Why Does Running Hurt at the Start but Feel Better Later?

Sometimes the first few minutes of a run feel stiff or painful, but after a mile or two the discomfort settles down and the run actually feels better. What does this mean?

As a running physical therapist working with runners in Atlanta, this is something I hear fairly often: “If the pain goes away during the run, is it okay to keep running?”

In many cases, the answer is yes, but with the right modifications. It depends on the type of tissue involved and how the pain behaves durning and after the run.

Why Pain Sometimes Improves During a Run

When you first start running, your muscles, tendons, and joints are transitioning from a resting state to movement. Tissues that have been relatively inactive, especially if you’ve been sitting at a desk or in the car. When you abruptly expose them to the lstess of running your body can feel stiff.

This pattern is particularly common with tendon-related injuries.

Examples include:

• Achilles tendinopathy

• patellar tendon irritation

• early plantar fascia pain

  
  

Tendons often follow a predictable 24-hour pain cycle. They may feel stiff or sore when you first start moving, improve as the tissue warms up and loads gradually, and then become sore again later in the day or the following morning.

This happens because tendons respond to mechanical loading. A moderate amount of load can temporarily reduce pain sensitivity even when the tendon is irritated.

The 24-Hour Tendon Pain Guideline

When runners are dealing with tendon pain, we often use a simple guideline to determine whether running is appropriate.

If you start your run with mild pain around 1–2 out of 10, and the pain increases during the run to about 4–5 out of 10, that can still be acceptable as long as the pain returns to baseline within 24 hours.

If symptoms settle back down by the next day, the tendon is usually tolerating the training load.

This approach allows runners to stay active while the tendon gradually adapts to stress.

Running injuries are often associated with training load exceeding tissue capacity, particularly when distance or intensity increases rapidly.

In many cases, modifying training rather than stopping completely can allow runners to keep moving while the tissue recovers.

A Dynamic Warm-Up Can Reduce Early Run Stiffness

If the beginning of your run consistently feels stiff or uncomfortable, a short dynamic warm-up can help.

A dynamic warm-up increases blood flow to muscles and tendons, raises heart rate slightly, and activates the nervous system before you start running. This prepares tissues for the repetitive loading that occurs during running.

A few minutes of movement can ease that transition from sitting and working to running.

Simple warm-up movements might include:

• brisk walking or easy jogging

• standing clam shell

• calf raises

• bodyweight squats

• lunges

  
  

These movements gradually load muscles and tendons while increasing circulation. As tissues warm up, they often tolerate running more comfortably.

Just Because It Feels Better Doesn’t Mean

It Isn’t an Injury

A common misconception among runners is that pain that improves during a run isn’t an injury.

That’s not always true.

Many early-stage running injuries follow this exact pattern, pain early in the run, improvement with movement, and soreness later in the day or the following morning.

Research examining thousands of runners shows that training characteristics such as weekly mileage, running frequency, and consistency play a major role in injury patterns.

When the body is exposed to more load than it can tolerate, small irritations can develop, even if they temporarily feel better during activity.

When Pain Is a Warning Sign

Not all pain patterns are safe to run through.

Some symptoms should be treated as a full stop, particularly when a bone stress injury (BSI), often called a stress fracture may be present.

Warning signs of a bone stress injury include:

• pain that gets worse as you run

• sharp, localized pain

• pain with single-leg hopping

• pain that progressively worsens day to day

Unlike tendons, bones generally do not warm up and feel better with activity. Continuing to run through these symptoms can allow the injury to worsen.

My Take Home Message

Pain that improves after the first few minutes of running is common, especially with tendon-related injuries.

In many cases, runners do not need to stop running completely. Instead, the goal is smart modification adjusting mileage, intensity, or terrain so the irritated tissue can recover.

Pain that returns to baseline within 24 hours may be manageable. Pain that continues to worsen, becomes sharp, or affects your ability to hop or run normally is a sign to stop and get evaluated.

Most running injuries don’t appear overnight. They usually develop when training load progresses faster than the body can adapt. Look back at your training over the last 4-6 weeks and see if anything has changed in your trianing or life that may be leading to your pain.

Listening to early warning signs and adjusting training accordingly is one of the best ways to stay healthy and keep running.

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