Heating Pads for Muscle Pain Relief – 4 Questions Answered
There are times when either heat or ice can be helpful in reducing pain and encouraging healing during the body’s recovery process from muscle pain or soreness. When it comes to the application of heat via heating pad, there are multiple health and safety considerations to make so that one can ensure they aren’t making the injury worse, prolonging recovery, or introducing other bodily injury risks into the equation. Below are answers to four commonly asked questions about the use of heating pads for the treatment of muscle soreness.
1. How does a heating pad work to help with sore muscles?
When muscles spasm and tighten, especially after an injury or vigorous exercise or activity, it closes or constricts the blood vessels. With delayed onset muscle soreness (DOMS) brought on by strenuous activity, the lactic acid produced gets further trapped by these constricted vessels. The application of heat in these cases, whether from a heating pad or hot bath, jacuzzi, or shower, dilates the blood vessels in the area being warmed and increases blood flow, bringing cells to help heal the affected area. These blood cells get more oxygen and nutrients to the site and aid in eliminating the bad stuff (like lactic acid) from the affected area, which ultimately helps eliminate muscle pain and soreness. The application of heat can also facilitate the stretching and loosening of tight muscles, thereby helping to alleviate stiffness around joints. Think of it like this: imagine heating mozzarella sticks in the oven. They are much more pliable when warmed up.
There is also a role that heat is believed to play in the gate theory of pain. Simply put, different nerves carry different messages (hot, cold, pressure, pain) from an area of the body to the brain. The brain puts all those messages together, and we then experience the sum of those messages as a sensation. If we are experiencing terrible muscle aches from a rigorous hike or HIIT workout, those muscles have their pain receptors activated and working full time to send constant pain signals back to the brain. When we apply heat to the area that is hurt, we activate different nerves to transmit this new, non-painful message to the brain, whose message can deaden or lessen the underlying nerve pain messages.
2. If heating pads can be helpful in some cases, what type of heating pad is best?
Don't get hurt! Heating pads can cause severe burns if they get too hot or stay on one body area too long. Electric heating pads use household current to produce heat. Consider a heating pad that either escalates heat settings so you can start at a lower stage and adjust as needed. Automatic shut-offs or pre-set timers are additional features to consider, especially if there is an undesirable chance of accidentally falling asleep with the heating pad on. Having a cover or some fabric between the device and your skin will also help to prevent burns. Beyond burn concerns, electric heating pads can also create a fire hazard or electrocution issue. Avoid one with multiple wires and always keep it away from water.
Moist heating pads use water to dampen the pad before placement on the skin. They can reach very high temperatures and are often used by physical therapists for heat therapy. It is best to avoid this type of heating pad for home use to not accidentally burn oneself. One of the safest heating pad types to consider is the disposable heating wrap or pad. These can be found in most drug stores and can be used for easy, convenient, and safe heat therapy, which can be applied to almost anybody region.
3. Is it ever ok to fall asleep while using a heating pad?
Falling asleep while using a heating pad should always be avoided. Whether it's heat or ice, for that matter, there is no need to fall asleep with either on the skin as both can cause severe and disfiguring burns. While you are sleeping, your body is doing its job of recovering. Let the natural recovery do its job. If you are in an area of extreme cold and need added heat, make sure the heating pad is covered by cloth or a towel to create a barrier between the pad and your skin to avoid burns. Some circulating hot water pads can be used at night.
4. When applying a heating pad to any area of the body, how long is best?
Though there are no specific rules about the length of time to use a heating pad, it should stay on for about 10-30 minutes to be effective. If on for too short a time, the muscle or joint may not have an opportunity to warm up and experience pain-relieving benefits. Yet, leaving a heating pad on for too long can result in injury from burns and can potentially create a scenario of extreme inflammation in the body as the dilated blood vessels bring pro-inflammatory cells to the area warmed. While heating pads can absolutely play a role in helping a muscle injury to heal, they must be used with extreme care and caution. Ensure you don’t fall asleep while using one and that you don’t use it for too long, or allow it to get too hot in one body area. With safety precautions considered, the use of a heating pad can be a helpful tool for muscle pain relief.
8/5/21 Email containing answers by Dr. Trentacosta to questions from VeryWell Fit.