Recovery: The Benefits of Cold-Water Immersion for Runners

During particularly intense periods of training, increased loads of physiological and psychological stress can have a major impact on your performance. Under these conditions, it is crucial to allow for ample recovery time in order to minimize fatigue and maintain optimal performance (1).

Our growing interest recovery has given rise to new techniques, such as: massage therapy, self-massage, electrical muscle stimulation, whole body vibration, compression garments, hyperbaric oxygen therapy, cryotherapy, and contrast bath therapy.

Water immersion has become the most widely used recovery method by high-performance athletes (2,3). There are three recovery approaches when it comes to water immersion: cold water, hot water, or contrast (hot/cold).

It is generally believed that immersion therapy can:

• Reduce swelling
• Reduce painful sensations in association with muscle pain
• Reduce the feeling of fatigue
• Regulate localized blood flow
• Regulate localized tissue and internal temperature
• Regulate heart rate
• Reduce muscle spasms
• Reduce inflammation
• Reduce muscle damage
• Improve range of motion

While research may support some of these claims, others seem to have inadequate scientific evidence behind them.

Cold-water immersion

Cold-water immersion, a form of cryotherapy, is a recovery method that involves immersing the body in cold water (≤15˚C/59°F) immediately after a workout as a measure to enhance the healing process (2, 3, 4).

Does cold-water immersion really aid in recovery?

Training can inflict damage on the musculoskeletal, nervous, and metabolic systems. Scientific studies have tested the effectiveness of cold water immersion therapy by measuring changes in both subjective and objective factors.

Subjective factors

• Delayed onset muscle soreness (DOMS) (3)
• Borg Rating of Perceived Exertion (RPE) (3)

Objective factors

• Creatine kinase (CK) (3)
• Blood lactate concentration (3)
• Interleukins (IL) (3)
• C-reactive protein (CRP) (3)

Scientific studies have shown that cold-water immersion significantly reduces the effects of sore muscles and perceived exertion. A recent meta-analysis concluded that cold-water immersion is an effective technique for:

• Reducing the symptoms of muscle soreness 24 hours, 48 hours and 96 hours after exercise (3,2).
• Reducing the perceived exertion 24 hours after exercise (3,2).

However, the objective factors post-exercise are less apparent and therefore question the mechanisms responsible for the subjective results (3).

How does cold-water immersion aid in recovery?

Despite extensive research into cold-water immersion therapy, the key mechanisms for improving recovery are still not fully understood. Still, we can entertain the following hypotheses:

• Vasoconstriction (narrowing of the blood vessels)
• Analgesic effect of cold water
• Decreased inflammatory pathways
• Placebo effect
• Hydrostatic pressure

Practical application

Temperature

Although there is currently no consensus on the temperature needed for optimal results, research protocol generally looks at between 8 to 15 °C (50 to 59 °F) with an average temperature of 11 °C (52 °F) (4). Therefore, it is advisable to opt for a temperature of around 11 °C (52 °F).

Duration

Researchers suggest an optimal immersion time between 11 and 15 minutes. And to encourage the occurrence of blood plasma fractionation (movement of the interstitial/intravascular fluid) it is suggested that one remains immersed for at least 10 minutes to optimize the full recovery effects. Although, positive effects of cold-water immersion have been reported for durations between 1 and 15 minutes (2,3), so it may still be beneficial to opt for shorter immersion sessions.

Depth of immersion

As hydrostatic pressure can be an important factor in recovery (9), we can suppose that the deeper the athlete is immersed in water, the greater the potential for his or her recovery. Moreover, since the purpose of immersion is to move fluids from the peripheral to the thoracic region, and because the act of immersion imposes an inward and upward force on the body, it is advised to stay upright during the process. However, this technique may vary depending on the sport or activity; that is, the dominant-upper-limb sports’ enthusiasts may see an additional advantage to being immersed in the supine position.

Conclusion

Although cold-water immersion is a popular recovery technique, there is still much for us to learn in terms of which protocols to use to achieve optimal results. There are still disagreements among researchers regarding ideal temperature for maximum recovery, which includes our expanding knowledge of thermoneutral water temperatures, which may be even more effective than cold water. In summary, vertical immersion of the entire body in cold (≤15˚C / 59˚F) to thermoneutral (34-35˚C/93-95 °F) temperatures for a duration of 11 to 15 minutes following exercise appears to have a positive effect on recovery.

Written by:
Guillaume Boitel – Doctor in Physiology, Bio-mechanics, and Sports Sciences