Achilles pain is one of the lower-leg patterns runners should record with more precision than "my calf hurts". The useful details are location, timing, intensity, recurrence, and what changed around the run.
A 2024 prospective cohort in the Journal of Sport and Health Science followed 3,379 recreational runners for an average of 20.4 weeks. New-onset Achilles tendinopathy appeared in 4.2% of runners. The strongest signal was not one single training-load number; it was a history of Achilles tendinopathy during the previous 12 months.
The study at a glance
- Design: prospective cohort study of recreational runners
- Population: runners registered for running events in the Netherlands
- Participants included in analysis: 3,379
- Mean follow-up: 20.4 weeks
- Data collection: baseline and follow-up questionnaires around event preparation
- Outcome: new-onset Achilles tendinopathy, separated into insertional, midportion, and combined patterns
- Location method: a pain map was used to help classify insertional and midportion Achilles tendinopathy
This design is useful because it looks forward from a baseline, rather than asking injured runners to remember everything after the fact. It still cannot prove what caused one runner pain. It can show which measured factors were associated with new Achilles problems in this event-running cohort.
How often did new Achilles tendinopathy appear?
During follow-up, 141 runners developed new-onset Achilles tendinopathy. That was 4.2% of the 3,379 included participants, with a 95% confidence interval from 3.5% to 4.9%.
The study separated the location patterns. Midportion Achilles tendinopathy accounted for 63.8% of new cases, insertional Achilles tendinopathy accounted for 27.7%, and combined insertional plus midportion symptoms accounted for 8.5%. In plain language, not every Achilles complaint sits in the same place.
That location distinction matters for a runner history. The Dutch multidisciplinary guideline defines insertional symptoms as within the first 2 cm of the Achilles tendon attachment at the heel, and midportion symptoms as more than 2 cm above the attachment. A self-report app cannot confirm that diagnosis, but it can help preserve what the runner actually noticed.
Previous Achilles symptoms mattered most
The clearest risk signal was previous Achilles tendinopathy. Runners who reported Achilles tendinopathy in the past 12 months had 6.47 times the odds of new-onset Achilles tendinopathy during follow-up, with a 95% confidence interval from 4.27 to 9.81.
The association was similar for the subcategories: previous Achilles tendinopathy was associated with 5.45 times the odds of insertional Achilles tendinopathy and 6.96 times the odds of midportion Achilles tendinopathy. These are associations in a statistical model, not a personal prediction.
Training load was not a clean answer
The study did not find a significant association between the training-load measures it collected and new Achilles tendinopathy. The authors noted that future research should use more advanced serial measures of training load to test whether overuse is a risk factor.
This is an important limitation for runners. The result does not prove load is irrelevant. It says the measured load variables in this study did not explain onset clearly. A training block can still include meaningful context: sudden distance changes, hill work, speed sessions, shoes, surface, strength work, poor sleep, travel, or returning after time away.
That is why an athlete log should avoid false certainty. The goal is not to declare that one hill session caused Achilles pain. The goal is to preserve enough detail to compare repeated patterns and ask better questions if the symptom persists or escalates.
What runners should track when the Achilles area appears
A useful Achilles history starts with exact zone and timing. The back of the heel, the area just above the heel, and the middle portion of the tendon are not interchangeable notes. If the sensation is diffuse, record that too rather than forcing a neat label.
- Exact zone: insertional heel area, midportion tendon area, calf-Achilles junction, or diffuse lower-leg sensation
- Timing: during the run, immediately after, later that day, next morning, or after rest
- Intensity: use the same 0 to 10 scale each time so runs can be compared
- Recurrence: first appearance, returning zone, or same-side pattern from the past 12 months
- Context: distance, pace, hills, speed work, shoes, surface, strength training, fatigue, sleep, travel, or return after a break
- Function: whether normal walking, stairs, hopping, or planned training felt different
The location/history pair is especially useful here because the study itself used a pain map to classify Achilles tendinopathy patterns. Runners do not need to turn that into self-diagnosis. They can borrow the better habit: record where the sensation sits instead of treating the whole lower leg as one category.
When a tracking log is not enough
The Dutch guideline describes Achilles tendinopathy diagnosis as a clinical process involving localized symptoms, pain with sports loading, local thickening, and pain on local palpation. It also says imaging may be considered when symptoms do not fit the criteria, the course is unexpected, symptoms change during follow-up, or surgery is being considered.
For an athlete, that creates a practical boundary. A log can help you show what happened. It cannot tell you whether the tendon is injured, whether imaging is needed, whether a race is sensible, or which treatment is appropriate.
Seek qualified care promptly for sudden severe pain, a clear pop or rupture concern, rapidly worsening symptoms, major swelling, inability to push off, numbness, symptoms that alter normal walking, or pain that keeps returning despite load changes. Persistent Achilles-area symptoms are worth a professional conversation, not just more entries.
How TENSION fits a runner Achilles history
TENSION is built for self-report body feedback. Runners can paint the exact Achilles, calf, heel, ankle, foot, knee, or hip zone on a 3D body map, assign intensity, save the session, and compare entries over time.
That does not diagnose Achilles tendinopathy or explain cause. It does make a recurring-zone history easier to review. If the same lower-leg area appears after several hill sessions, after a shoe change, or during a return-to-running block, the record gives you a cleaner basis for deciding what to discuss with a physiotherapist, doctor, coach, or other qualified professional.
- Map the Achilles zone immediately after the run and again the next morning.
- Compare left and right sides instead of storing both as generic calf pain.
- Keep prior Achilles episodes visible when planning a new training block.
- Bring the body-map history to a professional conversation instead of relying on memory.
Read the prospective cohort study - Chen W, Cloosterman KLA, Bierma-Zeinstra SMA, van Middelkoop M, de Vos RJ. Epidemiology of insertional and midportion Achilles tendinopathy in runners: A prospective cohort study. Journal of Sport and Health Science. 2024;13(2):256-263.
Read the Dutch multidisciplinary guideline - de Vos RJ, van der Vlist AC, Zwerver J, et al. Dutch multidisciplinary guideline on Achilles tendinopathy. British Journal of Sports Medicine. 2021;55(20):1125-1134.
Build a clearer lower-leg history
See why exact location history matters, compare the pattern with knee pain in marathon runners and the running-form evidence review, and use session context notes before a professional conversation.
Read the TENSION editorial policy for how these evidence summaries are produced.
Explore TENSION's 3D body-map pain tracker for runners