How to Tell the Difference Between Good and Bad Pain on Your Runs

Q: I’m training for a marathon right now—my first! I know that I’ll have to push my body during training, but I’m terrified of getting injured. What’s the best way to tell the difference between tired legs and muscles on the brink of injury? –Carla

This is a great question, and one that every runner should consider! The ability to listen to your body is the single greatest tool you can possess in order to successfully navigate the demands of marathon training. In the simplest terms: The better you understand your body, the better runner you can become.

The key is to learn when your body is telling you “I’m tired,” and when it’s screaming “Stop!” First, understand that fatigue is a necessary component of training. Running puts stress on muscles, causing the body initially to break down and later to repair itself. This is how you get stronger and faster.

“Good pain” is when you push just beyond your comfort zone—if you run a little farther or a little more quickly than your body is used to. If you finish a tempo run and your legs feel a bit heavy, this is normal and safe. Good pain goes bad when you become so tired that your form breaks down. If you have to compensate or alter your stride in order to finish a workout, you’ve just crossed over to the dark side.

To prevent bad pain from turning worse, watch for your body’s “yellow flag” alerts. Reconsider the tempo run scenario: One mile into your workout your right hamstring is hurting so badly that it creates a hitch in your stride. This is your body telling you to stop the run, walk home and take a few days off to let your leg recover.

In most cases, if you heed your body’s yellow flags immediately, you will only need a small amount of time to heal. Too often, a marathon runner is so nervous about finishing every single workout in her plan that she runs right through the yellow alerts into the red zone. When this happens, serious injuries occur—the recovery process may last weeks versus days, and can force withdrawal from a planned race.

Allow your body to be your guide and never ignore your yellow flags. Follow these simple tips to ensure you stay on the streets rather than the sidelines. . .

#1 Build a base before you start training.

If the first week of your training program includes a long run of eight miles, but the farthest you’ve run recently is only five miles—hold off. Start from your current fitness level rather than where the training program begins, and allow yourself enough time to build an adequate foundation. The stronger you come into the training season, the more likely you are to withstand the demands of training, recover optimally and succeed without aches, pains and injuries.

#2 Change up your pace.

Many runners fall into the trap of maintaining the same pace for every workout. In reality, your pace needs to ebb and flow. An easy run should always be completed at an easy pace, which will vary depending on how you feel on a given day. This may be a 10-minute-per-mile pace on Monday, but an 11-minute pace on Friday after you’ve had a stressful week at work. Base your pace on effort rather than your watch.

#3 Slow down for long runs.

Increasing your mileage puts stress on your body. You don’t want to burn the candle at both ends by running fast as well. Keep your long runs at a pace at which you can talk in complete sentences. Remember, this pace will vary based on the day and the elements. Train from within.

#4 Be wary of localized pain.

Sore legs are one thing, but a sore lower calf is another. Pay extra attention to pin-pointed discomforts, as these can often cause poor running form due to compensation.

#5 Never push through aches to stay on schedule.

Sure, your knee has a niggling ache, but you need to get in your speed workout this week. One more run won’t hurt it, right? Wrong! It’s a tough pill to swallow, but skipping the workout to allow your muscles to heal can be the difference between making it to the starting line and applying for a deferral. Cross train with a low-impact activity, stretch and self-massage until the bad pain goes away.

(Originally published in Women’s Running)