Here’s Why Your Knees Are Probably Hurting During Marathon Training

Written by Kelsie Mazur, DPT

If you’re training for the Chicago Marathon and your knees have started to hurt, you’re not alone. I see this pretty often with runners, especially when mileage starts increasing and those long runs get longer. The good news is that knee pain doesn’t automatically mean you’ve damaged your knee. More often, it can be a sign that the demands of your training have increased faster than your body has been able to adapt.

Think about what happens during marathon training: You’re gradually asking your body to run farther, more frequently, and sometimes faster. You may also be adding hills or speed workouts. All of these things increase the workload on your muscles and joints. Your cardiovascular system may feel ready to handle the extra miles, but your muscles, tendons, and joints may need more time to build the capacity to tolerate that workload.

Your long runs can be a big part of this. As you get farther into a run, fatigue starts to set in. Your muscles may not be able to control movement as efficiently as they could earlier in the run, which can change how forces are distributed throughout your legs. This is one reason a runner might feel fine during shorter runs but start experiencing knee pain during or after a longer run.

Another area I like to look at with runners is hip strength and stability. Your hips help control your pelvis and leg as you run, and that control becomes particularly important when you’re running on one leg at a time and dealing with fatigue. Exercises that work on hip strength and single-leg stability can be a valuable part of a runner’s training program. That doesn’t mean every runner with knee pain has “weak hips,” though. Knee pain is rarely that simple, and factors like training load, recovery, strength, mobility, and running mechanics can all play a role.

This is where seeing a Doctor of Physical Therapy can be helpful. Rather than trying to figure out the cause of your knee pain from a Google search, a DPT can look at the bigger picture. They can assess your strength, mobility, movement, running history, and training load to help determine what may be contributing to your symptoms. From there, you can work on the areas that actually need attention, which may include hip stability, lower-extremity strength, or modifications to your running program.

Recovery is another piece that is easy to overlook. Your body needs time to adapt to training, so stacking long runs, speed workouts, strength sessions, and everyday stress without enough recovery can make it harder to keep up. Sleep, nutrition, rest days, and easier training days are all part of preparing your body for the marathon.

So, if your knees start hurting during your marathon training, don’t immediately assume something is wrong with your knee or that you need to stop running altogether. Take a step back and look at the bigger picture. Has your mileage increased recently? Did you add hills or speed work? Are you recovering between harder sessions? Have you been working on your strength and hip stability?

The goal isn’t to have perfect running form or never experience an ache. It’s to build the strength and capacity your body needs to handle the demands of marathon training. If your knee pain keeps coming back or is affecting your ability to train, getting evaluated by a DPT can help you understand what’s going on and make a plan that allows you to keep moving toward race day.

Let’s chat! Book an assessment and let’s get you back to feeling good in your body.

No referrals, no waiting, just answers. Did you know that we offer free 1-on-1 injury screens? Wattage Physical Therapy will take an in depth look at your ergonomics, posture, muscle tone, muscle weaknesses, and movement patterns to create a plan for YOU. If this article intrigues you, you can directly email me, Kelsie at Kelsie@wattagept.com. I would be happy to help you start the process of living a life free from pain.