Hot or cold, which is better for my pain and recovery? A question that has been long debated, as the application of hot or cold may be appropriate under different circumstances. These circumstances may include the type of injury, timing of application and the duration of use with each treatment.
Heat therapy involves adding heat to the body and associated tissue whether through hot packs, water bottles, baths, packs with grains or electrical pads. Physiological effects include; increased blood flow, metabolism, elasticity of connective tissue and pain relief.
Research displays consistent evidence when using heat therapy for acute low back pain and delayed onset muscle soreness (DOMS), primarily by controlling pain, then decreasing stress and improving sleep. DOMS involves both mechanical and metabolic changes to muscles after exposed to exercise with onset at 24 hours and peak by 72. A new study has also shown that sore muscles following exercise treated with heat therapy compared to no intervention displayed both an improvement with fatigue resistance and an increase in factors regarding the generation of blood vessels within muscles.
Cold therapy, also known as cryotherapy, involves the application of any substance that removes heat and decreases the temperature of the tissues within contact. It is often applied via crushed ice, gel packs, ice massage, cold compression units and vapocoolant sprays.
Physiological effects of cold include; decreasing blood flow, swelling and metabolism, and to act as a local anesthetic.
Acute musculoskeletal injuries such as ankle sprains commonly receive cold therapy, as the inflammatory response of heat, swelling, redness and pain would logically benefit from the direct application of a cold substance.
Research shows that cold therapy for acute musculoskeletal injuries is primarily anecdotal, and quality evidence-based trials are currently lacking. Recent studies determining cold therapy with delayed onset muscle soreness (DOMS) after exercise is also conflicting.
Bottom line: Cold therapy may be beneficial with acute injuries with inflammation between 48 to 72 hours post injury, while heat therapy is recommended for both acute low back pain and muscle soreness by primarily decreasing pain.
Sources
Kim, K., Kuang, S., Song, Q., Gavin, T.P., & Roseguini B.T. (2019). Impact of heat therapy on recovery following eccentric exercise in humans. Journal of Applied Physiology. Abstract retrieved from the Journal of Applied Physiology. doi: https://doi.org/10.1152/japplphysiol.00910.2018
Malanga G. A. et al. (2015). Mechanisms and efficacy of heat and cold therapies for musculoskeletal injury. Postgraduate Medicone, 1, 57-65. doi:
http://doi.org/10.1080/00325481.2015.992719