Blisters can cause big problems for your workout considering how relatively small they can be.  Prevention is key to avoiding a premature ending to your workout and/or missed sessions.  

What are Blisters?

     Blisters that occur from exercise are friction-induced burns.  "Pockets" of liquid form in the upper layers of the skin where rubbing from shoes, clothing, and/or sports equipment damages the top layer of the skin, causing it to separate from the lower layers.  The fluid commonly present in blisters is known as serum.  Serum is the watery substance of blood that remains after the clotting factors and red blood cells have been removed.  Blisters may also be filled with blood if a small blood vessel near the surface is ruptured and leaks into the space underneath the damaged top layer of skin. 

     A precursor to a blister is known as a "hot spot."  This presents itself as redness and warmth over the area exposed to the friction-causing source.  Exercise-induced "hot spots" and blisters typically form on the heels, toes, soles of the feet, and palms of the hands.  Blisters form more readily when the skin is moist and the conditions are warm.

Blister Prevention:

• Wear properly fitted shoes.  Ensure that the seams inside the shoes are flat.  If shoes are new, "break" them in with lower levels of activity.
• Wear moisture-wicking socks to keep feet dry.
• Wear two layers of socks (thin first layer and a thicker outer layer).  Wearing two socks places the friction point between the two socks and not your foot and the sock.
• Apply petroleum jelly, talcum powder, tape, and/or an adhesive bandage over "hot spots."
• Wear gloves when weight training or using other hand held devices during exercise.

Blister Treatment:

• If the blister is not painful and has not broken, try to leave it intact.  The skin acts as a barrier against bacteria reducing the risk for infection.  Place an adhesive bandage or foam "donut" pad over the blister.
• If the blister is painful, the fluid can be drained by making a small hole with a sterilized needle or pin at the edge of the blister.  Wash your hands with soap and water and wipe the blister and surrounding area with rubbing alcohol before draining.  Do not remove the overlying skin as it will help protect against infection.  Clean the drained blister with an alcohol wipe, apply a triple antibiotic ointment, and cover with an adhesive bandage.
• Do not drain blood blisters. 

Contact your physician before you attempt to drain a blister if you suspect it is infected, you are a diabetic or have poor circulation.  Signs of an infection include unusual redness and warmth around the area of the blister, red streaks going away from the blister, pain, and/or pus.

Resources:

www.sportsinjuryclinic.com

www.sportsmedicine.about.com/od/footandankleinjuries/a/Blister.htm

www.wellsphere.com/wellpage/foot-blister-care