Running | Training & Injury Prevention
How Much Further Should Your Long Run Go?
New research suggests that sudden increases in running distance may matter more than weekly mileage when it comes to injury risk. So how much is too much, and what should runners do with that information?
Nicholas Barbousas / Rolfing Melbourne, Clifton Hill
If you're preparing for a half marathon or marathon, or simply building your running distance, the long run is an important part of your training.
Increasing distance isn't always straightforward. You might be managing your usual weekly runs comfortably, then develop an unfamiliar ache after pushing your Sunday run a little further. Sometimes it settles within a day or two. Other times, it returns whenever you increase your training.
A large study published in the British Journal of Sports Medicine in 2025 offers a useful perspective on why this might happen. The researchers looked at what happened when runners went further than they had in any single session during the preceding month, and compared that with changes in their total weekly mileage.
What the study found
Researchers followed 5,205 recreational runners in an 18-month study, analysing data from more than 588,000 running sessions recorded using Garmin devices.
They compared three ways of measuring increases in running distance, including changes in weekly mileage and changes within individual running sessions. The most significant finding concerned the distance covered in a single run.
10%
When runners exceeded their longest run of the previous 30 days by more than 10%, they experienced a higher rate of reported overuse injuries.
The association was particularly strong when runners more than doubled their recent longest distance. In those circumstances, the rate of injury was more than twice that of the comparison group.
Week-to-week changes in total running distance did not show the same association with injury rates. This challenges the traditional emphasis on weekly mileage as the main measure of training progression, and suggests the demands of an individual running session deserve more attention.
There is an important distinction, however. The researchers identified an association between sudden increases in distance and injury. They did not establish that exceeding 10% causes an injury, or that staying below 10% guarantees safety.
Read the original study: How much running is too much? (2025)
What does this mean for your next long run?
One practical way to use the research is to look at your longest run over the previous 30 days before deciding how far to run next.
Longest run in the past 30 days
Distance with a 10% increase
10 km
11 km
15 km
16.5 km
21.5 km
23.2 km
30 km
33 km
These figures are reference points to guide your planning, and they will sit differently for each runner. A runner who recently completed 20 km comfortably may respond quite differently to a 22 km run than someone who managed 20 km while already fatigued, recovering from illness or experiencing discomfort.
Repeated increases also add up. Extending your longest run every week without enough recovery can build into a substantial training load. Before any step up, the more useful question is whether you’re adequately prepared for the distance you’re planning.
Returning after a break
Take particular care when returning to training after illness, injury, travel or a period of reduced activity.
Your running history might show that you completed 25 km three weeks ago, but that doesn’t necessarily mean you’re ready to repeat it today. The 30-day measure tells you your previous longest distance. Your current readiness shows up in how much running you’ve maintained, how you’re recovering and how you feel during easier sessions.
Preparing for the race
If your longest training run was 15 km, completing a half marathon involves running approximately 40% further. That is a substantial increase, although it doesn’t automatically mean your preparation has been inadequate.
This is especially relevant to marathon training, where the longest training run is commonly shorter than the full 42.2 km race distance. Race preparation needs to take in your broader training history, endurance, pacing, nutrition and recovery.
Distance is only part of the picture
Although the study focused on running distance, the physical demands of running involve considerably more than kilometres alone.
Running 15 km on a flat, familiar route at a comfortable pace isn’t necessarily equivalent to covering the same distance over unfamiliar hills, technical trails or at a substantially faster pace.
Strength, training experience, previous injuries, fatigue and recovery may also influence how a runner responds to their workload.
Keep a simple running and symptom log
If you’re dealing with a recurring niggle, a brief record of your training and symptoms gives you something concrete to work with. You don’t need an elaborate spreadsheet or specialised software. A few notes in your phone after each run may be enough.
Record:
- Distance: how far you ran and how it compared with your recent longest run.
- Training conditions: pace, hills, terrain and any changes from your usual running.
- Symptoms: when discomfort started, where you felt it and whether it improved or increased as you continued.
- Recovery: how you felt later that day and the following morning.
- General fatigue: sleep, other exercise and anything else affecting your recovery.
After several weeks, you may begin to recognise patterns. Perhaps your discomfort repeatedly appears after extending your long run, or when you combine longer distances with faster training sessions. Alternatively, the symptoms might continue even when your running distance stays relatively consistent.
A log can show relationships that help guide your next decisions, and it gives a clinician a clearer account if you do need an assessment.
When a recurring problem needs a closer look
Reducing running distance or allowing more recovery may help some problems settle. When discomfort keeps returning despite sensible changes to training, there may be more to investigate.
In my clinical work, the starting point is understanding the runner’s experience. That includes their training history, how symptoms developed, what makes them better or worse and what they’ve already tried.
From there, I look at movement and structural relationships that may be relevant. Depending on the presentation, this might include ankle mobility, hip movement, single-leg control or how different parts of the body contribute to a particular movement.
An observation is only the beginning. Finding a restriction or an asymmetry doesn’t establish that it is responsible for the runner’s symptoms. The next step is to test whether that finding is relevant, consider what might be contributing and assess what changes following an appropriate intervention.
That intervention may involve hands-on work, movement education or a discussion about modifying training. We then recheck the response, both in the session and as running continues, since an improvement on the table may not carry over into running. If the original explanation doesn’t hold up, we reconsider it.
Where Rolfing fits
Rolfing Structural Integration combines hands-on soft tissue work with movement education.
For runners, this may involve exploring how the foot and ankle, lower limb, pelvis and trunk contribute to movement, depending on what the assessment reveals. The intention is to investigate whether there are modifiable restrictions or movement options relevant to the individual runner, without imposing an ideal posture or movement pattern.
Research specifically examining Rolfing for running injuries remains limited, and I wouldn’t suggest that hands-on treatment alone can prevent injury or guarantee an improvement in running performance.
Sometimes the most useful recommendation is to adjust training distance, improve strength or allow more recovery. At other times, further medical or physiotherapy assessment may be appropriate.
Know when to stop
Most running niggles aren’t serious injuries. Persistent or worsening pain still shouldn’t be treated as something to push through.
Arrange an assessment with a qualified health professional if you experience:
- Pain that persists or becomes progressively worse.
- A limp or noticeable change in the way you walk.
- Pain during ordinary walking or everyday activities.
- Marked tenderness in one specific area, particularly over a bone.
- Pain at rest or at night.
If pain is severe or you cannot bear weight, seek prompt medical assessment.
Bone stress injuries in particular require a different approach from ordinary muscle soreness. Continuing to run on a suspected bone stress injury can make the problem worse.
Before your next long run
Check your longest run from the past month. Think about the size of the step up, how consistently you’ve been training and how well you’re recovering. If a niggle keeps returning despite sensible changes, keep a log and get it assessed.
Nicholas Barbousas
Nicholas has practised Rolfing Structural Integration for more than thirty years, and has taught structural assessment to practitioners for most of that time. He sees clients at Rolfing Melbourne in Clifton Hill.
If you’re experiencing a recurring running problem and would like to explore whether Rolfing Structural Integration is appropriate for you, you’re welcome to arrange a session.
Research reference
Frandsen, J. S. B., et al. (2025). How much running is too much? Identifying high-risk running sessions in a 5200-person cohort study. British Journal of Sports Medicine, 59(17), 1203–1210. https://doi.org/10.1136/bjsports-2024-109380
Rolfing in Clifton Hill
167 Queens Parade, Clifton Hill VIC 3068
I see clients at a multidisciplinary clinic on Queens Parade, close to Fitzroy North, Northcote, Collingwood and Abbotsford. Sessions run for 60 minutes.
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