Friday, July 9, 2010

Summer running vs. Winter Running

Being an ultra marathon runner, I have run in all kinds of conditions. Having a 5 day a week schedule, I really can't decide to run if it is too cold or too hot. I just have to be prepared. I have learned to adapt to all running conditions.
During the previous winter, I ran in conditions where the temperature didn't get above 20. I would dress in just 1 pair of running polyester black pants, wool socks, long sleeve polyester shirt, windbreaker, winter hat over my ears, gloves and occasionally little hotties. Unfortunately it wasn't enough to keep my camelbak from freezing-the tube. I even had to stop into a local 7-11 to get it to un-freeze. I did find that sticking the tube down my shirt to be helpful. I really prefer not to run if it is snowing or if there is ice. I don't want to make a bad running condition worse by ending up in the hospital.
During the summer months, I dress in a pair of shorts, cotton socks, and a no sleeve running top. I find it helpful to soak my hat in water before prior to putting it on. I also try to go as late as possible. One night, it was 93 when I left the house at 7:35, but noticed it was 97 in the sun. There was a lot of shade and I brought about 2 qts of water for an 8 mile run.
I also have been trained to recognize the signs of heat stroke and heat exhaustion.

The two articles below are from my marathon coaches, Patti and Warren Finke. I am forever grateful to their great coaching. I hope you find it useful.


Running in The Heat

by Patti and Warren Finke, Team Oregon

"It was 85 degrees and 90% relative humidity. I remember trying to stay with Bill Rodgers but being unable...feeling funny...then I woke up in a tub of ice. I lost 20 or 30 minutes. My body temperature was over 108." - 1994 Comrades Marathon Champion Alberto Salazar discussing his life threatening heat stroke episode at the 1980 Falmouth Road Race.
Performance may be influenced tremendously by temperature. As air temperature rises, the combination of environmental heat and increased body heat from exercise may result in adverse effects ranging from decreased performance to death. The best defense the runner has is to prepare himself for warm weather conditions and understand how to recognize and deal with the effects of heat. For runners who may compete in hot weather it is critical for performance and safety to develop and maintain heat acclimatization.
The human body is able to maintain a fairly constant temperature under varying environmental conditions. To do this, it must be able to gain or lose heat. The core temperature is regulated to remain relatively constant, but the temperature of the shell, the skin and the tissues directly beneath it, varies directly with environmental conditions. The hypothalamus in the brain controls the body temperature and calls into play either heat loss or heat production mechanisms. Regulation comes in response to changes in the skin or blood temperature.
Normal metabolism in the body produces heat. Increased heat production can come from higher metabolic rates, disease, shivering or exercise. During exercise, the increased metabolic rate and energy production both generate heat. Most of the heat gain is due to the lack of efficiency of the body. It converts only 20-30% of energy produced into work; the rest is dissipated as heat. Heat gain or loss is governed by the following physical means:


  • Conduction - transfer of heat to or from the body by direct physical contact.



  • Convection - transfer of heat by movement of air or water over the body.



  • Radiation - radiation of heat from the body into space and absorption of radiation, (sunlight) on the bodies surface.



  • Evaporation - loss of heat by the body when converting sweat to vapor. In a cold or cool environment, conduction and convection, along with some evaporation of sweat, can maintain the heat balance. As the temperature rises, evaporation of sweat becomes the main way of controlling the rise in core temperature. Evaporation can keep the body's exercising temperature in the normal range of 102-105 F under normal environmental circumstances.

