Ice vs. Heat
Which to use and when?
I often get asked about whether it’s better to use ice or heat when caring for a sore muscle or injury. As with so many things in the human body, the answer is that it depends…
A good rule of thumb is that if something just happened, use ice for the first 24-48 hours. For example, if you just lifted a heavy box and “tweaked” something in your back or you went for a long run earlier today and now your achilles is sore, this is the time to ice.
However, if something is persistent for several days, you may find heat useful. For example, if the muscles in your back have been tight for several days, or a few days ago you went for a long run and your achilles is still sore, now is the time to use heat.
Heat and ice share a lot of similar physiologic benefits, however, the shining glory of ice is it’s ability to reduce the spread of acute inflammatory chemicals. Ice causes vasoconstriction, or a tightening of your blood vessels, which decreases circulation to the area of application which can help decrease the spread of inflammation; this is how ice decreases swelling. Heat, on the other hand, causes vasodilation resulting in an increase in circulation which can result in increased spread of inflammatory chemicals; exactly what we don’t want right after an injury has occurred, but helpful when we’re looking to clear excess metabolites from tissues several days after an injury.
Inflammation is often talked about in negative way, but it’s important to remember that inflammation is our body’s first step to healing; we need inflammation to jump start the healing process. While a little inflammation is good, too much inflammation gets in the way - those of you who have seen me for an acute ankle sprain have experienced the physical moving of inflammation out of the joint so we can create space for healing to occur. This is why it’s good to ice after an injury occurs for 24-48 hours. After 48 hours, the inflammatory chemical cascade as has calmed down and you can now use heat to help bring additional healing circulation to the area.
In summary, post-injury ice. Ten minutes if the ice pack is applied directly to the skin, or up to 20 minutes if you’re using a towel or other barrier between your skin and the ice pack. Be watchful for frostbite - it’s a real thing! Icing 10-20 min. every 1-2 hours can help break the inflammation cycle and get you on the road to recovery faster than if you didn’t ice.
If you have some persistent acheyness or it’s been a day or two after an injury, try heat. 15-20 minutes, using a barrier (towel) between you and the hot pack and be watchful for burns. After 20 minutes, the heat has had it’s effect and keeping it on does not promote any further physiologic benefit. Go move around or do something else, come back and heat things up again in an hour or two if needed.
My favorite ice pack is the Chattanooga ColPac. It gets super COLD, so stay watchful re: frostbite!
I also love this or an ace bandage for being able to hold an ice pack in place and move around while icing, although you still have to watch for frostbite.
For heat, my favorite option is a warm epsom salts bath, as moist heat penetrates into your tissues deeper than dry heat (an example of dry heat is a microwaved hot pack). Epsom salts are simply magnesium, a very relaxing and beneficial mineral for our bodies.