Wild swimming - a boost for mental health, but what about our physical health?

In this guest blog, PhD student Elitsa Penkova at the University of Exeter Medical School, talks about a research study she is leading on which aims to determine whether wild swimmers are at a greater risk of experiencing symptoms of infections and contribute to a more comprehensive understanding of the health implications of freshwater recreation in the UK. Read more about the study and how people can take part here…

Wild swimming, or plunging into rivers, lakes, or the sea, is not just a niche hobby. Across the UK, more and more people are leaving behind chlorinated pools for natural waters, looking to re-connect with nature and boost their mental health.

And it’s not just anecdotal. A recent large-scale study conducted in collaboration with the University of Exeter Medical School found that wild swimmers reported higher levels of positive well-being, autonomy, and competence compared to those who swim in outdoor pools. Read the study here.

Clearly, there’s something special about immersing ourselves in these natural environments that goes beyond a simple exercise routine. But it’s worth asking - are we putting our physical health at risk in the process?

The hidden risks beneath the water

Even when natural waters meet official bathing water standards, they can still harbour pathogens that pose health risks. Bacteria and parasites like Escherichia coli, Cryptosporidium, and Giardia are known to cause gastrointestinal illnesses and can enter waterways through various routes - wastewater effluent, raw sewage, manure runoff, and even from bathers themselves as well as from other (non-human) animals using the water.

Rainfall can play a significant role here. It can increase faecal pollution levels and has been linked to outbreaks of illness during mass river swimming events (Hall, V., Taye, A., Walsh, B., Maguire, H., Dave, J., Wright, A., Anderson, C. and Crook, P., 2017. A large outbreak of gastrointestinal illness at an open-water swimming event in the River Thames, London. Epidemiology & Infection, 145(6), pp.1246-1255.) Yet, because these illnesses are often mild and self-limiting, they tend to be under-reported.

Most of the existing research on recreational water users and health risks focuses on coastal environments. That’s understandable, since beaches attract more visitors. But as freshwater swimming gains traction, we’re left with a knowledge gap.

Inland waters, such as rivers and lakes, can be subject to intense pollution, with reduced capacity for dilution, relative to the coast. Yet, we still know very little about who’s swimming in these environments, what their behaviours are, and what health outcomes they experience.
Understanding the health risks of freshwater recreation

To address this, researchers at the University of Exeter launched the National Health Snapshot study - an online questionnaire aimed at capturing the experiences of wild swimmers and comparing them to those of people who do not swim. Our goal is to quantify the risk of illness associated with freshwater recreation.

Previous work on coastal bathers have shown that people engaging in water-based activities are more likely to report symptoms of infection, such as earaches, stomach bugs, and other general signs of illness, compared to those who are not so keen to get wet. But this remains to be assessed for inland waters.

Our study will help determine whether wild swimmers are indeed at greater risk of experiencing symptoms of infections and contribute to a more comprehensive understanding of the health implications of freshwater recreation in the UK.

Want to get involved?

If you’re over the age of 16, living in the UK, and have not been swimming outside the UK in the past month, you are welcome to take part, whether you are a wild swimmer, but especially if you are a non-swimmer.

Why are non-swimming participants important?

People who stay out of water are a crucial part of this study. They give us an idea of how often symptoms of infection occur in the general population, helping us to see whether wild swimming in inland waters changes the likelihood of experiencing these symptoms, or not.

Take part here (it only takes a few minutes!): https://bit.ly/freshwater-swim-survey 

Find out more about the study here: https://www.ecehh.org/news/health-freshwater-bathing/