    PERFORMANCE

    Several studies have shown that the optimum temperature for long distance running performance seems to be around 50-55 degrees Fahrenheit. Above and below this range performances degrade as much as 2% for every 5 degrees. Three additional environmental factors can interact to alter performance further. They are relative humidity, air movement, and radiation. High humidity, because it inhibits evaporation, has the same effect as increasing the ambient temperature. This effect is worse for higher temperatures where it can increase the effective ambient temperature by as much as 10 degrees.
    Air movement over the body enhances the ability to lose heat by convection and evaporation. Movement is generated both by the runners speed and by any prevailing wind. These can combine to lower the effective temperature by as much as 8 or 9 degrees while increasing evaporation and fluid loss. Running downwind cancels out this cooling effect.
    Direct sunlight adds heat to the body by radiation. The effective temperature increase can be as much as 8 or 9 degrees.
    It is easy to see that by combining 80+ degree temperatures with direct sun exposure and high humidity serious performance degradation will occur in long distance races.

    HEAT ILLNESSES

    Special caution should be advised when the temperature is above 80 F or when the relative humidity exceeds 50-60%. Running unwisely under environmental heat stress may lead to a variety of heat illnesses which can be life threatening. These illnesses are caused by three factors: increased core temperature, loss of body fluids, and loss of electrolytes. While running in the heat, monitor your condition for signs of weakness, dizziness, nausea, disorientation, cessation of sweating and piloerection, (the standing up of body hairs). If these signs occur, stop running and start the appropriate treatment. They could be symptoms of any of the major heat illnesses described below.

    Heat Cramps

    Salts can be lost in the sweat while running in the heat. If they are not replenished properly, muscle pain and cramps can occur. The body temperature does not become elevated. Prevention can come from heat acclimatization, ingestion of large amounts of water and by increasing the daily salt intake several days before the heat stress. Treatment is rest in a cool environment and replacement of lost salts.

    Heat Exhaustion

    Poor circulatory response to heat and reduction of blood volume due to increased sweating can lead to symptoms of general weakness, dizziness and nausea. The skin is usually cool and pale, but the person is probably still sweating. Body temperature is not elevated to dangerous levels (under 106F). Exercise must be stopped. Treat by rest in a cool environment, ingestion of cool liquids and cooling the body externally with water or ice.

    Heat Stroke

    When the body's temperature regulating system fails, excessively high body temperature and heat stroke can result. This is a serious condition which, if untreated, may well lead to death. It requires IMMEDIATE medical attention. The symptoms are dry, warm and red skin, a reduction or loss of sweat and a body core temperature over 106F. Treatment is to immediately stop exercise, seek medical attention and start cooling the body with ice packs and cold water. The person may or may not be conscious. Cool liquids may be consumed if the person is conscious.

    REDUCING HAZARDS

    There are ways to reduce hazards when running in the heat and/or humidity, most are common sense: Check the conditions before exercising and adjust your plan if needed. Slow the pace or decrease the duration of activity if training when hot or humid. If racing when hot and humid, realize that performance will less than expected. If the event is not a key one, relax and save the bigger effort for a cooler day.
    Run in the early morning or late evening to avoid the heat of the day. In many climates, late afternoon is the hottest time of the day and running then should be avoided.
    Find a shady road or trail to run on.
    Dress accordingly, wear as few clothes as you decently can. Try loose fitting white shorts and a white mesh top to reflect the heat and to permit evaporation. Protect your head from intense sun with a lightweight hat that can breathe. The back of the neck can be protected by the hat or a cotton kerchief. Ice can be wrapped in the kerchief and carried under the hat.
    Drink fluids while running. Carry a water bottle or pick a route with water fountains. Drink 6-8 oz. of water for every 15-20 minutes of running. Also pour water over your head and chest. Dehydration has been shown to adversely effect performance after as little as 45 minutes of activity.
    Weigh yourself after workouts and replenish lost water at the rate of 1 pint per pound of weight loss. Body weight should be back to normal before the next workout.
    Try hyperhydration by drinking 2-4 cups of water 30 minutes before running.
    Be aware of lost electrolytes if you've sweated excessively. Put an appropriate amount salt on foods and eat bananas and citrus fruit.
    Avoid excess protein intake. Protein metabolism produces extra heat.
    Know the signs and symptoms of heat illness and their treatments. If you have any of the symptoms, stop running, get to a cool place and consume cold fluids.
    If you are going to compete in an event in hot conditions, acclimatize first.

