What is the point of easy miles?
Why do I need to run easy?
If a TWB runner sees an easy run scheduled on their training plan they know that this broadly means a day of varying length at a low intensity- it’s a day to where a conversation with other during your run should be possible. These days are not meant to be close to marathon pace and run at a pace that feels about as easy as running can. So why are these days scheduled then, what is the point in running considerably slower than you might be racing at a pace that feels well, easy?
Any training schedule worth its weight in salt will have easy runs in the schedule. I get asked all the time when prescribing easy days what is the point of running such a slower pace than what they’re trying to run for even a marathon? It can be easy to wonder what the point of it is or even find the motivation to get out the door- especially when you’re running low on sleep or on time.
I would argue that that easy days are the most important part of training and here is why:
Recovery
Hard workouts, long runs, and races are the days that we challenge ourselves. In order to get better we have to challenge our body which breaks us down. Easy runs are the days in-between that build us back up, If you never take an easy day you’ll never allow your body to super-compensate to become stronger and faster than it was before. Technically speaking hard workouts don’t make us better- how we recover from those efforts is actually what makes us better and if we never give our body proper time to recover we won’t see the improvements we hope for.
Slow easy running helps push oxygen rich blood through our body which provides the necessary materials to rebuild the micro-tears that occurred doing a hard workout. Many people see recovery as the absence of training but that’s not true recovery is a PART of training. An easy formula to remember this by is this:
Stress(workouts) + Rest(recovery days)=growth
Think about it in a survival standpoint from our ancestors; after a big hunt did cavemen lay around on the couch the following day to recover? No, they had others tasks to complete and our body has evolutionary adapted to being able to recover while on the move- albeit at a much lower intensity
Easy runs, if run correctly are meant to be aerobic in nature. Not to get into the nitty gritty details but like discussed earlier you should be able to have a conversation while running during an easy run. By running aerobically that means the body is able to process the waste product in a timely fashion that muscles produce during your exercise. Since there is no build-up of this waste product there is much less damage done than if you were to run a distance as hard as you could.
And all of this leads into our second point.
2. Building Aerobic Strength
If run correctly an easy run shouldn’t be necessarily difficult but that doesn’t mean you’re not getting any benefit from it! Like we mentioned in the previous section easy running is aerobic running where a bulk of our mileage should come because the biggest percentage of energy contribution for any race that we are likely to run (even down to the mile) comes from the aerobic energy system. The graph below highlights my point.
Even the 5K which at times can feel like an all out sprint to some marathoners is still 84% aerobic! That’s an incredibly high number and each and every time we go out there to run easy we are training that energy system that will help carry us to the finish line in any distance race. There is no better way to become a better miler to marathoner than to run easy.
Still not sold on the importance of an easy run? No worries there are still tons of other benefits that we we’ll give you a surface level view to explain what is happening and most importantly- why it matters to you.
3.Mitochondria density
Remember that phrase from high school biology? “The mitochondria is the powerhouse of the cell”. We had this phrase drilled into our heads and your biology teachers were right. Think of mitochondria like an engine, the more engines you have the more power you will be able to produce over a given time.
Aerobic running increases the density of this powerhouses in our cells by the amount of time we’re able to run at this intensity. Simply put the more powerhouses you build within each cell the more energy you will be able to spend on your next race.
4.Capillary Development
Our bodies are great at adapting to become more efficient at what we do. Capillaries are our smallest blood vessels, this is where the transfer happens between our blood and our muscles.
By running for extended periods of time our body will create a larger network of capillaries and networks to provide a more efficient exchange as our blood brings energy and oxygen to the working muscles. The more open points of these transfers to happen the more efficient our body can be running at any pace!
This capillary development never fully disappear even years after stopping to run. That’s why the term “old man strength” can come into play. Former runners who are getting back into running can return much faster than people who are beginning for the first time.
5.Muscle, bone, and ligament adaptation
Low Intensity exercise is a great bridge that can help keep us healthy while running fast. At a low intensity exercise the muscles are taken through the range of motion for running with enough stress that allows our body to super compensate and become stronger. Someone who is only running hard and not at all in-between is more likely to get injured because the structure of our body isn’t being stressed enough to see those adaptations necessary for pain-free running! By running our bone density becomes higher, our muscle fibers become stiffer and our ligaments get stronger all of these changes will keep us running pain free when hard workouts are lined up.
The importance of easy runs cannot be overstated. They are a crucial piece to any good training program. While the workouts may be the fun ones to run because of the fast splits- the mileage we do in-between those runs is just as important. To become a more efficient, energy filled, injury free, stronger runner. Easy runs are your best bet!