As the weather turns nice each spring, be careful about transitioning your running routine from winter treadmill to summer pavement. 

If you are returning from an injury or preparing for a race, I suggest following this simple guideline. First build your volume, which can be done during the winter months on a treadmill and maybe a few outside runs. Once you have attained your volume goal, add speed. The final step is to add terrain. Following this general guideline will help reduce injury as well.  

Once you get outside, it is important to control your terrain. You may live in a hilly neighborhood. Since the hills are there, you should adjust the other two variables. I typically begin by reducing volume and maintaining the same pace. There is not a magic formula that can tell you exactly how much you should change. At times, you will need to change based on how you feel physically and mentally.  

An example, a 45-year-old male runner averaging 20 miles per week on the treadmill over the last several months has been doing 80% of those miles at no more than a 1% grade. His pace is generally around a 9-minute mile. He now wants to go out and run all of his miles in his hilly neighborhood.  

Start by changing the volume. In this example, the runner decides to decrease from 20 miles per week to 16 miles per week, roughly, a 20% reduction. During the winter, the runner generally achieves his 20 miles week by running three days per week. Now, with this change in terrain, he has decided to increase to running four days per week instead of three. By increasing the number of running days, the runner will be able to spread out the increased load on his body. Remember, in this example, the increase in load is the terrain.  

Now that we have a starting point, how does this runner progress back to his 20 mile a week goal? I would begin by progressing the total mileage per week by around 10%.  The runner can always progress more but I would not suggest increasing his mileage more than 30% per week.  

There are many options and ways to increase volume, hills and terrain. There is no one right answer because every person's running history and health are different.