Cold Water Immersion for Athlete Recovery – Is it as good as we think?

By Declan Chapman

 

In recent years an emphasis has been placed on optimising recovery (restoration of physiological and psychological states to a pre-fatigued baseline) in athletes. The current theory is that suboptimal recovery leads to compounding fatigue and poor-quality performance due to the body’s inability to return to physiological and psychological baseline prior to exertion. Exercise science research has focused on investigating different modalities designed to accelerate recovery. Cold Water Immersion (CWI) is one of these modalities which has been adopted by many athletes as the foundation of their recovery regime. Given the current trend in favour of CWI as a recovery modality, I felt that clarification of its proposed benefits are warranted.

 

Is CWI as good as we think, or is it just an exciting new trend?

 

Proposed Mechanisms in favour of CWI for Athlete Recovery

Reduced Muscle Soreness

• Vasoconstriction (narrowing of blood vessels) occurs when we are exposed to cold temperatures. During CWI the vasoconstrictive effect reduces blood flow to our muscles and therefore reduces the inflammatory response. 

• During CWI we also observe a reduction in nerve conduction velocity. This generally leads to a reduced pain perception and sensitivity in the effected muscles.

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​Improved Muscle Function

• It is hypothesised that by reducing the temperature of our body we can mitigate the effects of exercise-induced hyperthermia. Lower muscle temperatures have been shown to reduce metabolic rate and oxygen demand. This allows our body to conserve energy and facilitate a more efficient cellular repair.

• Lower temperatures have also been shown to improve muscle contractility and coordination by reducing motor neuron excitability by partially inhibiting synaptic transmission. 

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Mitigation of the Inflammatory Response

• As mentioned, the vasoconstrictive effect of cold temperatures has been shown to reduce our inflammatory response. This is achieved by inhibiting the production and release of pro-inflammatory cytokines (interleukin-6) and tumour necrosis factor-alpha (TNF-alpha), while activating the production and release of anti-inflammatory cytokines (interleukin-10).

• The blunting of this acute inflammatory cascade has been shown to minimise tissue damage and swelling.

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​Alleviation of Fatigue

• During CWI our sympathetic nervous system is activated. Our body releases catecholamines such as adrenaline which increases heart rate. We also observe a reduction in the accumulation of lactate and hydrogen in the body. The attenuation of lactate build-up prolongs endurance and delays the onset of muscular fatigue.

• The psychological effect of CWI should also be mentioned. Many athletes believe that CWI will improve recovery – thus they feel better following it.

 

These mechanisms have been theorised to improve athlete recovery by promoting tissue repair, enhancing physiological adaptations, and mitigating exercise induced hyperthermia. However, the exact mechanisms which underly the effect of CWI may vary based on individual factors, exercise intensity, and environmental conditions.

 

Whilst this all sounds very good – there is an opposing viewpoint that suggests potential drawbacks and limitations for the use of CWI in athlete recovery.

 

Proposed Mechanisms against the use of CWI for Athlete Recovery

Impaired Adaptations:

• ​Frequent and prolonged use of CWI has been shown to interfere with the adaptive response we observe with exercise. This includes the beneficial adaptions to metabolic pathways and muscle tissue repair. This interference has been hypothesised to attenuate any long term benefits of training and overall performance improvements.

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​​Inhibition of the Inflammatory Response:

• ​Whilst CWI has shown to reduce acute inflammation, many studies have suggested that it impedes on the important adaptive inflammatory response which we require for optimal tissue remodelling and repair. The blunting of the inflammatory cascade can hinder the physiological process needed for long-term adaptation and recovery.

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​Vasoconstriction

• As previously mentioned, CWI induces vasoconstriction, reducing the blood flow and nutrient delivery to damaged muscle. This reduced blood flow has been shown to slow the removal of metabolic by-products and delay the initiation of repair mechanisms, prolonging the time it takes to recover (essentially prolonging athlete recovery rather than improve it).

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Individual Variability and Psychological Discomfort

• Every individual has a different response to CWI. Factors such as body composition, fitness level, thermoregulatory capacity, and exercise intensity can all influence the effectives of CWI.

• Many athletes do not enjoy CWI as it creates a psychological discomfort. The negative psychological response to CWI may undermine its utility, create negative physiological effects, and compromise compliance and adherence to recovery protocols in general.

 

To summarise, CWI holds promise as a modality for athlete recovery. However, the effectiveness and suitability of its use for each individual should be considered. Whilst CWI is the trend in social media at the moment, further research is warranted to confirm its true utility in an athlete environment.

 

In terms of optimal protocols there has been wide variability. My impression from reading the literature is that the ideal temperature for CWI sits between 8-12oC. Anything warmer does not get the full vasoconstrictive effect which many athletes’ desire. Whilst anything colder creates a hypothermic effect and potentially damaging physiological responses. For the best response it has been suggested to complete 10-20 minutes of total CWI in intervals of 3-5 minutes.