When you get into an ice bath, your heart does some interesting things, as it is an abnormal shock to the body. But what happens to the body, and is repeated cold water therapy a good or bad thing?
Plunging into an ice bath puts stress on the heart, but is generally considered safe for healthy people. Cold water therapy is a stressor that may provide physical and mental benefits, but the shock is risky for those with heart conditions.
In this article, we will look at what cold therapy does to the heart and weigh the potential benefits and risks.
How do Ice Baths Affect the Heart?
The heart rate initially increases during cold water immersion, the output of the heart is then increased, proving that cold therapy does put some stress on the heart. Though there is a good amount of research on the effects of cold water immersion, more is needed to see exactly how it could impact heart health long term.
In some recent research, the stresses and supposed negative effects of cold water immersion on the heart were measured up to 180 min after with 16 participants. 15-minute immersion in cold water 50°F (10°C) showed that while participants’ positive feelings remained the same, their negative feelings and cortisol levels significantly decreased three hours after the immersion [1].
Scientists found that the size and speed of blood flow in the arm’s main artery changed. This meant that the arm’s blood vessels didn’t open as wide as usual during and just after being in the cold water. Also, 30 minutes after coming out of the cold water, the stress on these blood vessels decreased.
This research suggests that while acute cold water immersion has a minor impact on shear stress patterns in the body, it may offer mental health benefits and lower stress hormone levels.
A study in 2014 explored how being in water affects heart responses and blood flow in the brain in 9 healthy young men [2]. The researchers thought that if the water level reached the heart’s right atrium, it would increase blood flow to the brain.
They found that when the men were in the cold water, their average blood pressure, heart output, and carbon dioxide levels at the end of a breath increased. Blood flow speeds in the middle and back parts of the brain also went up during water immersion and then went back to normal after the men got out. This research showed that being in water, at least up to the chest, causes the heart to improve blood flow in the brain.
In another study measuring the cold shock response of cold water immersion [3], 8 healthy males immersed themselves occasionally for 14 months. Participants showed a significant decrease in how fast they breathed, how much air they inhaled per minute, and their heart rate during the first 30 seconds of immersion by the fifth day, compared to the first day.
Even after seven months, these reductions in their breathing and heart rate responses to cold water were still noticeable, and after 14 months, while their heart rate response remained low, their breathing rate and air intake started to return to normal. This study concluded that regularly immersing in cold water can reduce the body’s initial shock response to cold for up to 7-14 months, and even if immersions become less frequent, the intensity of the cold shock response remains decreased.
Benefits of Ice Baths for Heart Health
1. Reduced Mental Stress
An ice bath can make you feel better and less tired, which is good for your heart because it reduces stress. Studies using special brain scans have found that being in cold water might change how our brains handle emotions, helping to lower the stress on our hearts. This research is still ongoing, but shows proof of the reliable increase in connectivity after immersion [4].
Cold-water immersion, along with other mind-body exercises, has also been linked to reduced stress and enhanced well-being [5]. This stress reduction can indirectly benefit heart health, as stress is a known contributor to cardiovascular issues. The relaxation and mental clarity gained from an ice bath might help alleviate stress, which in turn, could have a positive effect on heart health.
2. Reduced Inflammation
Cold therapy, including an ice bath or cold plunge, has shown potential benefits for heart health by reducing inflammation and the heart’s workload. Studies have found that in animal models, this therapy helps in managing inflammation and aids recovery after muscle injuries.
Additionally, researchers have stated that the physiological effects of cold therapy can cause reduced pain, decreased blood flow, lessened edema, inflammation reduction, muscle spasm relief, and decreased metabolic demand [6]. These benefits are important because inflammation can strain the heart, and managing it effectively is beneficial for heart health.
3. Boosted Metabolism
Research on cold water immersion and its impact on metabolism could show signs of potential heart health benefits. For instance, a study [7] reported that short-term cold acclimation significantly improved insulin sensitivity in patients with type 2 diabetes.
Another study showed that cold water therapy gave participants significant boosts in metabolic rates, up to 350% [8]. The findings from both these studies suggest that exposure to cold temperatures can increase the body’s efficiency in using insulin, which is vital for regulating blood sugar levels and overall metabolic health.
4. Better Sleep Quality
Cold therapy has been shown to positively affect sleep quality, which can be crucial for heart health. A study involving well-trained male endurance runners investigated the impact of CWI on sleep architecture and recovery. The participants underwent whole-body or partial-body CWI after high-intensity exercise.
The study showed that whole-body immersion reduced arousal and limb movement and enhanced slow-wave sleep early in the night [9]. This slow-wave sleep is known for its restorative effects, including the reduction of heart rate and blood pressure. Good sleep quality helps in regulating stress hormones and maintaining a healthy balance of the nervous system, further contributing to cardiovascular well-being.
5. Improved Circulation
Improved circulation is a key potential benefit of ice baths for heart health. A study specifically investigating the effect of cold water immersion on limb blood flow during cycling performance provides insight into this [10]. The study found that cold water immersion influenced blood flow, which is critical for efficient oxygen and nutrient delivery throughout the body and for the removal of waste products.
Improved circulation, from the vasoconstrictive and vasodilative responses to cold exposure, could enhance overall cardiovascular function. This enhanced blood flow is not just beneficial for athletes in recovery but could also be advantageous for heart health in general. This can be particularly beneficial in helping conditions like hypertension, a common risk factor for heart disease.
Are Ice Baths Bad for Your Heart?
While ice baths might have potential health benefits, they also pose certain risks, especially for people with heart conditions.
