During recovery, patients often ask the question “should I use heat or ice?” My response is usually that it will vary from person to person dependent upon their specific injury with a few general rules to determine which will be more beneficial. To make an educated decision, we need to first understand how the body heals after injury.
When the tissues in the body break down, from micro traumas or from substantial damage like fractures, sprains or strains, the immune system kicks into action activating the body’s natural defenses. We see these defensive measures in the form of inflammation, increase in temperature to the damaged area, and redness from an increase in blood circulation. These factors are an attempt by the body to protect the area from further damage followed by removing the damaged cells before rebuilding new tissue. The initial inflammation response phase of healing begins immediately and lasts between three to five days. Once the debris from injury is cleared, the body can repair and rebuild the damaged structures over the next six to eight weeks. While it would be nice to have a solid, continuous timeline during healing, it is rarely the case for us as active individuals since the objective of strength training is to create cycles of breaking down tissue and recovering to rebuild stronger muscle. The soreness and discomfort felt after an intense workout is the sign that cells in the muscle tissue broke down causing a cascade of chemicals to release.
It is at this point in the healing process that we might choose to utilize Cryotherapy. Cryotherapy, or “cold” therapy, is the practice of using low temperatures to help the body heal and reduce pain. The belief is that by introducing cold temperatures to the injured area will reduce the metabolic processes that cause cell death and therefore prevent soreness and pain. For more substantial injuries, the evidence that applying cryotherapy to reduce swelling is less conclusive. The RICE principle of rest, ice, compression, and elevation has been common practice in injury management without any significant studies to support the true effectiveness. Recent studies have shown that cryotherapy has subjectively reduced pain while ice and compression in combination with prescribed exercise is the most effect way to reduce swelling. Therefor, our first rule is that cryotherapy might be most effective if 1) the initial injury happened within the last 72 hours, 2) swelling is present, or 3) if you are immediately post exercise. Cryotherapy comes in many different forms, such as: artificial ice packs, cubed ice, frozen vegetables, cold compression units, or total body cryotherapy chambers.
Once the initial stages of healing are complete, we may start to discuss using heat. The purpose of using heat as a modality is to help alleviate pain and tension by relaxing the tissue. Evidence in sports medicine and physical rehabilitation shows that heat intervention coupled with exercise to promote an increase in range of motion leads to quick recoveries after injury. One inefficiency we often see during the body’s healing process is that the fluids creating swelling in the injured area may not recycle into the body adequately leaving “debris” from the injury in the open spaces of the tissue. These leftover substances can lead to more discomfort and restriction in motion preventing the body from recovering fully. We often label these injuries as chronic. Chronic injuries are physical injuries or illnesses that last longer than a few weeks, occur multiple times, or have a more gradual onset, such as; low back pain, ‘Shin splints’, and muscle strains. Introducing heat at the sight of chronic injuries that may be described as “tight”, “stiff” or “ache” will help to make the tissue more subtle and promote circulation allowing the healing substances to move more freely and appropriately. Chronic injuries that are the result of multiple, subsequent injuries are generally caused by a biomechanical or movement pattern leading to recurrence. These chronic injuries should not be treated with heat initially as the body will repeat the healing process starting with the inflammation and protection to which we refer to our rules of cryotherapy.
Science and explanation aside, my general recommendation is summarized by one question: When and what caused this episode of pain? If the answer is an single event within the last 72 hours, you may benefit more from cryotherapy. If the event occurred longer than two to three days ago or it is a more insidious onset, you may benefit from heat therapy. As always, you should consult with a licensed healthcare professional who can make a recommendation for your individual case and couple heat/cold therapy with prescribed exercise.