OK, I’m sorry for the really cheesy title, but I couldn’t resist. Anyway, what I want to talk about today is cold therapy or, as it’s more commonly known, ‘putting ice on it’. Icing an injury, as per the old RICE acronym (Rest, Ice, Compress, Elevate) has been one of those things you ‘just do’ ever since I remember doing exercise or playing sport. You go over your ankle running about like an idiot as a child, and a grown-up gives you a bag of frozen peas wrapped in a tea towel and tells you to told it on the joint to make the swelling go down. Furthermore, taking cold baths and shower seems to be a pretty well known tactic for post training recovery.
Well, it seems that this is probably not a good idea after all, we’ll start with icing injuries and the RICE principle.
One of the guys who originally coined the phrase, Dr. Gabe Mirkin who authored the bestselling ‘Sportsmedicine Book’ which contained the term in 1978 has now gone on the record as saying that his old recommendations may in fact delay healing(1). He presents a few different reasons for this.
First of all, the reason that ice should theoretically help heal injuries is that it blunts inflammation. The inflammatory response is the means by which your body is able to deal with threats – for example if you are infected with a potentially harmful microbe, an inflammatory response is initiated which effectively fills the area with specialised cells designed to fight off whatever the threat is and neutralise any danger. This same inflammatory system causes swelling which you would associate with, for example, the above mentioned ankle sprain. Unfortunately it’s also responsible for at least some of the pain, so it stands to reason that people have sought ways to alleviate it.
Inflammation causes swelling by dilating local blood vessels and making them permeable, which allows a sudden influx of fluid to flood the area in order to bring various special cells. Fibroblasts fill the area; cells which can synthesise collagen and begin the repair process. Inflammation also brings other cells known as macrophages which can release IGF-1 - necessary for rapid and effective damage repair. But when you ice it?
One study done on rodents indicates that by applying ice you effectively prevent this IGF-1 release, which can prolong the healing process significantly (2). What’s more, by preventing the swelling altogether, you actually stop this influx of fluid and therefore vital immune cells don’t arrive as abundantly as they should
Thinking about it, this actually makes a lot of sense. The inflammatory response of swelling the area has evolved for a very good reason and interfering with it is logically a poor move. Dr Mirkin still advises compression and elevation because these help to mediate the swelling without eliminating it, and they also don’t interfere with the actual inflammatory response itself. He notes that a very short immediate icing can reduce pain and therefore a 10 minute period is acceptable for injuries which are particularly painful. The ice should then be removed for at least 20 minutes to allow the area to warm and swell as it’s supposed to, then you can repeat the process one or two times more.
It’s worth noting that the exact same principle is why NSAIDs like paracetamol should be used sparingly during the healing process. If pain is excruciating then of course, use them for relief, but use them only as needed and not as a par for the course thing as they WILL prolong the healing process.
So no ice, but what else?
And, while we’re on the subject, should we completely rest an injury? Well, it’s a good idea to rest an injury immediately after it happens because to ‘not’ do so would be extremely painful and could, of course, carry the risk of worsening the damage – but complete rest is rarely a good idea.
This is because a mobile injury which is suitably weight baring will heal far faster than it would if completely rested – even if it’s a fracture(3). Consider that many surgeons won’t even cast a break anymore if they can avoid it in any way and you’ll see what I mean. Of course, the key here is SUITABLY mobile and weight baring. An ankle which has been sprained shouldn’t be jumped about with, but rolling the joint around gently (using your leg muscles to move the foot as much as is possible/comfortable, rather than grabbing hold of it and forcing it) then very gently weightbaring with it while walking on crutches will do far more for the affected area than leaving it immobile for 2-3 weeks waiting for complete healing, only to leave the joint weakened and the athlete (you) worried that it’s going to ‘go’ again.
When injured, rest it immediately, apply a bandage which compresses it and ice it for at most 10 minute intervals during the first hour or so. After that, start some kind of rehab. Done!
Ice baths – they suck, but do they help?
Injuries aren’t the only time when an athlete would consider using cold therapy, though. Ice baths have for a very long time been a staple recovery tool for athletes, but following the above logic (and a fair amount of scientific evidence) it might be time to ditch them altogether.
The idea is this. DOMS or delayed onset muscle soreness is caused at least in part by small amounts of muscle damage which you cause during a training session which go on to primote an inflammatory response (4). This damage is caused because of the mechanical structure of muscle tissue which is described by sliding filament theory which you may be familiar with:
Skeletal muscle tissue has a complex structure. Each muscle is surrounded by a sheath of connective tissue called the epimysium, which is itself surrounded by fascia. Within the epimysium there is a number of smaller units called fascicles which contain a bundle of muscle fibres and are surrounded by connective tissue called the perimysium. Within each fascicle is a number of individual muscle cells known as myofibrils or muscle fibres which are surrounded by sarcoplasmic reticulum which is like the cell liquid of a muscle cell.
