Cold weather resistance training
Are you a hard-core lifter training in an unheated home gym? If so, read how the cold affects your body and how you can prevent some common cold injuries.
The USAF conducts one of the world’s premier Air Crew Survival Schools. This training addresses cold weather survival by stating in the instructor’s manual: “Cold is a serious stress source, even in mild degrees it lowers efficiency. Extreme cold numbs the body and dulls the will to do anything except get warm”. Cold numbs up the body by lowering the flow of blood to the extremities. (7)
There are multiple stresses on the body’s system, which wants to remain in homeostasis. Obviously, air temperatures below skin and core temperatures will cause a disruption in the balance of heat produced versus heat lost to the environment. Air movement will sweep away the dead air closest to the body, which accelerates the heat loss. Dry air with its lack of relative humidity bothers the smooth muscle surrounding the lungs and bronchial airways. (1)
Responses to the cold
Every organ in our body plays a part in maintaining the core temperature near the ideal of 98.6° F, and in making blood glucose and fatty acids available to increase metabolism and heat production. The blood vessels of the skin constrict to conserve heat by sending the warm blood to the veins deeper in the body.
If you are a master lifter, this may become a problem because the ability to conserve heat and adapt to the cold decreases as we age. Blood flow away from the skin and the degree of vasoconstriction is reduced. Another age related phenomenon is the resting metabolic rate is less in the old compared to the young person. Less internal heat is produced to keep us warm. In both cases, this can lead to lower core temperatures in the older lifter.
The difficulties from lifting in the cold come from the layers of clothing worn; they are simply awkward to wear. Plus, shivering interferes with muscle actions because both agonist and antagonist shiver at the same time causing uncoordinated muscle action.
Cardiorespiratory endurance decreases due to maximal heart rate reductions. When blood temperature drops below 98.6°F less oxygen is delivered. Lastly, blood flow to the skeletal muscles decreases. Now your muscles don’t have the nutrients to work hard.
Muscular endurance is also affected by the slower nerve conductions and the smaller recruitment of muscle fibers (1, 6). So what else can place limitations on your strength and power output?
Maximal power output declines due to an increase in the time it takes to form the cross bridges of actin/myosin. (6) The fluid in the muscle fibers tends to be thicker in the cold. This increases resistance to the movement of the actin/myosin cross bridge efforts. Finally, the chemical ATP production decreases. When ATP is not available neither is power output.
Hazards and preventive measures (4)
Frostnip, frostbite and hypothermia are preventable if signs and symptoms are recognized.
In frostnip, a part of the body chills with no permanent damage. The affected areas show white and firm to the touch with swelling and pain. A simple warming up generally controls the injury unless it is severely affected. Then treat for frostbite.
Frostbite permanently damages tissues by decreased blood flow and ice crystal formations. Areas will be red, swollen and painful. The cells die, but some may survive with proper treatment.
Gradually warm the area with water at 100-104 degrees. DO NOT rub with snow or warm by an open fire. Administer hot beverages without caffeine or alcohol. Continued exposure may result in Hypothermia.
Hypothermia (abnormally low body temperature) is life threatening and needs immediate attention. The body loses heat faster than it’s replaced.
Symptoms are gradual and subtle in appearance. They range from slower movement, clumsiness, longer reaction times, confused thinking and poor judgment. Victims rarely perceive the dangers and are unable to protect themselves.
Treatment in the early stages consists of moving the victim to a warm, dry setting and administering hot beverages. Non-alcoholic and no caffeine drinks are best. Seek medical attention.
Clothing is one defense against the cold. “Apparel must match the weather. It should provide a semitropical micro climate for the body and prevent chilling” (3, 7).
Insulation comes from the dead air surrounding each fiber. “The thicker the zone of trapped air,” “the more effective the insulation.” Layering adds dead air space.
“Clothing next to the skin must be effective” wicking moisture away “from the body’s surface to the next insulating material layer for evaporation”. Polypropylene insulates, dries quickly and is effective.
The best is synthetic, breathable, lightweight fabric that dries easily and retains its insulating properties when wet. “If the water vapor cannot evaporate through the clothing it will condense, freeze and reduce the insulation value of the clothing and cause the body temperature to go down.”(7)
Once clothing becomes wet, heat transfers outwardly at 25 time’s normal rate. Wet clothing “actually facilitates heat loss from the body because water conducts heat much faster than air” (5)
Modern Principles of Athletic Training (2) states “An athlete may fail to warm up sufficiently or may become chilled because of relative inactivity for varying periods of time demanded by the particular sport either during competition or training: consequently the athlete is exceedingly prone to injury.”
Even though you probably just left your nice warm home, you need to warm your muscles. It loosens the muscles, moves the blood faster, and increases the breathing rate. The colder it is the longer warm up. And the more intense the session the longer should the warm up be.
Summary: the triad of cold temperatures, heat loss, and an inadequate warm up are injury invitations.
- Warm up thoroughly before lifting.
- Protect yourself when lifting in the cold. Wear and layer quality-insulated breathable clothing.
- Cover your head.
- Recognize signs and symptoms of frostbite and hypothermia.
Keep in mind; there are NO MOSQUITOES in a winter weight room!
1. Armstrong, Lawrence E. PhD. Performing in Extreme Environments pages 77-106, Human Kinetics POB 5076, Champaign, IL. 61825-5076
2. Arnheim, Daniel D., Modern Principles of Athletic Training, pages 303-304, Times Mirror/Mosby College Publishing, 11830 Westline Industrial Drive, St. Louis, Missouri 63146, Seventh edition, 1989
3. Houston, Charles S. M. D., University of Vermont, Merck Manual of Medical Information, pages 1345-1347 Simon and Schuster Publishers, Inc. 1997 edition, 100 Front Street, Riverside, NJ 08075
4. Katch, F.I., Katch, V.L., McArdle, W.D., Exercise Physiology, pages 502, 503, 505,-521, 351 West Camden Street, Baltimore, Maryland 21201-2436 Lippincott Williams and Wilkins 1996 fourth edition
5. Micheli, Lyle J. M. D., The Sports Medicine Bible, pages 7-9, HarperCollins Publishers, Inc. 1995, 10 East 53rd Street, New York, NY 10022
6. The Journal of Strength and Conditioning Research. Nov 2002, volume 16 number 4 page 561
7. USAF survival instructors manual AFR 64-4 Volume 1985. Currently in use per the commanding officer 22 Aug 03.