Video·3 min read·May 2026

The Science of Cold: Enhancing Recovery Through Contrast Therapy

Cold Therapy • 3 min read • Based on research by Giovanni Lombardi, Patrizia Lanteri, Simone Porcelli, Clara Mauri, Alessandra Colombini, Dalila Grasso, Viviana Zani, Felice Giulio Bonomi, Gianluca Melegati, Giuseppe Banfi (2013)

In our pursuit of optimal wellness, the connection between body and recovery is paramount. Many of us seek methods to enhance our resilience and vitality, often turning to various therapies. Among these, contrast therapy—combining heat and cold—has gained traction. But what does the science say about these practices, particularly when it comes to cold exposure through cryotherapy?

A recent study sheds light on this subject, focusing on professional rugby players and their hematological profiles during whole body cryotherapy. The findings offer valuable insights into how cold exposure might influence our recovery and overall health.

Understanding Cryotherapy and Its Effects

Cryotherapy involves exposing the body to extremely cold temperatures for short periods, typically in a specialized chamber. The study conducted by Lombardi et al. examined the effects of this therapy on 27 professional rugby players over a week, with two sessions each day.

Researchers collected blood samples before and after the treatment, revealing significant changes in the players' hematological profiles. Notably, they observed a decrease in erythrocytes, hematocrit, and hemoglobin levels. These changes may seem alarming, but they indicate a complex response of the body to cold exposure.

The Science Behind the Changes

When the body is exposed to cold, it undergoes a series of physiological responses. One key mechanism is the reduction in blood flow to extremities, which can lead to a temporary decrease in red blood cell counts and hemoglobin. In the study, serum transferrin and ferritin levels also decreased, while soluble transferrin receptor levels increased. This suggests that the body is adjusting its iron availability and utilization during recovery.

While these changes might sound concerning, they are part of the body's natural adaptation process. Cryotherapy can help reduce inflammation and pain, potentially speeding up recovery times. The temporary alterations in blood chemistry may pave the way for enhanced performance and resilience in the long run.

Practical Implications for Recovery Protocols

Understanding how cryotherapy affects hematological parameters is crucial for athletes and anyone engaged in rigorous physical activity. The study highlights the importance of tailoring recovery protocols to individual needs, especially when incorporating cold exposure.

For those looking to integrate contrast therapy into their routine, it is essential to approach it as a ritual rather than a one-time event. Regular exposure to cold, complemented by heat therapy, can promote equilibrium in the body’s systems, enhancing recovery and overall longevity.

Key Takeaways

Cryotherapy can modify blood chemistry, impacting recovery protocols for athletes and active individuals.
Understanding the body’s response to cold exposure can enhance resilience and performance over time.

Based on: Hematological Profile and Martial Status in Rugby Players during Whole Body Cryostimulation
Giovanni Lombardi, Patrizia Lanteri, Simone Porcelli, Clara Mauri, Alessandra Colombini, Dalila Grasso, Viviana Zani, Felice Giulio Bonomi, Gianluca Melegati, Giuseppe Banfi (2013). PLoS ONE

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Hematological Profile and Martial Status in Rugby Players during Whole

What This Paper Is Actually Saying

Lombardi and his team at the Galeazzi Orthopedic Institute in Milan ran a straightforward but important experiment: take 27 professional Italian rugby players, expose them to cryostimulation twice daily for seven consecutive days — that's 14 sessions total at negative 140 degrees Celsius — and measure what happens to their blood. The answer, in short, is quite a lot. Red blood cell counts dropped. Hemoglobin dropped. Iron storage markers dropped. The immature reticulocyte fraction — a measure of fresh red blood cell production from bone marrow — dropped substantially. The body was responding to this level of cold exposure in ways that looked, on paper, like the early stages of anemia.

But here's the nuance that the paper buries in its discussion and I think deserves center stage: these players were also training four hours a day at full intensity. Morning gym sessions, afternoon high-intensity field work. The cryotherapy wasn't happening in a clinical vacuum. It was being layered on top of a genuinely brutal physical load. So when we see those blood markers shift, we're watching the body negotiate two simultaneous stressors at once.

How This Compares to What Else We Know

This same research group published a similar study in 2008, but with half the dosing — once daily instead of twice, and five days instead of seven. The results were milder. Minor hemoglobin shifts, weak decreases in hemoglobinization. The authors noted then that duration and frequency probably mattered. This follow-up confirms it. Double the dose, and the signal gets louder.

A 2009 paper on whole body cryotherapy and inflammatory mediators found that WBC shifted immune markers — lymphocytes, monocytes — without dramatically altering red blood cell parameters. The contrast is instructive. At lower doses, the immune response is the dominant story. At higher doses, the hematological response starts to show up. Dose determines which system speaks first.

Cold is medicine. But like all medicine, the dose is not a minor detail — it's the whole story.

Where the Experts Are Still Working It Out

The paper can't fully resolve whether these blood changes come from hemodilution — plasma volume shifting after repeated temperature swings — or actual suppression of bone marrow activity, or some combination of both. The decrease in the immature reticulocyte fraction is the most provocative finding here, because that's a signal from the bone marrow itself. Something is slowing production at the source. Whether that recovers fully after treatment ends, we don't know, because the study only measured before and after the seven-day camp.

The Practical Recommendation

For anyone integrating cold therapy into a recovery protocol, this paper is a reminder that frequency and intensity are not interchangeable levers. A single plunge after training is a very different intervention than twice-daily cryochamber exposure during a week of elite-level training. The former is recovery support. The latter is a significant physiological load in its own right. If you're using cold therapeutically — which most of us are — the one-to-three times per week cadence supported by the broader literature is appropriate. Leave the twice-daily protocols to research settings with medical supervision.

The Detail Most People Miss

There's a passage in this paper about anti-doping implications that rarely gets discussed in wellness circles. The authors flag that aggressive WBC protocols can push blood chemistry outside the official limits set by sports federations — the same limits designed to detect blood doping. This means whole body cryotherapy, administered intensively enough, could theoretically trigger a false positive on an anti-doping screen. Or, more troublingly, it could be used to mask the markers of illicit blood manipulation. The paper isn't accusing anyone of anything. But it is saying: cold exposure at this intensity is biochemically powerful enough to show up in anti-doping surveillance. That's a useful reminder of just how seriously the body takes extreme temperature as a signal.

Hematological Profile and Martial Status in Rugby Players during Whole

The Science of Cold: Enhancing Recovery Through Contrast Therapy

Understanding Cryotherapy and Its Effects

The Science Behind the Changes

Practical Implications for Recovery Protocols

Key Takeaways

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