much time you devote to each component in your week, and then make it your goal next week to devote more attention to the one or two lacking your attention.
Often times it is the exercises we hate that are the most necessary for us to practice.