Here are a few tips:
Apply petroleum jelly to areas that tend to experience friction, such as under your arms and your inner thighs. The rain can exacerbate this problem as your clothing gets wet, so protect yourself before you get dressed.
Don the proper clothing to keep yourself comfortable in the rain. A cap can help deflect water from your face. Putting on a water-resistant, lightweight jacket can keep the rain off your skin, but it can also trap heat as you begin to sweat. Instead, wear workout clothes that are designed to wick water away from your skin to allow your skin to breathe as you run without the clothing holding moisture from the rain.
Stick to wooded areas when possible, such as a public park trail, to allow the trees to catch much of the rain. Avoid high-traffic roads where the cars can splash you with water as you run or bike beside them.
Wear something reflective, such as a shirt or vest, if you’re running in the morning or evening when it can be hard for cars to see you if you exercise along a road. Some athletic shoes have reflective stripes to help cars see you. Also, wear old shoes that still provide good traction.
Watch for hazards such as large puddles, rocks that have washed into your path or slick, muddy areas. Reduce your speed as necessary to navigate around the hazards safely.
Place your electronic devices, such as an MP3 player or cell phone, in a plastic zip-top bag or waterproof case.