By Raechel Bugner DPT, FAFS
If you’ve been sidelined by injury recently, or are constantly dealing with nagging pain, it’s helpful to look beyond the training and rehab for clues as to why your injury doesn’t heal as planned. What if you’re doing all of the stretches, foam rolling and strengthening exercises your PT or running magazine recommends, and you continue to experience nagging pain? Maybe it’s time to examine your sleep habits.
Sleep plays a critical role in the body’s ability to repair tissue damage, build energy stores and stimulate brain function.
At the conclusion of a two-year study, the National Sleep Foundation released a report recommending that, in order to reap the restorative benefits of sleep, adults aged 18-64 need 7 to 9 hours of slumber. However, according to a report released last year by the Center for Disease Control, 1 in 3 adults are not getting this suggested amount of shut eye.
How does any of this affect your running injury?
Sleep plays a vital role in the body’s immune response. Studies have demonstrated that healthy individuals who are deprived of sleep (less than 6 hours per night) will present with an increase in white blood cells, specifically neutrophils. Neutrophils are typically the first responders to injury or infection and play a critical role in kicking off the inflammatory process.
While it may seem great to have your immune system revved up and ready to fight infection, high levels of neutrophils that are present over prolonged periods of time (several days of poor sleep) are actually contributing to chronic inflammation, which can lead to diseases such as diabetes, heart disease and high blood pressure — none of which are favorable for your health. Chronic inflammation can also affect your body’s ability to heal from your running injury.
The inflammatory response is a normal step in tissue repair following injury; its goal is to help remove damaged tissue to allow for healing to occur. This stage of healing should only last for about a week with peak inflammation occurring within the first 1-2 days after an injury. If the inflammatory phase persists longer than normal, the subsequent two stages of healing cannot occur, and your running injury will continue to nag you.
So let’s summarize: individuals who continually get less than 6-7 hours of sleep a night already have higher-than-normal levels of neutrophils stimulating inflammation throughout the body, which prevents the actual area of injury from moving into the last several steps of healing (and prolonging that pain in your knee).
Lack of sleep also prevents tissue repair and muscle growth from occurring. During the deepest stage of sleep, blood flow to your muscles increases, growth hormone is released which contributes to muscle growth, protein synthesis occurs and your energy stores are replenished. These processes occur primarily while sleeping — so if you’re not getting enough shut eye, you’re seriously missing out on key mechanisms necessary for injury healing.
Those late nights in the office also affect your running performance. As we discussed above, the deepest phase of sleep helps to replenish the body’s energy stores. It also increases the production of glycogen — the stored carbohydrates that are utilized for energy during exercise. When we have late nights and early mornings, we also change the body’s glucose tolerance and carbohydrate metabolism, which alters the supply of energy to our muscles.
If energy provisions are depleted and your body is prohibited from creating new stores, the time it takes for you to reach exhaustion while out for a run decreases, and your performance suffers.
Now that you know how much your sleeping habits are affecting your chronic knee pain, here are a few tips for getting a restful night’s sleep:
#1- Set an Alarm … For Bed!
Count backwards from the time you need to wake up and set an alarm in your bedroom to go off approximately 7-9 hours prior to your desired wake time. If you’re caught up in a TV show or work, this will be a good reminder to start winding down; plus you’ll be forced to head into your bedroom to shut the alarm off, which should help you start your bedtime routine.
#2- Read a Book
Ever lay down at night and suddenly all you can think about are the millions of things on your “to do” list or the dozens of deadlines you have at work? If distracting thoughts make it difficult to get the shut eye you need, try picking up a favorite book. Reading may help take your mind off of the stressors that make it difficult to fall asleep, and it may also help to tire out your eyes. Just make sure your book is a hard copy and not downloaded to your iPad; research shows that the bright lights from electronic devices can suppress melatonin (the hormone responsible for making you sleepy).
#3- Your iPhone Needs Some Rest Too!
Charge your phones and devices far away from your bed. This will prevent you from sending after-hour work emails or engaging in a late night group chat with your friends. And, just as we mentioned above, the light from your phone screen disrupts the release of melatonin, which helps make you tired.
#4- Take Some Time to Meditate
Just as reading helps to distract your mind from worrying thoughts, meditation can help take your mind off of the stressors that keep you up at night. Try focusing your thoughts on your breathing, the rising and falling of your chest or a word or phrase. Anytime your mind begins to wander, bring it back to your breathing or your mantra; before you know it, you’ll be sound asleep!
The next time you’re frustrated by a persistent running injury, remember that the amount of sleep you get is just as important as the amount of stretching and strength training in your body’s ability to heal.