    HEAT ACCLIMATIZATION

    With proper acclimatization the body can perform as if it were in temperatures 10 to 15 degrees cooler. Acclimatization is the process of adapting your body to be able to run more efficiently under hot environmental conditions. When it is hot the blood goes to the skin for cooling the body as well as to the working muscles. This increases the workload of the heart and the exercising heart rate. Intensity of exercise will need to be reduced when running in the heat and when acclimatizing for proper adaptation. The body makes several adjustments during the heat acclimatization process. The circulatory adaptations to acclimatization provide better transport of heat from the core to the skin. There is better distribution of the blood to regulate temperature. This frees a greater portion of the heart output for the working muscles. Sweating mechanisms undergo complementary changes. Sweating starts at a lower body temperature and the capacity for sweating nearly doubles. The sweat becomes more dilute, contains less salt, and is more evenly distributed over the skin. Major changes occur during the first week of heat exposure and are mostly complete after 10 days.
    Heat acclimatization can also be lost in 10 days. This is why it is important to wear extra clothing during unusually cool summer weather, ( like the summer of 1993 in the northwest ). You should try to maintain acclimatization for typical hot weather conditions which could occur on short notice at your next race.

    Ways to Acclimatize

    Begin early in the season when the temperature is moderate and wear one more layer of clothing than usual on 3 runs per week. If you would normally wear a T-shirt wear a long sleeved one or a jacket. If you would normally wear shorts, wear cross training shorts or tights. This early constant acclimatization works well in climates such as in Oregon where the weather is often unpredictable and occasional hot days are experienced relatively early in the year. To develop and maintain acclimatization in weather that is unseasonably cool or in preparing for a race in a warmer climate assume that each layer of dry clothing or degree of coverage, (i.e. going from short to long sleeved shirt or from shorts to tights), is equivalent to 15 or 20 degrees in temperature.
    Adding a waterproof jacket such as Tyvec provides a hot, humid microatmosphere and prevents evaporation which would normally cool you once your clothes became wet.
    If the weather suddenly turns hot, reduce the training load; run slower and less distance. Slowly build back up to usual mileage and intensity. Work on heat acclimatization every other day and make certain to replace lost fluids. Run in the cooler part of the day on the nonacclimatization days. Do not overdo and get heat symptoms.
    If you plan to race under hot conditions, remember that acclimatization takes about 10 days. Plan to be acclimatized a week in advance. During the week before the event, avoid extra heat stress which may dehydrate and fatigue you for the race.

    FLUID AND ELECTROLYTE REPLACEMENT

    Optimal performance depends on proper hydration. Dehydration or excessive loss of body water reduces the amount of time you can exercise as well as necessitating slowing down. Changes that take place at the cellular level adversely effect muscle contraction. Water losses of 2% or more of body weight impair circulatory function, create heat imbalance and degrade performance. You should drink 6-8 ounces of fluid every 15-20 minutes during exercise. You can also hyperhydrate by drinking 2-4 cups of cold fluid 15-30 minutes before exercise. Sweat is comprised mainly of water and sodium and chloride ions. These ions are known as electrolytes. Other electrolytes are also present in small amounts. Studies of electrolyte balance during and after exercise have shown increases in the electrolytes in the blood, but these changes are probably due to water loss and muscle use.
    There is some evidence that glucose electrolyte solutions (sports drinks) help replenish body water better than plain water. While the electrolytes are probably not necessary for replacement in runs of marathon length or shorter, they may improve fluid absorption by the body and encourage further drinking by stimulating the bodies thirst mechanism. In runs longer than 90 minutes, the carbohydrate in sports drinks helps spare liver glycogen depletion. For optimum absorption drinks should contain 5 to 10% carbohydrate (glucose or sucrose) and should be cool (40-50 degrees F).
    If running in the heat for several consecutive days, try to replace fluids and eat a balanced diet. Add salt to foods and select foods high in potassium such as bananas and citrus fruits. Salt tablets are unnecessary and may be harmful when not taken with adequate water.



