To ice or not to Ice?

In the dynamic world of sports science, cryotherapy has emerged as a ubiquitous tool in injury treatment and exercise recovery. This article aims to thoroughly investigate a recent narrative review (Kwiecien, 2021), providing an in-depth analysis of the current evidence surrounding various cryotherapy modalities.

Kwiecien, S.Y. and McHugh, M.P., 2021. The cold truth: the role of cryotherapy in the treatment of injury and recovery from exercise. European journal of applied physiology, 121(8), pp.2125-2142.

Debates Among Clinicians

Cryotherapy, defined as the reduction of tissue temperature through the withdrawal of heat from the body, has roots in centuries-old practices of injury treatment. The pathways to injury-induced structural damage involve both direct insults, such as blunt force trauma, and indirect pathways like mechanical stress and metabolic stress during exercise.

Understanding the natural course of catabolic events in muscle fibers, the review emphasizes the secondary stage, where cryotherapy might play a role in diminishing the proliferation of initial damage. Despite the longstanding tradition of applying ice, compression, and elevation (ICE), evidence supporting its use is limited, leading to ongoing debates among clinicians about best practices following injury.

The lack of consistent and unanimous evidence regarding the molecular response to cryotherapy has resulted in controversy over its efficacy in both injury treatment and exercise recovery.

Key points to consider

1.???? Effects on Metabolism and Inflammation

There is a pervasive belief that cryotherapy reduces the metabolic rate and inflammation by lowering temperature and blood flow at the injury site. However, evidence supporting this in human studies is limited, and caution is warranted when translating findings from animal models to human applications.

The review emphasises the need for recognition of the differences in metabolic properties between rodent and human muscles, questioning the direct applicability of animal study outcomes. The ability of cryotherapy to reduce muscle metabolism in humans remains inconclusive.

To address these uncertainties, ongoing research is necessary, involving well-designed human studies that account for the intricacies of metabolic responses and inflammation in various clinical scenarios.

2.???? Tissue Temperature and Cryotherapy Mechanisms

Traditionally, cryotherapy mechanisms were believed to be dependent on the cold-induced vascular response, reducing muscle blood flow and, consequently, metabolism. However, recent insights highlight that cryotherapy's effectiveness is primarily dependent on its ability to reduce muscle temperature, not blood flow.

Understanding the variable changes in tissue temperature across different layers, including skin, fat, and deep muscle, is crucial. The article emphasises that reducing skin temperature without affecting deep muscle temperature may lead to ineffective recovery and potential cold-related injuries.

The nuanced discussion prompts a call for more precise cryotherapy protocols, considering factors such as application duration, target tissue depth, and individual variability in thermal responses.

3.???? Cryotherapy Modalities and Their Effects

Various cryotherapy modalities, such as ice application, whole-body cryotherapy, and cold-water immersion, are analysed for their efficacy in injury treatment and exercise recovery. While ice remains a mainstay for immediate pain relieving effects, evidence supporting its use for accelerating recovery is uncertain.

Whole-body cryotherapy and cold-water immersion show promise in subjective recovery and soreness reduction following exercise. However, the variability in immersion temperature and duration affects the outcomes, and the review calls for a nuanced approach.

Researchers and practitioners should collaborate to establish standardized protocols for different cryotherapy modalities, considering the specific context of application and individual athlete characteristics.

4.???? Detrimental Effects of Cryotherapy

The article addresses the growing trend in the literature recommending against routine cryotherapy, particularly ice application, due to concerns about delaying the natural healing response. It explores evidence suggesting detrimental effects on muscle mass, strength gains, and muscle protein synthesis rates, especially with regular use.

The nuanced discussion highlights that while chronic use of cold-water immersion may attenuate recovery from traditional resistance training, acute cryotherapy does not compromise the protective adaptation after repeated eccentric exercise bouts.

Practitioners and athletes must weigh the potential benefits and risks of cryotherapy, considering the specific phase of training, the nature of the exercise, and individual recovery goals.

The take away

In conclusion, the article advocates for a nuanced understanding of cryotherapy's role in injury treatment and exercise recovery. Traditional modalities like ice, while providing pain relief, should be carefully considered, recognising the limited evidence supporting their use for accelerating recovery. The primary goal of cryotherapy is to maintain a reduction in intramuscular temperature in the immediate stages following injury or exercise to hinder secondary damage proliferation.

Recent studies suggesting no adverse events pave the way for prolonged cooling with phase change material (PCM) as a safe alternative to traditional cryotherapy. The article recommends against routine cryotherapy during normal training to avoid hindering training adaptations but advocates its use when natural recovery time is inadequate, prioritizing recovery and avoiding catabolism.

Clinical Use Recommendations

1.???? Immediate Application: Apply cryotherapy as soon as possible after injury or exercise to reduce inflammation and manage pain effectively.

2.???? Time of Application: Consider 15-20 minutes of cold exposure 2/3 times a day post-injury for potential benefits in pain levels and recovery time.

3.???? Full Body Cold Immersion: Avoid immediate post-exercise full-body cold immersion, as it may blunt hormonal and cellular responses to mechanical load.

4.???? Cold Immersion for Reducing Muscle Soreness: Recommended for in-season athletes preparing for a competition/match 24/72 hours away to alleviate soreness. However, it is not recommended if seeking to improve performance, as mentioned above.