Research has consistently shown that around 70% of running injuries are caused by overuse and training errors such as increasing mileage too quickly, or making sudden changes to your routine. The good news? Many of these are preventable with the right approach, so we're here to help with some mileage tips.
Whether you’re brand new to running, experienced, or returning from injury, increasing your mileage needs to be done safely. Your Runna plan meets you exactly where you are, with progression based on your current baseline so you can build fitness sustainably and with confidence.
Common Mileage Mistakes
Increasing mileage without including strength training
When weekly mileage increases, so do the demands placed on your muscles, tendons, and joints. Without strength training to build resilience and improve load tolerance, your body will struggle to absorb that extra stress. Even if strength training is something you view as the boring part of your running plan, your future miles will thank you, especially if it means preventing an overuse injury. Just one session per week can make a big difference.
Including some single-leg work is also key and will significantly improve your running efficiency and build greater resilience.
Add strength training to your plan by heading to the ‘Manage Plan’ tab. Simply tell us which days you’d like to include sessions and how long you'd like them to be. You don’t need access to a gym – we personalize your sessions based on the equipment you have available.
Using past performances or fitness from other sports to judge your ability
If you're returning to running after a break, or you are used to regularly playing other sports, it’s easy to think you should be able to handle a high mileage. However, your body only adapts to what you’re consistently doing now, not what you did before. Jumping back to old mileage too quickly increases injury risk.
If you have a background in other sports, you may already have strong aerobic base fitness – but it’s important not to underestimate the repetitive impact of running on your muscles, tendons, and bones. Every stride requires your body to absorb and produce force, so even with good cardiovascular fitness, you may not yet be conditioned for higher mileage. Keep your progression steady and you’ll build fitness quickly while keeping it sustainable.
Ex-professional cyclist, Manon Lloyd, explains the importance of keeping progress steady when transitioning to running from different sports in this episode of the Runna podcast.
Ignoring early warning signs (fatigue, soreness)
Minor aches and pains, lingering soreness, or unusual fatigue are often early signs that your training load is climbing too quickly. Pushing through these signals whilst still continuing to add mileage can turn manageable fatigue into a more serious injury. Listening and adjusting early is far more effective than being forced to stop later.
Excitement after a good race or fitness milestone
Strong races or sessions can boost your motivation and confidence. It’s tempting to capitalize on that momentum by immediately adding more miles, but fitness gains don’t mean your tissues are instantly ready for a big jump in load.
Your cardiovascular system often adapts faster than your muscles, tendons, and bones. Within a few weeks of consistent training, you may notice your pace getting faster or efforts feeling easier because your body is delivering oxygen more efficiently. However, your muscles, tendons, ligaments, and bones adapt more slowly. These tissues need more time to strengthen and rebuild in response to impact and load.
Make sure you're including strength training and stick to the 10% rule...
Tips for Increasing Mileage Properly
The 10% Mileage Increase Rule
Increasing your weekly mileage by only 10% week on week keeps progress controlled. For example, if you ran 20 miles last week, you’d aim for no more than 22 miles the following week. The idea is to keep progression gradual and reduce the risk of overload injuries.
When you build your plan, Runna asks for your current weekly mileage and longest regular run. This ensures your training starts from where you actually are so your mileage progresses optimally for you.
The best approach considers this rule, whilst also considering how your training weeks are feeling based on overall training load and perceived effort. This means considering how hard your runs are feeling and how well you’re recovering before adding extra miles.
Don't Increase Intensity and Volume at the Same Time
Increasing both volume (total mileage) and intensity (more speed, intervals, hills, tempo work) simultaneously places a much greater load on the body. If you’re aiming to increase both, build them in phases.
First, gradually increase your mileage while keeping easy runs truly easy. Once that feels stable and recovery is consistent, hold your mileage steady and try swapping one easy run for a tempo or interval session. From there, make small adjustments based on how your body responds.
This staggered approach allows you to adapt safely – and if something feels off, you’ll know clearly whether it’s the mileage or the intensity, since you haven’t increased both at the same time.
Make Sure Your Easy Miles Are Actually Easy
When increasing mileage, easy runs are key in allowing you to add volume while still recovering and building aerobic fitness. If you run them too hard, you blur the line between easy and quality work, making it harder to absorb the extra mileage and increasing your risk of fatigue or injury.
Protect your easy miles to ensure your harder sessions stay effective and your overall progression remains balanced and sustainable.
Consider Cross-Training
Cross-training is definitely worth considering before adding more miles, especially if you’re new to running or have a history of injury. Activities like cycling, swimming, or using the elliptical will boost cardiovascular fitness without the same repetitive impact that extra miles bring.
This allows you to increase your overall aerobic load while giving your muscles, tendons, and bones more time to adapt to running-specific stress, helping you build fitness in a safer way.
Monitor Your Progress With Runna's Mileage Insights
If you’re adding extra miles, it’s important to monitor how your training load is progressing. Small increases can add up quickly and tracking trends helps you spot changes in how your body feels.
Want to better understand how your mileage is building over time? Our Mileage Insights feature tracks patterns in your training load and suggests adjustments to your mileage when needed – helping you build more consistently and reduce the risk of overdoing it.