It's really quite easy to explain without going into the deep biological science. It should be easy to understand why heat is better than ice. Let's look at what we know about how heat therapy works.
Superficial heat therapy is ideal for addressing musculoskeletal pain because (Freiwald et al., 2021):
it reduces pain signals
improves circulation (which ensures proper out-flow of bad stuff and in-flow of good stuff)
softens stiff myofascial tissues & improves range of motion = restores mobility
optimizes cellular metabolism in the affected area which speeds healing, removal of pain-inducing mediators (inflammatory cytokines), and uptake of nutrients/oxygen
That all seems like positive effects that address a complex set of problems that are causing the pain and discomfort one with chronic pain is dealing with, doesn't it? Why would you want to achieve the opposite effects with cold?
Let's consider what is happening in the body with chronic pain:
The myofascial tissues are stiffening, hardening, becoming dysfunctional and less capable of removing inflammatory compounds or taking in the nutrients/oxygen to ensure healthy cellular function/repair/regeneration. Blood and fluids are no longer efficiently moving through these tissues. Inflammation is stuck in the tissues. Pain signals are set off and create a pattern of expectation of pain and of generally feeling bad about the body/pain pattern that has formed. A person in chronic pain is discouraged from doing activities, further contributing to the stagnation, atrophy, and stiffness that leads to more persistent pain.
What if you could mitigate this process simply? Look at the list of effects of cold vs heat and answer which do you think would be better for chronic, persistent myofascial pain?
Heat Helps the Body
There has been quite a lot of research looking at the effects of heat therapies on the body and the tissues.
A summary of these effects can be read in the review paper by Kim et al. (2020):
To add to our physiological understanding of how heat benefits the muscles and arteries let's quickly summarize these effects in simpler terms:
Improved angiogenesis = creation of more vessels to deliver blood/oxygen and remove wastes/inflammatory materials from the tissues
Increased Enzyme Endothelial Nitric Oxide Synthase (eNOS) = heat helps improve effectiveness of nitric oxide in our blood, helping open blood vessels
Stimulates optimized mitochondrial function = improved muscle energy capacity
Optimize glucose metabolism & insulin sensitivity
While the authors address the variability of the results throughout the various types of studies done, there is a clear opportunity to use heat to improve myofascial health.
Ultimately - Experiment to Find What Works
It is our clinical opinion that 9 times out of 10, heat will be better for chronic pain.
When muscles and/or joints are stiff, painful, sore, tight, and generally response well to gentle activity/mobilization and massage/pressure, then heat therapy is going to help as well. This is most chronic musculoskeletal pain.
There are occasions where a muscle goes into spasm, pinches a nerve, and creates extreme, typically burning, stabbing pain. In this case, it makes sense to numb pain, reduce spasm, and calm the extreme inflammation, especially affecting the nerve, with ice/cold. We think of ice/cold as a short-term tool used for acute flare-ups or immediately after severe injuries. We generally recommend using ice and alternating with heat to return the tissues back to optimal blood flow, metabolism, and mobility.
It also makes sense to use NSAIDs or other anti-inflammatory herbs/medications to reduce the inflammatory pain. We would generally recommend using internal anti-inflammatory medications with heat, to get the benefits of both and avoiding the adverse effects of ice/cold on most tissues.
Ultimately, we recommend patients experiment and try both ice and heat, to see which helps their specific pain and injury. We always encourage patients finish with heat, for the reasons stated above. "Contrast therapy" or alternating cold and heat can create a helpful pain relieving, anti-inflammatory, and physio-mechanical 'pumping' of the tissues, especially if one ends with heat.
If you want our experience-rich advice and assistance with chronic pain, the licensed acupuncturists at Abundant Heaven Integrative Acupuncture are ready to help.
Freiwald, J., Magni, A., Fanlo-Mazas, P., Paulino, E., Sequeira De Medeiros, L., Moretti, B., Schleip, R., & Solarino, G. (2021). A Role for Superficial Heat Therapy in the Management of Non-Specific, Mild-to-Moderate Low Back Pain in Current Clinical Practice: A Narrative Review. Life, 11(8), 780. https://doi.org/10.3390/life11080780
Kim, K., Monroe, J. C., Gavin, T. P., & Roseguini, B. T. (2020). Skeletal muscle adaptations to heat therapy. Journal of Applied Physiology, 128(6), 1635–1642. https://doi.org/10.1152/japplphysiol.00061.2020
Malanga, G. A., Yan, N., & Stark, J. (2015). Mechanisms and efficacy of heat and cold therapies for musculoskeletal injury. Postgraduate Medicine, 127(1), 57–65. https://doi.org/10.1080/00325481.2015.992719