While running is not necessarily bad for the knees, poor form and injury may affect performance.

Knee pain due to running is a common injury, and approximately 50% of runners report injuries due to accidents or overuse per year.

However, running itself may not cause knee pain, but running excessively or with poor form can cause knee pain.

Running is an exercise that can help:

  • reduce stress
  • improve mood
  • help with thinking and cognition

Despite these benefits, running may be hard on the body and can sometimes affect the joints.

This article provides an overview of the effects of running and the risk factors to consider. We also explore possible conditions that may develop from running and ways to manage and prevent pain from occurring.

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Running can have a positive impact on both physical and mental health. Several studies have investigated the impact of running on overall health and how it affects joints and the development of certain conditions.

Long-distance running

Long-distance running is a popular exercise and has positive effects on the body.

A 2020 research review investigated the impact of long-distance running on developing osteoarthritis (OA), a degenerative joint disease.

The review concluded that those who run recreationally have a lower risk of developing OA than those who run competitively.

Similarly, a 2019 study evaluated the short-term impact of marathon running on knee joints that had pre-existing damage. The study compared participants before and after running a marathon using MRI scans.

The results showed reductions in damage to a person’s shin bone and thigh bone in the lower leg after running a marathon. There was increased damage to the knee cartilage, but this did not produce symptoms in participants.

Despite these findings, this study used a small sample size and focused on middle-aged novice marathon runners. More research must explore wider samples across different ages for more conclusive evidence.

Runners vs. non-runners

Several studies have also evaluated the long-term effects of running by comparing runners with non-runners.

A 2020 study investigated the effect of running on knee cartilage and found that a “cartilage conditioning” process occurs. In those who run recreationally, knee cartilage adapts to withstand the force of running and promotes long-term joint health.

A 2017 study investigated cartilage conditioning in runners versus a non-runner group. The results showed that a substance called knee cartilage glycosaminoglycan — which is responsible for shock absorption and lubrication — is higher in runners than non-runners.

Running form

Proper running form includes the following:

  • looking ahead
  • relaxing the hands and shoulders
  • keeping the arms below the chest
  • minimizing the force at which an individual hits the ground
  • keeping the knee in line by making sure the foot strikes under the knee, not in front of it, especially when running downhill
  • shortening stride, and landing with the knee slightly bent, which can take up to 30% of the load off the joint

Bicycling and doing core strengthening exercises can also support proper running form. Bicycling can help speed recovery by strengthening the quads, and core strength makes it easier to stay upright and avoid leaning forward from the hip when running, which prevents injury.

Types of ground and slope

Types of ground people run on and the slope can affect knee pain. Generally, running on a softer and flatter surface — such as grass, woodchip, or a treadmill — can help lessen the impact on the knee and prevent pain.

Shoe type

Finding a shoe that fits well, is comfortable, and provides good support can help prevent injury and avoid pain.

Choosing the right pair will also depend on an individual’s gait pattern. If a person has an injury, they may have an abnormal gait.

Lifestyle factors

Since running is a form of exercise, it is important to consider the lifestyle factors that can affect performance.

Factors that may significantly reduce the risk of injury include:

  • staying hydrated
  • preparing a progressive running program
  • maintaining a moderate weight
  • making sure to warm up before and cool down after running

Experts associate several conditions with knee pain due to overuse or misuse. Different structures in the knee can cause different types of pain, including the following:

  • Iliotibial band (IT) band syndrome: This is the second most common running injury. The IT band is a tendon connecting the knee to the hip to help stabilize it. This syndrome occurs when the tendon becomes irritated and inflamed due to repetitive movement, causing it to tighten.
  • Patellar tendonitis: This is inflammation of the patellar tendon and occurs in people who participate in activities that require running or jumping. Although it is more common in runners, doctors often refer to it as “jumper’s knee.”
  • Patellofemoral pain syndrome (PFPS): Doctors sometimes refer to this as “runner’s knee” due to overuse, trauma, or kneecap malalignment. This is common in people who participate in sports.
  • Chondromalacia patella: This is an injury resulting from damage to the articular cartilage. The cartilage in the knee begins to soften, resulting in inflammation and pain. Muscle misalignment, overuse, or injury may cause this condition.
  • Prepatellar bursitis: This condition occurs when the sacs between the bones and soft tissue, known as the bursa, become inflamed. This may result from a direct trauma like a fall during running. When swollen and irritated, the bursa puts pressure on the rest of the kneecap, causing pain.

A person can easily treat knee pain at home most of the time. For example, some methods include:

Find out more about home remedies for knee pain.

However, if the pain persists, it is best for a person to seek a doctor’s advice. They may recommend strong NSAIDs if the pain does not resolve. Depending on the cause, they may also recommend physiotherapy or steroid injections. Doctors reserve the latter treatment for people who have osteoarthritis.

In addition to physical exams and taking a medical history, doctors can perform diagnostic tests. These tests take a deeper look into the structures in the knee to help diagnose conditions. These include:

In cases where conservative methods do not provide relief, patients may undergo more invasive treatment methods, such as arthroscopy, a surgical procedure.

Strengthening the knee and improving flexibility through exercises for its supporting muscles can help prevent pain and improve running form.

A doctor or a physical therapist can suggest the most suitable exercises for a person to try. Some of these exercises may include:

  • hamstring curls
  • stepups
  • straight leg lifts
  • wall squats
  • quadricep stretches

Additionally, there are several measures a person can take to prevent knee pain from occurring. These include:

  • improving running form
  • wearing good running shoes
  • using compression wear, such as a knee sleeve
  • warming up and cooling down appropriately
  • doing strength training
  • training conservatively

Various factors may contribute to the development of knee pain and associated conditions. While many studies show the beneficial effects of running, a person must ensure their form is correct to avoid developing conditions such as IT band syndrome, patellar tendonitis, and PFPS.

To enjoy running and to do so safely, having good form and suitable garments, training conservatively, and focusing on strengthening and conditioning of the knees can prevent pain.