The rain can cool you off. In the summer this could be pleasant, but in cooler conditions, it can be a serious problem. Even a light rain can soak you through and cool you off dramatically. A heavy rain in cool conditions can rapidly cause Hypothermia. If you stop running, you can become chilled very quickly. Shivering is a key indicator of your core temperature - see the notes on Hypothermia on the previous blog entry on running in the cold.
- A thin rain jacket can provide important protection and comfort. It is unlikely to keep you dry - you will probably sweat under the jacket, but it will prevent a lot of the evaporative cooling as well as the cooling effect of heavy rain.
- Rain is a real pain if you wear glasses. Wearing a baseball cap can help protect glasses from the rain and keep the rain out of your eyes and face. A wide brimmed hat can make running in the rain much easier, especially if you are running for a protracted time. I have used the Outdoor Research Seattle Sombrero and found it worked well, though it looks rather strange.
- If you are running in the rain for a protracted period, it will cause problems with your skin. The skin will absorb the water and become softer (maceration). This can cause blisters and chafing. The use of compression clothing can minimize chafing and should be the first line of defense.
- There are various creams that can help protect your skin in the rain. I have used Hyrdropel and found it very effective, especially on my feet.
- It is also important to protect any electronics you carry when you run. Most sports watches, heart rate monitors and GPS devices are water resistant. Cell phones and MP3 players are generally not. For good protection, a dedicated case, like Otter Box works very well, but I have found a simple Ziploc bag, sealed and folded over works remarkably well.
- In heavy rain or fog at night, having your light source on your head can just blind you. Using a light that attaches to your belt, such as http://www.rei.com/product/737855 works better.
- Wear clothes that do not absorb much water. Cotton should be avoided in any weather, but some synthetic materials absorb more water than others.
- Use common sense and caution for thunder storms. A lightning strike can kill, so it is best to avoid running in thunder storms.
- I have tried various waterproof styles of running shoes, and would not recommend them. For running through puddles they may help, but in any serious rain it is hard to stop the water from running down your legs and into the shoes, or going over the top of the shoe. Once a waterproof shoe is soaked, it stays wet. I find it much better to wear a shoe that drains well than one that is waterproof.