This is an excerpt from Strength Training 2nd Edition by NSCA -National Strength & Conditioning Association.
An injury occurs when a tissue (e.g., ligament, tendon, muscle, or bone) is subjected to an acute or chronic load that is too great. The damage triggers a response commonly referred to as inflammation. Inflammation is misunderstood and often seen as negative, when in actuality inflammation is a bodily response that removes injured tissue and repairs damage. When the body incurs an injury, a cascade of chemical reactions occurs as the body begins to repair the damaged tissue. Inflammation, heat, and redness often are symptoms of this healing process. Therefore, inflammation is the body's way of healing. However, acute inflammation is different from chronic or excessive inflammation, which often is a sign of a larger problem. If inflammation lasts longer than several days or is excessive in severity, you should see your doctor.
The general signs and symptoms of inflammation are redness, heat, pain, swelling, and loss of function. Pain indicates that an injury has occurred, and further stress will cause more damage. Swelling prevents normal function and creates a natural splint that protects the damaged tissue. However, each individual and injury are different, and signs and symptoms may not be present to the same degree. Signs and symptoms typically are more intense at the onset of injury and diminish as the injury begins to heal. Signs are objective indications of injury, whereas symptoms are subjective indications. For example, redness is a sign that a medical professional could see, but pain is a symptom that only the injured party can feel.
It is important to recognize any recurring signs and symptoms when considering a return to activity. Are signs and symptoms increasing, decreasing, or staying the same? If an injury is subjected to too much stress before it heals properly, the body may reinitiate the inflammatory response. No exact timetable for healing exists. Depending on the type of tissue and amount of trauma, signs and symptoms can increase for 48 to 72 hours and may persist for months or even years. Therefore, the old adage of "work through the pain" should be avoided when an injury has occurred.
The PRICE Method of Injury Management
PRICE is an acronym for a commonly accepted injury management protocol: protect, rest, ice, compression, and elevation. The PRICE protocol can be enacted when an injury presents with excessive pain, swelling, or inflammation. Protect the injury from further stress or loading. Although swelling creates a natural splint, the area can be protected further with the application of padding or a brace. Rest the injured area to prevent further trauma and to allow the healing processes to occur. Ice provides pain relief and other anti-inflammatory effects. Compression, generally with an elastic bandage, helps resolve swelling. Elevating the body part above the level of the heart counteracts the effects of gravity and supports the gains of rest and compression.
The practice of PRICE is warranted in the acute management of injury, but modifications may need to occur as healing progresses. For example, active motion helps align healing tissues and should be incorporated as signs and symptoms begin to lessen. Although it is critical that injured tissues are provided an ample amount of rest to heal, active rest can help prepare the body to return to activity as well as prevent excessive loss of muscular gains due to immobilization or decreased loading.
The application of ice or other cold agents has been shown to reduce the temperature of the surrounding tissue, causing vessels to constrict and nerve conduction to decrease. Although this helps attenuate the symptoms of inflammation, constricting vessels can lead to decreased delivery of the substances necessary for healing and may impede the process. No definitive evidence suggests that cold agents are detrimental; at the same time, no evidence shows that they are beneficial in injury management.
Dealing With Muscle Soreness
Unfortunately, muscular soreness is something that often comes with the territory when you begin resistance training. This soreness is the result of the muscle undergoing unfamiliar stress. Although the actual physiological processes involved in producing this soreness are not completely understood, the most likely theory is that unaccustomed exercise actually leads to microscopic tears in the muscle cells. These tears produce swelling, pain, inflammation, and loss of motion in the muscle, leading to decreased or altered function and to stiffness. These symptoms can begin as soon as a few hours after a resistance training session but often will not peak until 48 to 72 hours later. For this reason, the soreness associated with any type of resistance exercise is referred to as delayed-onset muscle soreness (DOMS).
The lack of understanding of the specific processes resulting in DOMS provides us with little ability to treat or prevent it. Rather, we attempt to manage the symptoms of pain and swelling. Ice, heat compresses, stretching, and ibuprofen have been used to treat DOMS. Unfortunately, none of these regimens have resulted in universal success.
One thing we know about DOMS is that it occurs to a lesser and lesser degree as resistance training is repeated. This is known as the repeated bout effect. Although you may experience significant discomfort after your first few training sessions, this discomfort is drastically reduced as you continue to train.
DOMS occurs to a greater degree when exercise is intense and is especially evident after intense eccentric training. Therefore, it is recommended that beginners work out with less intensity than intermediate and advanced lifters and minimize eccentric muscle actions in their routines. There is no reason for beginners to start their training with high-intensity workouts when they can accomplish significant gains with lower intensities and, in doing so, reduce the degree of DOMS.
It generally is recommended that lifters wait for the soreness of a prior workout session to fade before lifting again. DOMS acutely reduces strength and diminishes effort, which decreases the quality of a workout and increases the chance of injury. A lifter will be able to return to training without decrements in strength once the soreness is resolved. However, strength and DOMS return to normal levels at different times. Therefore, DOMS is not always a valid indicator of when to return to lifting. Research has shown that although strength may return to normal after 24 to 48 hours, DOMS may persist for 72 hours or longer, especially in beginners.
Learn more about Strength Training, Second Edition.