  • Getting the Most Out of the Winter Season

    by Patti and Warren Finke, Team Oregon
    Can't quite get out the door? Hate getting wet? Just don't wanna do it? Yes answers to these questions trouble many runners in the winter time. Let's look at some suggestions to keep you training throughout the winter or wet months so that you're ready to race again come spring.

    Periodicity of Training

    We've talked several times about the importance of planning a season of rest for the most effective racing and running enjoyment. In Oregon, the winter season is the most natural season to give yourself this break from really hard training. The rest period should be 6 -10 weeks of maintenance running and supplemental activities. The supplemental training and strength building that we talked about in the Cross Training article are most appropriate during this time. There are many indoor substitutes for running that can be beneficial to runners. Try the exercise bike, stepper, aerobics class or cross country ski machine 2-3 times a week to stay really dry and add a circuit weight training program. Plan to run 2-3 times a week as a maintenance level. Several suggested schedules to maintain are listed below. The supplemental training can be substituted for any of the run days except for the long run.

    Recreational or Fitness Runner

    If you have been running a short time, routinely run 10-20 miles per week and have completed an occasional 8 k race, this type of weekly schedule will allow you to run events up to the 10k distance (with 6 mile long run) and still enjoy the camaraderie recreational fun runs.
    S         M         T         W         T         F         S
    4-6miles  0       2-3mi    30-45 min   2-3mi  30-45 min     0
    supplemental        supplemental
    and/or weights      and/or weights
    

    Recreational Racer

    If you typically run 20-30 miles per week, perhaps have completed your first marathon, this schedule will allow you to run an occasional event and be able to start training for a fall marathon in the spring.
    S         M         T         W         T         F         S
    8-12miles 0       4-6mi  45-60 min    4-6mi   45-60min      0
    supplemental        supplemental
    and/or wts           and/or wts
    

    Advanced or Racer

    If you run well over 30 miles per week, races often and want to complete a spring marathon or race well then, this schedule will get you ready to add a basebuilding period for the specific marathon or race training.
    S         M         T         W         T         F         S
    10-15mi  0-3mi    5-8mi   60-75 min   5-8mi   60-75 min   0-3mi
    supplemental        supplemental
    and/or wts          and/or wts
    

    Running in the Cold

    Cold is usually not as hazardous for the runner as is heat. With exercise metabolism, the body is able to maintain a constant core temperature in air temperatures as low as -22F. This is regulated by internal mechanisms and not necessarily by the heat produced from exercise. Shivering can be seen during exercise when the core temperature is low. Under this stress, oxygen consumption is higher than when doing the same amount of exercise in warm weather. Common sense tells you to be comfortable while running; this is also true in cold weather. Both body fat and clothing act as heat conserving mechanisms. High body fat is not conducive to good performance and is not common in runners, so most must learn to dress warmly. It is often difficult to determine how many clothes to wear in winter conditions. The heat generated by your body can be seven or eight times as great when running as it is at rest leading some runners to overdress at the start of their run. On the other hand, if you are dressed to be "just right" when you are running hard and you must slow down or walk due to fatigue or injury, you risk the threat of hypothermia. When you couple this variation in the body's heat generating capability with the rapid changes possible in winter weather and the loss of insulating properties of clothing when it is wet, the following guidelines emerge.
    1. You are better off to overdress than underdress. Very few people die from overheating in the winter, many from hypothermia.
    2. The more adaptable clothing is the better. Layers of clothing trap and warm air between them to act as insulation. You should use layers that you can remove as you get warmer and add as you get colder and clothing which can be zipped, buttoned, rolled up or down to provide more or less cooling.
    3. You should attempt to stay as dry as possible. If clothing becomes wet either through sweating or external sources (rain, snow), it can conduct heat away from the body. Regulate your clothing so it doesn't become sweat soaked, use materials such as thermax or poly-pro which wick moisture away from your skin as you sweat, and wear a rainproof shell which sheds moisture and does not soak it up when it is precipitating.
    When deciding what to wear for your run, first check the temperature as well as the conditions outside. Running with bare legs in cold weather is not advised. The red color of the skin shows that a great deal of the blood is detoured to the skin trying to keep the body warm and is not going to the exercising muscles where it is needed most. Cold muscles feel tight and are more susceptible to injury, especially pulls and strains. We suggest lycra tights or other leg covering when the temperature is below 40. Many options in materials for tights are available, from water resistant to extra warm fuzzy polypro which can be worn as the conditions change. Fabrics that are waterproof, but can still breathe are best for external layers. Gortex works quite well if you don't sweat a great deal. Polypropylene is excellent next to the skin as it wicks away the water and allows a warm air layer to remain. A major part of heat loss is through the head, so wear a hat or ski headband to help keep warm. Gloves are important as well and range from cotton to polypro to gortex. If it's wet polypro keeps hands much warmer and the gortex mittens on top on a rainy day are a sheer indulgence.. You can remove gloves, hat or layers of clothing as you become warmer. Check your local running store for the latest in winter running fabrics.

