One of the most talked-about considerations for an open water swim is water temperature, more specifically, cold water temperatures. While many swimmers and triathletes chose to wear wetsuits to protect themselves from the cold, many elite swim races and channel swims specifically prohibit the use of wetsuits. Indeed, many times the distinction of swimming in “skins” is a badge of honor.
There are a few key principles of cold water swimming that you must understand. First, water draws heat from our bodies faster than air…much faster. This is why a water temperature in the mid 60s can result in hypothermia while an air temperature of the mid 60s is quite comfortable. Secondly, the human body can be trained to physiologically respond to cold water temperature. Research has shown that the best cold water swimmers can raise their core body temperature by two or three degrees, just by thinking about it! This is especially helpful to combat the 2-3 degree drop in body temperature that occurs immediately upon submersion in very cold water. These same swimmers are able to draw the blood in from their extremities (where heat escapes quickly due to a low amount of insulating body fat) toward their core where it protects the vital organs. Lastly, the best way to train your body to physiologically react to cold water exposure is repeated exposure.
Here are 9 tips on training for cold water swims:
1) Imitate the pros and raise your body temperature before getting in: My favorite trick is to pile on the clothing, drink coffee, and blast the heat in my car on the drive up until I’m uncomfortably hot.
2) Minimize the initial shock: Enter the water at zero entry so that you slowly wade in. Acclimate your feet first, then legs and core before putting your face in the water. Immersing your face will be the hardest part; most people will find themselves gasping for air at this point. Swimming with your head up out of the water until the gasping stops will keep you from taking in water. If you are entering from a dock, use the ladder to lower yourself into the water.
3) Keep moving: Once you are in the water, don’t stop unless you have to, and keep the stops as short as possible. As you swim, your body produces heat as a by-product, so use this to your advantage and be prepared to swim at a very fast pace.
4) Acclimate down: The Fall season is a perfect time to start cold water acclimation training, because the water temperature starts off warm and cools down gradually, allowing your body to ease into cold water swimming. Be careful in the spring, when you don’t have this same opportunity.
5) Dress appropriately: If you plan on using a wetsuit in your races, this is the time to break them in! If not, wearing two caps is allowed for most races. The cap on top should be a brightly colored latex cap for visibility reasons. The cap on bottom can be a latex, silicone, or thermal cap. If you experience uncomfortable numbness in your feet, most wetsuit manufacturers carry wetsuit booties (although these would not be legal for non-wetsuit divisions).
6) Gradually increase exposure: Have your initial cold water workouts be only a few minutes, and gradually increase to longer periods. The colder the water, the shorter the swims. Always carry a thermometer so you can make informed decisions.
7) Train out of the water: Taking cold showers, wearing light clothing in cooler weather, and taking ice baths are a few methods used by cold water swimmers to raise their cold water tolerance. For the ice baths, try sitting in the bath for 10-15 minute intervals with calisthenics to warm up in between. Always have someone supervise these ice baths.
8) Stay safe: Before you go out for a swim, inform someone that you are going out and when you expect to be back. Wear a watch to stick to that schedule. Always swim with someone else and/or with a boat escort. Have your boat escort carry a mobile phone. Stay close to shore in case a quick exit is required. Most importantly, you and everyone around you should constantly be monitoring for signs of hypothermia. Violent shivering (and following, the ABSENCE of shivering) slurred speech, numbness, and compromised brain function are all signs that you should get out and warm up. Do not hesitate to abort a swim if you or those around you feel uneasy or prudent.
9) Be prepared for what happens afterward: Get dry and into warm clothes as quickly as possible. Bring a thermos full of hot liquid to drink after your swim. It is normal to experience severe shivering within a few minutes of stopping. Try to warm up gradually; a warm shower is preferable to a hot shower. Dry your hair with a blow dryer or turn the heater up in your car. Do not attempt to operate a motor vehicle until you have warmed up enough to regain normal brain function and stop shaking.
Cold water swimming adds a whole new dimension of difficulty to open water swims. Miserable for some, rewarding for others, and a necessity for many. The key to being successful is training and preparation, and it’s definitely not something to be taken lightly! Learn the difference between being cold and being hypothermic, and always keep safety at the forefront of your mind.
Happy (Cold) Swimming!
- Mallory Mead
Open Water Marathon Swimmer