How to Build Sustainable Running Mileage
It is common knowledge within the running world that a key way to improve speed is to improve your aerobic base. The only way to improve your aerobic base is to increase your overall mileage. However, many people often hit walls when building up their mileage and it can be tricky to get the balance right.
Increasing your weekly mileage too quickly can rapidly lead to burnout and injury. Managing your intensity poorly can rapidly lead to burnout and injury. Getting both wrong will result in you not getting very far at all! It’s starting to sound like improving your aerobic base is a path filled with traps and pitfalls, but do not fear! There are, thankfully, some fairly simple ways to approach your mileage increase that will ease this path and pave the way to success.
Speed
One of the biggest issues most people encounter when building their mileage is simply that they run too quickly.
Efficiently building your aerobic base generally requires you to be running in what most people will refer to as ‘zone 2’, which is a level of effort where you should be breathing comfortably and able to talk in full sentences. People commonly use heart rate to measure their effort zones and depending on your age, your running heart rate zones will vary.
How to work out your heart rate zones?
These days there are countless heart rate zone calculators available to estimate your heart rate zones. The downside of these calculators, and indeed the downside of the old fashioned way of working it out (doing the sums yourself), is that it requires your maximum heart rate.
Most of us won’t know exactly what our maximum heart rate is. The only way of getting a completely accurate figure for your Max HR is by having tests done in a sports performance lab, which is something we all obviously have available just around the corner. We can gain estimates of our max HR by doing fitness tests, such as the one found here or by doing some more good old fashioned maths. 220 minus your age will give you an estimate of you max HR.
In reality, for most of us an estimate of max heart rate is perfectly sufficient and using one of these methods to estimate your max HR will allow you to estimate your heart rate zones with only a handful of beats per minute error.
The other issue to be aware of is that the wrist heart rate monitor available in most running watches will not be 100% accurate, so take this into account when using a running watch to track your heart rate during runs. Other options are available that may provide more accurate monitoring. Bicep monitors use the same system as wrist monitoring, but the positioning makes them more accurate. Chest straps use a slightly different system and are consequently the most accurate piece of equipment to use for tracking heart rate during exercise.
Don’t want to use heart rate?
You don’t necessarily have to use heart rate. It can be a faff thinking about all the numbers while you’re running and sometimes wearing an extra strap somewhere on your body can be uncomfortable. Many runners are happy training on feel and if you’re running at a pace where breathing is easy and you can hold a conversation (or sing for the more extroverted amongst us) then you’re moving slow enough to build your aerobic base.
Speed work?
Speed work is important for getting quicker, but how much do you need to do and how quickly do you need to go?
The 80/20 rule is now well established as a good balance between aerobic mileage and speed work. This means that roughly 80% of your weekly mileage should be at an effort of zone 2 or lower and a maximum of 20% should be performed above this effort level.
This rule ensures the consistent development of an aerobic base and enough speed work to stimulate top end speed but without overstretching the nervous system or risking over fatiguing the muscles. Muscle recovery is essential for maintaining a regular running schedule as well as growth and development.
For beginners, speed work isn’t necessary. It’s best to build up your aerobic base over a few months before introducing any significant speed work. If you want to make things a little more interesting then you can play around with a Fartlek workout (a Swedish work loosely translating as ‘speed play’) where you pick up your pace during a run for often random intervals. This can add a little spice without risking overstretching yourself.
For intermediate runners, tempo runs and interval sessions will likely be a regular feature. To start with you may want to just have one structured speed session in your weekly training schedule, but over time you may wish to increase this to two. Hill workouts are a great tool for runners of all levels. As well as the strength benefits from hill workouts, they also allow you to push for higher effort while reducing the impact on your joints and ligaments. This is great for reducing injury risk.
Advanced athletes may find themselves doing as many as four workouts a week, potentially two on the same day, but this is more likely to occur at the sub elite and elite levels, which thankfully most of us won’t need to worry about!
The Long Run
Another area where over fatigue can occur and injury risk can increase is on the long run. Most runners will have a long run in their weekly schedule as one longer, slower effort each week is key for aerobic development. However, one trap that people can fall into is making their long run, too long.
A long run can be too long? Yep! If too much of your weekly mileage is concentrated into your long run, it increases the risk of injury and piles on the muscle fatigue. For the majority of people, ensuring that your long run is not more than 30% of your overall weekly mileage is the most sustainable approach.
While the long run is important, distributing your mileage more evenly across the week allows for more consistent stimulus, avoiding your body having to take a significantly increased load of stimulus on one day compared to the other days of the week.
It’s worth noting that you can get away with pushing your long run mileage up compared to the rest of your week if you’re a more experienced runner and are short on time, but it’s not recommended as a long term training method.
Weekly Mileage Increase?
For most people, it is advisable to never increase your weekly mileage by more than 10% from the previous week. More experienced runners may be able to play around with this a little bit but big jumps in mileage should always be avoided.
Some runners may respond well to jumping their mileage up by 20% in one week, but then holding that same mileage for three weeks before increasing it again. However, this method should only really be tried by more experienced runners.
Final Takeaways
The way you approach a mileage build can vary depending on the person. Some people benefit from running for shorter distances more often and keeping their long runs on the shorter side, some people get on better with mileage condensed into fewer days and full days off running completely.
If you’re a newer runner then it’s best to keep to a very gradual increase for a good few months to let your body adjust to the increased workload. Patience is the key!
Hopefully this article has been of use to you! Check back each month for a new article on running. We cover all kinds of advice, including strength training for runners as well has how to approach training.
So Remember:
Run 80% of your mileage at an easy pace
Introduce speed work (intervals and tempos) gradually
Keep your long run to a max of 30% of your weekly mileage
Train safe!
