The longstanding fix to every ache, pain, or injury associated with sport is to 'ice it.' However, research conducted in the past decade suggests better options for injuries and recovery. Sports medicine professionals are supposed to use evidence-based practices, but despite the swaths of anti-icing research, people still ice. Old habits die hard. The principle theory of R.I.C.E. (Rest, Ice, Compression, Elevation) has been so soundly debunked in research that the physician who invented the phrase has even retracted his stance.
It is important to understand the difference between cold water immersion and cold application (icing). In this blog, I’ll help to draw the fine line between them. Cold application to an injury site provides little more than an anesthetic effect, numbing the superficial skin layers to reduce the sensation of pain. Using the research, cold application’s impact on tissue healing and inflammation is inconsistent at best, unsupported at worst. Have you seen an MLB player slap ice on their pitching shoulder after a game for recovery? I have too. With or without an acute injury, there are better options for recovery.
Throw Out Rest and Ice, Keep Elevation and Compression
One theory about cold application from the late 1980s suggests that ice delays the function of the lymphatic system, however, the lymphatic system is important for healing. We can’t speak definitively about ice delaying healing but we do know one thing: ice certainly does not expedite healing. Early phases of inflammation are crucial to tissue repair. Inflammation is the first step in the process of healing. Repair and remodeling follow close behind. Chronic inflammation is a burden, like that ankle sprain, still ‘fat’ after two weeks. It is painful; it is stiff; it is hindering your performance. For several decades, we’ve had the common belief that the body overworks after injury and that is the source of the excessive inflammation - which must be reduced with icing. However, chronic inflammation is actually a reaction to problems that arise from lack of engaging in more productive rehabilitation methods, such as increasing range of motion. The best way to reduce chronic inflammation is practice pain-free rehabilitation and strengthening - so you might as well throw out the ‘rest’ part, too. An attempt to ‘restrict’ inflammation via ice and rest is ineffective. Replace this old method with elevation and compression; those approaches will attenuate edema (swelling) by shuttling the fluid into the lymphatic system. The lymphatic system is responsible for ridding our bodies of excess liquid waste. Some other successful methods are effiage massage (manually massaging swelling, pushing in the direction of larger muscle groups which can then aid the transition to the lymphatic system) or a KinesoTape application that aids in re-routing swelling, away from pooling in extremities.
Research for Tissue Healing Mechanisms
Randomized-control trials are the highest quality of research and yield the most reliable outcomes. In randomized-control trials, participants are blind to what group they’re in, experimental or control. The experimental group receives the treatment studied, and the control group does not, usually receiving a placebo or no treatment at all. This is why drug trials are successful - participants do not know what drug they are taking (or a placebo), and this helps eliminate participant bias. When it comes to researching recovery strategies, participants know if they are in a cold tub or not. This, of course, can cause bias in the results, so recovery strategies are difficult to research. The consequence means leafing through dozens of studies with many questions still unanswered. At RXSR our main concern is recovery after training, with or without any acute injury, and we aspire to provide the services most favored by research. Research does suggest cold water immersion to aid in recovery. High intensity, high volume training creates muscle damage and depletes energy stores such as glycogen. ‘Recovering’ from this requires athletes to expedite the processes for muscle regeneration and/or energy replenishment. Look to our past blogs about metabolic replenishment; here we will speak to tissue healing.
Studying metabolic reactions after resistance exercise, for instance, can lead to insight on tissue healing. With this, we can adopt strategies to mimic natural healing affects. Muscle damage after activity is measured by the rise of serum creatine kinase (CK) levels in the bloodstream. CK in the bloodstream causes an inflammatory response and signals the need for insulin-like growth factor-1 (IGF-1). IGF-1 is a protein that is crucial for regeneration of damaged skeletal tissue. Thus, the inflammatory response is good for muscle repair. Why would we want to restrict that process?
To encourage this process, we suggest alternating the vasoconstricting effects of cold whirlpool with its opposite, vasodilation of hot whirlpool; that alternation between vasoconstriction and vasodilation is a method known as contrast therapy. Contrast water therapy has received considerable attention as an alternative to simply icing. However, contrast therapy has not been adopted across the board as the go-to recovery method. A combination of vasoconstriction and vasodilation increases blood flow to promote those necessary inflammatory responses. Extended cold exposure (>15 minutes) without warming can impair muscle function, possibly by altering neuromuscular properties during muscle contractions (Roberts, 2015). Thus, it is advised to reduce time spent exclusively in a cold tub, about 5 minutes. Using short durations of cold and heat can avoid impairment to muscle function. These effects could have important implication for athletes who use cold water immersion to recovery quickly between training sessions or competitive events.