1. General Cardiac Stress
One significant risk is sudden cardiac stress. The shock of the cold can put immediate stress on the heart, which is particularly dangerous for those with underlying heart issues. Another concern is the risk of hypertension. People with high blood pressure might experience a harmful spike in blood pressure due to cold exposure.
Unplanned stressors, like unexpectedly falling into cold water, are more dangerous and can be triggers for sudden cardiac death. The effects of planned stressors like ice baths can vary widely between individuals. Therefore, it’s important for people, especially those with heart conditions, to use ice baths cautiously and under medical advice to mitigate potential risks.
2. Tachycardia and Arrhythmias
When you jump into cold water, your heart reacts in two opposite ways, first speeding up and then slowing. The initial reaction speeds up your heart to induce Tachycardia, which can be a normal reaction to a stressor. However, the suddenness of this increased heart rate may be a risk.
This can potentially cause heart arrhythmias or irregular heartbeats. Even just holding your breath and then letting it go in cold water can cause these problems. Some people might be more likely to have these issues because of how their heart reacts to fast changes in their heartbeat.
3. Increased Blood Pressure
Taking an ice bath can cause a temporary increase in blood pressure because the constriction of blood vessels increases the resistance against which the heart must pump blood. While this effect is temporary and usually not a concern for healthy individuals, it could be problematic for certain groups of people.
For individuals with pre-existing high blood pressure (hypertension) or cardiovascular diseases, the sudden increase in blood pressure from an ice bath could pose a risk. The added stress on the cardiovascular system in these cases might lead to complications, especially if the heart is already working harder than normal to circulate blood.
How to Safely Start Taking Ice Baths
Temperature of the Water
The temperature of the water in an ice bath is a crucial factor. For beginners, it’s advisable to start with a slightly warmer temperature, around 55°F to 60°F, and gradually acclimate to colder temperatures. This gradual adaptation can help minimize the shock to the system, reducing the risk of adverse cardiac responses.
For an in-depth look into possible different temperatures see our guide on Cold Plunge Temperatures.
Duration of Cold Therapy
The duration of exposure in an ice bath should be carefully managed. For those new to ice baths, starting with short sessions of about 5-10 minutes is recommended. As your body becomes accustomed to the cold, you can gradually increase the duration, but it should not exceed 15-20 minutes. Longer exposures can increase the risks of hypothermia and other negative effects, especially in individuals not accustomed to extreme cold.
Final Thoughts
When beginning ice bath therapy, it’s important to consider any existing health conditions, particularly heart-related issues. Consulting with a healthcare professional before starting is advisable to ensure it is safe for you. Additionally, it’s essential to ease into the practice gradually, starting with less extreme temperatures and shorter durations, and paying attention to how your body reacts.
For those interested in exploring cold water therapy further and looking for equipment or ideas to enhance their experience, be sure to visit our cold water therapy store! We often offer a range of equipment, from ice bath tubs to cold plunges to accessories, along with guidance and ideas to help you optimize your cold water therapy sessions safely and effectively.
In conclusion, while ice baths have potential benefits for heart health, including reduced stress, inflammation, and improved circulation, they must be approached with caution. By carefully managing the water temperature and duration of immersion, and considering individual health circumstances, one can enjoy the benefits of cold water therapy while minimizing the risks.
References
- Reed, Emma L et al. “Cardiovascular and mood responses to an acute bout of cold water immersion.” Journal of thermal biology, vol. 118 103727. 14 Oct. 2023, doi:10.1016/j.jtherbio.2023.103727
- Carter, Howard H et al. “Cardiovascular responses to water immersion in humans: impact on cerebral perfusion.” American journal of physiology. Regulatory, integrative and comparative physiology vol. 306,9 (2014): R636-40. doi:10.1152/ajpregu.00516.2013
- Tipton, M J et al. “Permanence of the habituation of the initial responses to cold-water immersion in humans.” European journal of applied physiology vol. 83,1 (2000): 17-21. doi:10.1007/s004210000255
- Yankouskaya, Ala et al. “The Effects of Whole-body Cold-water Immersion on Brain Connectivity Related to the Affective State in Adults Using fMRI: A Protocol of a Pre-post Experimental Design.” Bio-protocol vol. 13,17 e4794. 5 Sep. 2023, doi:10.21769/BioProtoc.4794
- Faid, Troy et al. “Breathing Exercises, Cold-Water Immersion, and Meditation: Mind-Body Practices Lead to Reduced Stress and Enhanced Well-Being.” Advances in mind-body medicine vol. 36,3 (2022): 12-20.
- Malanga, Gerard A et al. “Mechanisms and efficacy of heat and cold therapies for musculoskeletal injury.” Postgraduate medicine vol. 127,1 (2015): 57-65. doi:10.1080/00325481.2015.992719
- Hanssen, Mark J W et al. “Short-term cold acclimation improves insulin sensitivity in patients with type 2 diabetes mellitus.” Nature medicine vol. 21,8 (2015): 863-5. doi:10.1038/nm.3891
- Srámek, P et al. “Human physiological responses to immersion into water of different temperatures.” European journal of applied physiology vol. 81,5 (2000): 436-42. doi:10.1007/s004210050065
- Chauvineau, Maxime et al. “Effect of the Depth of Cold Water Immersion on Sleep Architecture and Recovery Among Well-Trained Male Endurance Runners.” Frontiers in sports and active living vol. 3 659990. 31 Mar. 2021, doi:10.3389/fspor.2021.659990
- Vaile, J et al. “Effect of cold water immersion on repeated cycling performance and limb blood flow.” British journal of sports medicine vol. 45,10 (2011): 825-9. doi:10.1136/bjsm.2009.067272