Along each muscle fibre is a bunch of contractile units called sarcomeres, which are home to protein filaments known as actin and myosin as well as two other proteins called tropomysin and troponin which are bound to each other, but which we won’t go in to here. Actin and myosin can be considered to be like the small fibres on Velcro – they face, correspond with, and can stick to each other on opposing sides of a muscle fibre.
At rest myosin is attached to actin. To contract a muscle, ATP bonds to the myosin head and is hydrolysed into ADP and a free Phosphate group. This causes energy release which allows the myosin to reattach to the actin, a little further up and ‘pull’ the sarcomere a little closer together. When this happens all the way up a muscle, your muscle shortens and you do an awesome biceps curl to impress the ladies/gentlemen.
When you want to lower the weight again, you lengthen the muscle, but of course some of the sarcomeres are still working because if they weren’t, the bar would just drop and the muscle would lengthen very rapidly. This means that althought he muscle is lengthening, some parts of it are still contracting – this contraction during extension causes some of the actin and myosin proteins to break, resulting in what is known as microtrauma. Microtrauma leads to inflammation, inflammation leads to pain, that pain is called DOMS.
For completeness, there are other things which contribute to DOMS and it’s not 100% understood yet as a phenomenon, but that’s the main thing to remember.
One way which athletes have sought to mitigate this soreness, which can impair performance, strength, muscle suppleness and joint ROM is to take a recovery ice bath, or cold shower – a more ‘up to date’ method used by top sports teams is whole body cryotherapy, which involves sitting in an individual pod known as a cryosauna where the temperature drops well below -100C. This is so popular that it was used by the likes of Kobe Bryant in the last NBA season and just about every rugby player, ever, has taken an ice bath at one point or other.
Still, just because the pro’s do it and it’s popular, doesn’t make it a good idea.
One study from 2006 (5) found that after a training period, athletes who submerged trained bodyparts in cold water were three times less likely to experience significant training effects. The researchers theorised that icing the area prevented myofibril regeneration, hypertrophy and even expected changes in the localised blood supply.
In 2015 this study was replicated (6). Researchers found that after a training period, the group who cooled a trained area had significantly reduced hypertrophy and zero improvements in strength or arterial thickness, both of which WERE present in the non-cooled group . Researchers concluded that “Regular post-exercise cold application to muscles might attenuate muscular and vascular adaptations to resistance training.”
So is it really time to end the ice age?
(Again…I’m really sorry).
Well, probably, but as always there are caveats. My personal views, given the data, are:
- If injured, ice it for 2-3 10 minute rounds immediately as a means of reducing pain, then leave it alone. Compress, elevate and rehabilitate as soon as you are able.
- After training, DO NOT take an ice bath if the point of that training was a physical adaptation.
- If your main concern is not actual adaptation, but recovery, such as would be the case for a sportsman who has 2-3 games in a week, or a fighter who is in fight camp who needs to work on technique more than anything else, consider a semi-regular ice bath as it CAN alleviate pain which therefore allows you to train again, while baring in mind the possible repercussions.
- For general recovery purposes, ensure programming is sensible, your calories are high enough, you are consuming enough protein and you are sleeping well. After that, Recovery Spray might be a decent boost which doesn’t impact on adaptive mechanisms.
- Haiyan Lu, Danping Huang, Noah Saederup, Israel F. Charo, Richard M. Ransohoff, and Lan Zhou. Macrophages recruited via CCR2 produce insulin-like growth factor-1 to repair acute skeletal muscle injury FASEB J. doi:10.1096/fj.10-171579
- Kenwright et al. “Axial Movement and Tibial Fractures”. Journal of Bone and Joint Surgery, vol 73-B, No 4, July 1991
- Yamane et al. “Post-exercise leg and forearm flexor muscle cooling in humans attenuates endurance and resistance training effects on muscle performance and on circulatory adaptation”. Eur J Appl Physiol. 2006 Mar;96(5):572-80. Epub 2005 Dec 22.
- Yamane et al. “Does Regular Post-exercise Cold Application Attenuate Trained Muscle Adaptation?” Int J Sports Med. 2015 Jul;36(8):647-53. doi: 10.1055/s-0034-1398652. Epub 2015 Mar 11.