I'm a big fan of P90X. The program works for 2 main reasons, which I think can be applied to other areas of our lives.
1. Consistency - The 90 represents days. If you consistently exercise for 90 days in a row you are bound to see some results.
This can be applied in all areas of life. If you want to increase your knowledge of something, consistently study it for 90 days. If you want to strengthen your spiritual life, pray consistently for 90 days. If you want to improve your relationship with someone, serve and pursue them for 90 days. Consistently doing anything on a daily basis will create positive habits to get the results you desire.
2. Variety - The P90X program works because it is designed around muscle confusion. Basically, it works out the same muscle in different ways. So instead of simply doing bench press to build your chest you would do a variety of exercises including multiple types of push-ups, dumb-bell presses, yoga holds, Kenpo karate moves, and other chest exercises that you've never heard of before.
If we keep doing the same stuff we will keep getting the same results. When you read, make it a point to read a variety of books, blogs, and magazines. Switching between fiction, christian, business, occupational, leadership, health, and other topics keeps your mind sharp as you think in different ways. When you pray, do so in a variety of ways including silently, aloud, written, alone, with someone, while driving, showering, running, etc... When spending time with someone, grab dinner, an early breakfast, go on a walk, exercise, attend a concert or museum, create something, go on a road trip, or just be adventurous. You are still spending time with the same person, but by doing so in a variety of ways you are strengthening the relationship.
Learn from the success of P90X. What do you need to be more consistent with? How can you add variety to areas of your life?