Cold therapy is a very popular treatment to enlighten the symptoms of an acute sport injury. It has been used for decades and is currently most often implemented as part of the RICE-method. This method has been taught for years now and consists of Rest, Ice, Compression and Elevation.
In recent years ice baths have also gained a lot of popularity among athletes and coaches as a way to speed up recovery after training, but does it? This article will give you further insight in the use of cold therapy. You will find out when cold therapy is useful and when it isn’t.
During a heavy workout you make muscle damage which needs to be repaired. Every repair in the body starts with local inflammation, this is a very complex biological process. The goal of the inflammation is to eliminate the source of damage (in the case of an infection), to clean up the damage (injured and necrotic cells) and to initiate tissue repair. All of this starts within minutes after the infection or injury/trauma en consists of a series of processes that act mostly simultaneously:
-An increase in local blood flow which causes the redness and temperature elevations.
-An increase in permeability to allow fluid and plasma proteins to the injured tissue.
-Attraction of multiple inflammation markers like bradykinin which will trigger pain sensors, and white blood cells which will start cleaning the damage.
Sounds good right? Without inflammation there is no recovery, but sometimes the inflammation overreacts and because this process is a bit aggressive it can cause damage as well. This is what we call secondary damage and is the result of an inflammatory phase which is too long in duration or just too aggressive. That’s why part of the recovery after training or injury needs to be focussed on lowering the inflammation. The body itself does this by production of anti-inflammatory cells and mediators roughly 30-60min after the initial trauma or infection. You yourself can support the healing process as well by limiting the inflammation. Well known of course are anti-inflammatory drugs, but cold therapy is also a way to dampen inflammation.
By cooling the injured body part, the blood vessels contract (vasoconstriction) resulting in decreased blood flow which causes a decrease in local redness, temperature and leakage of fluid. Besides that cold also stimulates the production of anti-inflammatory cells and inhibits the production of pro-inflammatory cells [1,5,6,12].
cold also stimulates the production of anti-inflammatory cells and inhibits the production of pro-inflammatory cells
Further effects of ice baths
Production of mitochondria.
The optimal body temperature is around 37 degrees Celsius, at that level it can work most efficiently so it will do everything within its power to maintain that. There are several ways in which the body reacts to cold temperatures, think of vasoconstriction (limiting blood flow) but also shivering. Shivering is nothing more than muscles contracting and relaxing causing it to burn energy which has a important byproduct: heat. For energy production you need cellular energy factories called mitochondria. Research  shows that repeated exposure to cold enhances production of certain hormones that stimulate synthesis of mitochondria. As the body adapts, it gets better at coping with low temperatures. Moreover, those extra mitochondria will boost your aerobic capacity and thus increase endurance.
Heart rate variability The Heart rate variability (HRV) is a way to monitor stress in the body. A full explanation of HRV is found HERE. As a result of training affecting the autonomic nervous system by increasing the activity of the sympathetic nervous system, the HRV lowers. After training the HRV will rise again due to higher activity of the parasympathetic nervous system, the body relaxes again. Exposure to cold increases this process, making it come back to pre-training levels more quickly [13,20,21,26]. A faster way to parasympathetic activity is giving the body a faster way to start recovery after training.
Practical effects on recovery
Ice baths looks like a useful recovery strategy, tested on team sports, single sports, endurance and sprint/strength training. Only bodybuilding could be an exception. Cold therapy was shown to have a negative result on muscle growth after hypertrophy training .
Quick summary of the results:
Less decrease in performance at 24,48 or 72 hours after a heavy training [1,2,10,11,13,14,15,17,19,23,24,26,27]
Less fatigue [10,18,15,25,27]
Less pain [9,18,25,15]
Lower inflammatory response and muscle damage [1,5,6,11,12,16,17]
When, how long and how cold?
Most studies use a protocol consisting of 10min in a ice bath with water of 10 degrees Celsius right after the training session or within a 30min timeframe.
- Effects of cold water immersion on the recovery of physical performance and muscle damage following a one-off soccer match
- whole body crytherapy for recovery after plyometric exercise.
- Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training
- Regular postexercise cooling enhances mitochondrial biogenesis through AMPK and p38 MAPK in human skeletal muscle
- Time-Course of Changes in Inflammatory Response after Whole-Body Cryotherapy Multi Exposures following Severe Exercise
- Five-Day Whole-Body Cryostimulation, Blood Inflammatory Markers, and Performance in High-Ranking Professional Tennis Players
- The effect of norepinephrine on endotoxin-mediated macrophage activation.
- Cold-water immersion and other forms of cryotherapy: physiological changes potentially affecting recovery from high-intensity exercise
- Cold water immersion recovery following intermittent-sprint exercise in the heat
- Effects of sports massage and intermittent cold-water immersion on recovery from matches by basketball players
- Cold-water immersion decreases cerebral oxygenation but improves recovery after intermittent-sprint exercise in the heat
- The effect of various cold-water immersion protocols on exercise-induced inflammatory response and functional recovery from high-intensity sprint exercise
- Effects of cold water immersion and active recovery on hemodynamics and recovery of muscle strength following resistance exercise
- Effect of cold water immersion on recovery and limb blood flow following high-intensity cycling
- Cold water immersion is most effective for recovery of repeat sprint ability and reducing fatigue post an Australian football game
- Effects of cold water immersion on the symptoms of exercise-induced muscle damage
- Influence of cold-water immersion on indices of muscle damage following prolonged intermittent shuttle running
- Effects of cold-water immersion on physical performance between successive matches in high-performance junior male soccer players
- Effect of cold water immersion on repeat cycling performance and thermoregulation in the heat
- The effects of cold water immersion with different dosages (duration and temperature variations) on heart rate variability post-exercise recovery: A randomized controlled trial
- Effect of cold water immersion on postexercise parasympathetic reactivation
- Motor and Sensory Nerve Conduction Are Affected Differently by Ice Pack, Ice Massage, and Cold Water Immersion
- Effect of a 5-min cold-water immersion recovery on exercise performance in the heat
- The Effect of Hot or Cold Water Immersion on Isometric Strength Training.
- Effect of post-match cold-water immersion on subsequent match running performance in junior soccer players during tournament play
- Consecutive days of cold water immersion: effects on cycling performance and heart rate variability
- Effect of Immediate and Delayed Cold Water Immersion After a High Intensity Exercise Session on Subsequent Run Performance