Knees Hurt After Running? Here's Why and What to Do About It
- 4 days ago
- 5 min read
Post-run knee pain refers to knee discomfort that develops after running rather than during the run itself. It often starts gradually and may feel like an aching pain around or behind the kneecap that becomes more noticeable with stairs, sitting, or bending the knee.
In many cases, post-run knee pain is related to overuse injuries, training errors, recovery deficits, or a mismatch between training demands and tissue adaptation. Addressing symptoms early with activity modification and Triathlete Physical Therapy can help prevent the condition from progressing.
What is Post-Run Knee Pain?
Post-run knee pain is pain that occurs after running but not during a run. It’s not usually associated with a specific injury. Instead, runners often notice that the knee gradually becomes more painful after running over days or weeks of training.
Some runners experiencing post-run knee pain might also have knee pain in the beginning of the run session that improves during the session, or mild knee pain at the end of the run that seems to worsen after they stop running.
The knee pain is usually described as an intense ache in the knee joint or behind the kneecap that feels extra tender when bending the knee (e.g. sitting, stairs, or even walking). It can affect one knee only, both knees equally, or both knees with one worse than the other.
New runners experience post-run knee pain more often, but it can also affect seasoned runners, especially when coming back from a break in training or during challenging training blocks.
While the knee pain may only occur after running initially, it can eventually progress to knee pain during running if the underlying issue is not addressed.
Common Causes of Post-Run Knee Pain
Knee pain after running is usually associated with an overuse injury. In many cases, the tissues in and around the knee become sensitive because they need more time to acclimate to the demands of running.
Common overuse injury diagnoses associated with the knees hurting after running include:
Patellofemoral Pain Syndrome or Chondromalacia Patella (Runner’s Knee) - pain is felt behind or around the kneecap and worsens with squatting, stairs, prolonged sitting, and downhill running
Patellar Tendinopathy (Jumper’s Knee) - pain is felt below the kneecap where the large patellar tendon attaches. It’s triggered by running and jumping but often improves as it warms up
IT Band Syndrome - pain is felt on the outer part of the knee and often starts towards the end of the run
Although these conditions have slightly different symptoms, they follow a similar pattern. Early on, you may only notice some knee pain after you finish running or mild knee discomfort that improves as you warm up. But if nothing is done to address this, over time you may experience knee pain that lasts longer after a run, begins earlier in the run, or starts affecting the entire run.
Training Mistakes That Can Lead to Knee Pain
Overuse injuries are usually the result of training errors and poor recovery.
This can include:
Increasing mileage before you’re ready
Not taking long enough breaks between run sessions
Poor sleep
Under-fueling
Increased life stressors
It’s important to remember that cardiovascular adaptations happen faster than joint and muscle tissue adaptations. So while you might generally feel ready to increase running time or mileage, the tissues in and around your knees might need more time to adapt.
Of note, if you are experiencing more aches and pains with running but your training and life stressors have not changed, you may want to determine how old your running shoes are. Worn-out (>300 miles) or incompatible running shoes can also contribute to new aches and pains with running, and changing your running shoes can be a relatively simple fix to try.
When to Rest and When to Keep Running
When talking about rest, it’s important to clarify that “rest” in this context means taking a break from running but still staying active by cross-training.
In most cases of post-run knee pain, you won’t need to completely stop running. But you will need to decrease your running volume to a manageable level before gradually increasing mileage again. This allows your knees to adapt to the demands of running.
A strategy for this can be determining how much running your knee can tolerate without pain and staying at that mileage for at least a week. This can look like running 3 miles at a time with two days of rest between running days.
Once you’ve had 3 or 4 run sessions, or about a week of running, without pain, you can increase volume by either increasing mileage or decreasing rest days between runs. Then maintain that new schedule for at least another week and continue gradually increasing from there.
While rebuilding your running volume, if the knee becomes cranky after one run session, you don’t necessarily need to modify anything yet. But if the knee pain returns after multiple sessions in a row, lasts a couple days after running, or is worsening, then you might need to spend more time at the previous mileage before trying to increase it again.
If your knee pain has progressed to the point that it’s painful throughout the entire run, or the pain lingers for more than two rest days, then taking a break from running and cross-training to give your knees a break might be warranted.
After about a week or two of cross-training, you can try returning to running with run-walk intervals to start and then gradually building up your mileage again as described above.
If you need help determining if you need to rest or with implementing a gradual progression or return-to-run plan, a Triathlete Physical Therapist can help.
Treatment and Recovery Options
First-line treatment for post-run knee pain is conservative care, such as activity modification and physical therapy. The goal of treatment is to decrease pain, improve your knee’s ability to tolerate running, and address any strength or mobility issues you may have.
While fixing your knee pain for the long term can take some time, there are a few things you can do to decrease pain in the short term.
Modalities such as electrical stimulation (e-stim), taping, and ice can help temporarily relieve pain. However, they will not help your knee adapt to the demands of running, so they are not long-term solutions for knee pain.
How Physical Therapy Can Help
A physical therapist can help determine the cause of your knee pain while also screening for anything that may require further medical evaluation.
During the assessment, the physical therapist will also look for any strength or mobility limitations that may be related to your symptoms. In many cases, pain itself can lead to decreased strength, making it more difficult for the tissues in and around the knee to tolerate running.
From there, a personalized plan will be developed with exercises to help decrease pain, improve strength and mobility, and gradually increase your tolerance to running.
Along with providing accountability, a Triathlete Physical Therapist can also help integrate your rehab with your training to ensure that your rehab continues to progress towards your training goals as your symptoms improve.
Triathlete Physical Therapy in Nevada
Whether you're training for a 5K, triathlon, or HYROX race, addressing post-run knee pain early can help you stay consistent with training.
If you're a triathlete in Nevada looking for help getting back to pain-free running, I’d be happy to help. I specialize in remote rehab for triathletes to help you recover without rehab taking over your life. Schedule a virtual movement assessment below to start getting back to running pain-free.
