This is a time to just enjoy running easily and having fun. Without this important break, you may burn out or get injured as you never give your body adequate time to fully adapt to, and recover from the last few months or years of training. Most elite runners actually take more breaks from running then recreational runners, so don't be afraid to take a break every so often and just limit your body to low intensity stress. Training at the same intensity, completing the same workouts and weekly mileage all year round will only take you so far, incorporating some well structured periodization, which includes time dedicated for base training, will be more beneficial in the long term at achieving your goal of improving running performance. Easy running will constitute the majority of your base training.
Easy runs correspond to a comfortable, conversational pace.
The appropriate pace for easy runs is up to 70 percent of your VO2 max, which corresponds to 75 percent of your vVO2 max or maximum heart rate. This is as fast you will need to go to get the benefits you want at the cellular level and in the heart muscle. On the lower end, you should try to run at a pace corresponding to 50 percent of your vVO2 max or maximum heart rate. The benefits of easy running are more a function of the time spent running rather then the intensity of the run. During base training, it is also a good idea to slowly begin incorporating your weekly long runs up to the maximum level you would like to reach during the year when you are completing more intense training.