Easy runs are normal AND beneficial. You can be training for a 5K or marathon, you still need to incorporate easy runs. Think about it. You are doing challenging speed workouts and LONG runs. These types of runs fatigue your muscles. Just keep in mind when doing easy run to not worry about pace and focus on maintaining an easy effort.
So, what are easy runs?
It is exactly as it sounds! You run at an easy effort. They're not fartleks, or tempo runs or track workouts.. Not even the long runs. They're all the other miles. Easy runs make up a large part of your weekly mileage. They also make you stronger!
How often should I incorporate easy miles? Every run has some amount of easy running. when you have a track/speed workout, you will always being with a warm up and will most likely have a cool down. Those are easy miles! The number of easy runs you do during the week depends on your goals. Running super slow and relaxed for one to three days after tough workouts gets your blood flowing to muscles, which flushes away broken-down proteins and delivers new proteins to rebuild tissue.
How do I know if I’m running easy? I personally like to use my heart rate to know if I'm running easy enough. Keep in mind that everyone's heart rate zones are different and different things can affect your heart rate too. For example, I am a huge coffee drinker before runs. This can cause my heart rate to be higher. Or think of running in hot weather. Your heart rate will be higher than if you're running in really cold weather. A good rule of thumb is to think of easy runs as running at 60% effort and you should be able to hold a conversation too.