    Safety Concerns

    After daylight savings time is over, many of us run mostly in the dark. The dark presents a number of safety problems. It is also often raining when it's dark, making runner visibility to cars very difficult. It is important to wear apparel that can be seen by motorists and cyclists. The best is a reflective vest. Jackets, T shirts, tights and shoes can be purchased with reflective strips. The most visible spots seem to be on the moving parts such as shoes,legs and arms. Not all shoes come with reflective strips or the newest "flashing lights", but you can buy stick on reflective material. The best places to run are areas where its lighted. Pick lighted streets with sidewalks or lighted bikepaths. Some running tracks have runner lights that can be turned on.
    It makes sense to run away from cars, such as on a bike path or the sidewalk. Always run facing traffic so as not get hit from behind. The most dangerous crossing is in front of a car turning right with the driver only checking out what's coming. Never step in front of this car without recognition from the driver. Our favorite trick to alert drivers that they need to look is to run behind the car and slap the trunk to make them aware I'm there, then smile and say "you need to look both ways".
    Women face more safety problems and must always be careful when running alone. The early morning hours seem to be a time when perverts are out. The best ideas are to run only in areas that you know are safe, and run with a companion or companions. Try to hook up with other runners or get a canine companion. Dogs can be fun to run with and great protection. They need to be trained for endurance, should run on a leash and never disagree with you. The Oregon Road Runners and other dealers have alarms available that you can set off to alert others. It would be a good idea to sign up for a personal safety program. These are often available from local Police departments.

    Running on Ice and Snow

    When running on any kind of slick or uneven surface, there is risk of injury both from falling and from altered running style. If you must run on ice and snow, you can modify your running shoes to provide enhanced traction by adding inexpensive sheet metal screw studs. Go to the hardware store and buy twenty #6 hex head sheet metal screw 3/8" to 1/2" in length. These are the ones that have the hex head with the recessed screwdriver slot. The top has a sharp circular ridge ideal for grabbing in ice.
    Carefully screw the screws into the outersole of your running shoes in the locations shown as close to the outer edge of the sole as possible avoiding any air bladders, flashing lights, etc. (This will probably void your warranty).
    This should give you ample traction for running or racing on packed snow and ice. Because the studs are only around the perimeter, they will still allow ample traction from the center of the shoe when running across bare pavement. Caution, do not use on hardwood, linoleum or tile floors!
    Planning for the cold wet dark months of winter can keep your running on track. We hope we've given you a few ideas to keep getting you out the door this winter.

    Team Oregon Running Tips are Copyrighted by wY'east Consulting and Team Oregon which reserve all rights to republication.

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