Cold Water Immersion Impact on Performance
Research has found that water immersion reduces perception of muscle fatigue and pain in participants compared to control groups. This phenomenon has physical and psychological explanations. A randomized-controlled study examined basketball players who endured three, high intensity 90-minute training sessions. Perception of muscle pain and a jumping task were measured after water immersion therapy and after no therapy (control). Water immersion groups had reduced perceived pain both 24 and 48 hours after activity and an increase percent change with jumping task in comparison with the control group (Urena, 2015).
Cold water immersion deserves more investigation, but one theory around its effect on performance involves lactic acid. Lactic acid is not responsible for delayed-onset muscle soreness (DOMS) but is responsible for the sensation of muscle fatigue and pain right before termination of activity [See "Science of Recovery" here]. This sensation occurs when lactic acid stimulates group III/IV afferents in skeletal muscle. When stimulated, group III/IV afferents limit the body via a diminishing effect on the output of muscle motor neurons, which then decreases voluntary muscle contractions (Roberts, 2015). There is evidence that cold exposure inhibits the activity of group III/IV afferents and reduces accumulation of lactic acid during muscle contraction. By reducing lactic acid accumulation in muscle, cold water immersion may have minimized the perceptions of fatigue and pain, thus allowing greater force production. This mechanism can become important for athletes readiness to perform and compete. Additionally, a study by Xu and Brennan measured afferent sensitivity with injuries and suggests we are more sensitive to afferents if the muscle is injured (Xu, 2010). Therefore, cold water immersion can be crucial recovery when trying to delay fatigue in an injured muscle, such as with a hamstring strain.
Evidence-Based Recovery Strategy Recommendations From RXSR
This was a lot of information. The question is, “If I don’t need to be icing, what should I do?” At RX Sports Recovery we host dozens of athletes practicing different recovery strategies. We’ll use an ultra-marathon runner with a hamstring issue as our example athlete. Here is a brief list of evidence-based strategies that are better than applying ice:
Proper Rehabilitation: A good place to start is to find why your hamstring is chronically hurt. If you’ve received appropriate medical attention to rule out anything requiring complete rest, then the next step is to learn corrective exercises you can perform yourself. I use something called NeuroKinetic Therapy to locate compensation patterns in the body. A muscle that is chronically tight is usually working too hard or not working enough. About 80% of the time, hamstrings work too hard for its synergist, gluteus maximus or its functional opposite, rectus femoris. These are compensation patterns worth discovering. My first suggestion is addressing the cause (the compensation) instead of treating its symptoms. RXSR can help with that and get you started on a recovery treatment plan.
Cross-Train: Active recovery is something I did not touch on this blog, but stimulating circulation with activity is gold-standard recovery. You can accomplish this by cycling, swimming, water jogging, or rowing at a low intensity; these are activities that are different from your primary sport to stress different muscles and energy metabolism. At RX, we frequently use CompexUSA muscle stimulation on the ‘active recovery’ setting to mimic this concept. With Compex, the muscle stimulation can be more targeted on that nagging hamstring. A great suggestion for active recovery is to road bike along some of the great paths near RXSR [Examples here] and stop in to utilize our recovery services afterward for maximum benefits.
Compression, Elevation, and Contrast to Promote Blood Flow: This can be accomplished by the NormaTec units, a research-backed method to increasing circulation to extremities. A single 30 to 40 minute session can stimulate lymphatic activity. Contrast therapy is also a great choice for your recovery day thanks to the tissue healing and performance enhancing benefits explained above. Based on the precise guidelines for water immersion use, we suggest two to three cycles of 5 minutes each in our hot and cold tubs.
Amann, M. et al. Automatic responses to exercise: Group III/IV muscle afferents and fatigue Autonomic Neuroscience. Volume 188. Mar 2015. 19-23.
Roberts, LA. Effects of cold water immersion and active recovery on hemodynamics and recovery of muscle strength following resistance exercise. Am J Physiol Regul Integr Comp Physiol. Aug 2015. 309(4). 389-98.
Urena, Braulio, et. al. The use of continuous vs. intermittent cold water immersion as a recovery method in basketball players after training: a randomized controlled trial, Mar 2017. 134-139. The Physician and Sportsmedicine. Volume 25.
Xu, J., Gu, He., Brennan, T. Increased sensitivity of group III and group IV afferents from incised muscle in vitro. Pain Journal. Dec 2010. 151(3). 744-755.