When it comes to training, the redundancy implied from a "routine" doesn't always need to be applied. If you run the same 3 mile loop every day, your body will eventually become accustomed to it. The initial results you received from your runs will eventually taper out and plateau. Fortunately, there are ways to fix this. If you want to direct your workouts to receive constant results, varying your activity is vital.
This puts us in a predicament. What do to do now? Well, one option is to continue doing the same thing we were doing and not receive the physical benefits that we were once striving for. The other option is to try something new. When we change our workouts and "shock" the body, we respond to that activity more drastically. That "shock" response is expressed by what ever that activity demands; increase in strength, more endurance, higher VO2 max, etc. The best way to think about this physical phenomena is to view this reaction as a defense mechanism. I know, it sounds a little crazy, but it makes sense. Since our genetic code has not changed in thousands and thousands of years,let's think about what happened when we were trying to survive in the wild. If a human wasn't fast or agile enough to catch a dear for food, or maybe even pick up something up that was really heavy (perhaps rocks or branches for shelter) then that would result in compromising chances for survival. As a defense mechanism, the body naturally increases speed, agility or strength just in order to stay alive (whether it be catching that dear or picking up that rock). This theory still applies today.
Since we don't catch our own food anymore or build shelter, we can see our bodies physically react to our workouts. If we sprint as fast as we can or pick up a weight that gets really heavy,we are naturally going to get faster or put on more muscle in order to be prepared for the next time we are in that situation (same thing like trying to catch an animal or pick up heavy rocks for shelter).
However, if we don't lift weights that are heavy for us or don't run to the point of physical fatigue, we aren't going to reach those results....just a flat plateau. Since it is now officially summer (and the weather is now permitting), we have so many more options to vary our workouts. If you are just a runner, try some of outdoor pools for swimming. If you have just been lifting weights, go for a run in the park. Try running the stairs if you have just been doing even paced miles. You can even hop on a bike and put some miles on your belt. If you really enjoy variation, try multi-sport events such as a triathlon. Priority Fitness' trainer Chris will be doing his first NYC Triathlon this July 26th, Go Chris!! Varying your activity can also keep our minds from "plateauing". It's extremely important to keep our heads fresh and feel excited for all the different types of things out there.