Can Nurosym neuromodulation be a safe and enjoyable alternative to ice baths (Cold Water Immersion)?


Dr Elisabetta Burchi, MD, MBA 
Clinical Psychiatrist 
Translational Research Lead at Parasym


Editor: Dr. Greta Dalle Luche, PhD, Head of R&D

The use of ice baths is becoming increasingly popular both for general mental health and athletic recovery, this is primarily due to the effects on the autonomic nervous system and ability to reduce inflammation.


Now, some elite athletes and even high-functioning executives are using another tool - the Nurosym™ neuromodulation wearable, to get these benefits, which is like an ice bath, but enjoyable. 


This new approach increases the activity of the calming ‘rest and digest’ side of the nervous system by up to 50% in just 5 minutes, which can be a potent stress reliever ​[1]. By contrast, the ice bath has an initial increase in stress (fight or flight), followed by a recovery and minor increase (in parasympathetic activity) on the same scale [​2] .


Nurosym vs Cold Water Immersion (CWI)









































Autonomic Nervous System Vagal Tone


Nurosym neuromodulation demonstrated a 50% increase in Parasympathetic activity after just 5 minutes (as measured by High-frequency Heart Rate Variability (HRV)). CWI was shown to have an initial decrease in parasympathetic activity, followed by a graduated increase over the session, resulting in a return to baseline or minor increase. These effects are less consistent and often require longer duration and repeated sessions to be noticeable​ [1, 8].

















*RMSSD **One acute session of cold water immersion or Nurosym neuromodulation (5 minutes) Over a single session, cold water immersion has an initial significant increase in sympathetic nervous system (fight or flight) activity, resulting in a decrease in HRV. As there is acclimatisation and recovery from the cold [1, 8]. 




Additionally, while CWI can reduce muscle soreness and perceptions of fatigue, the evidence on its ability to decrease inflammatory markers like IL-6 is equivocal, with some studies suggesting no significant impact. In a recent meta analysis looking at the impacts of CWI on inflammation in exercise performance and fatigue recovery, Xiao et al. 2023 found that there was no evidence that CWI reduced inflammation (as measured by IL-6) [9].


By contrast, in a recent clinical study Nurosym neuromodulation significantly reduced inflammation (-78% reduction in IL-6) in participants with elevated levels of inflammation (hospitalised with acute heart failure), over the length of a short hospital stay [3].


Nurosym: a non-prescription, clinically-validated neuromodulation deviceNurosym: a non-prescription, clinically-validated neuromodulation device


Nurosym is an innovative wearable device, which can be used while performing other daily activities. It is a safe CE-certified medical device in the EU, multiple designations of non-significant risk by FDA with 0 serious adverse events reported, with over 2,000,000 treatment sessions completed. In the past, stimulating the vagus nerve required a surgically implanted device. Nurosym is non-invasive and available without prescription via Nurosym website.





[1] Geng D, Liu X, Wang Y, Wang J (2022) The effect of transcutaneous auricular vagus nerve stimulation on HRV in healthy young people. PLoS ONE:


[2] Almeida A., Machado A., et al. 2016. The effects of cold water immersion with different dosages (duration and temperature variations) on heart rate variability post-exercise recovery: A randomized controlled trial. J Sci Med Sport: doi: 10.1016/j.jsams.2015.10.003.


[3] Dasari W., Akhtar K., et al. 2023. Effects Of Low Level Tragus Stimulation On Inflammation In Acute Decompensated Heart Failure. Journal of Cardiac Failure:


[4] Petersen A. & Fyfe J. 2021. Post-exercise Cold Water Immersion Effects on Physiological Adaptations to Resistance Training and the Underlying Mechanisms in Skeletal Muscle: A Narrative Review. Front Sports Act Living:. doi: 10.3389/fspor.2021.660291.


[5] Stavrakis S., Stoner J., et al. 2020. TREAT AF (Transcutaneous Electrical Vagus Nerve Stimulation to Suppress Atrial Fibrillation): A Randomized Clinical Trial. JACC Clin Electrophysiol:


[6] How Much Does a Cold Plunge Tub Cost in 2022? – Renu Therapy


[7] Buy Nurosym™ - Restore Health With Home Neuromodulation


[8] Jungmann M., Vencatachellum S. ,et al. 2018. Effects of Cold Stimulation on Cardiac-Vagal Activation in Healthy Participants: Randomised Controlled Trial. JMIR Form Res.


[9] Xiao F., Kabachkova A., et al. 2023. Effects of cold water immersion after exercise on fatigue recovery and exercise performance--meta analysis. Frontiers in Physiology:



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