Sports Medicine II

Environmental stress can adversely impact an athlete’s performance and pose serious health threats Areas of concern Hyperthermia Hypothermia Exposure to the sun Lightening storms

Athletic trainers require knowledge and information concerning temperature, humidity and weather to adequately make decisions regarding environmental dangers Has caused a number of deaths over the years Must manage heat stress appropriately Hyperthermia

Dehydration  Signs of dehydration  Fatigue  Vomiting  Nausea  Exhaustion  Fainting  In severe cases, death  Thirst is not a good indicator of dehydration because by the time that you feel thirsty you are already 2% dehydrated.

Extreme caution should be used when training in the heat (overexposure could result in heat illness) It is preventable Athletes that train under these extreme conditions are at risk Physiologically the body will continue to function if body temperature is maintained Body must be dissipate heat to maintain homeostasis Heat Stress

Body Temperature can be affected by 5 factors: 1.Metabolic Heat Production:  Metabolism always causes an increase in body heat that depends on the intensity of the physical activity.  The higher the metabolic rate, the more heat produced.

2.Conductive Heat Exchange:  Physical contact with other objects can result in either a heat loss or heat gain.  e.g. Football players competing on artificial turf on a sunny afternoon will experience an increase in body temperature simply by standing on the turf. Body Temperature can be affected by 5 factors:

3.Convective Heat Exchange:  Body heat can be lost or gained depending on the temperature of the circulating medium (e.g. air or water). Body Temperature can be affected by 5 factors:

4.Radiant Heat Exchange: Radiant heat from sunshine increases body temperature. Body Temperature can be affected by 5 factors:

5.Evaporative Heat Loss:  Sweat glands in the skin allow water to be transported to the surface, where it evaporates, taking large quantities of heat with it.  When the temperature and radiant heat of the environment become higher than the body temperature, the loss of body heat becomes highly dependent on the process of sweat evaporation. Body Temperature can be affected by 5 factors:

Evaporative Heat Loss: (cont.)  A normal person can sweat about 1 quart of water per hr. for about 2 hrs.  Sweating does not cause heat loss. It’s the evaporation of the water that dissipates the heat from the body. Body Temperature can be affected by 5 factors:

Minor Heat Illness Heat Rash aka: prickly heat  Cause:  Usually occurs when the skin is continuously wet with un-evaporated sweat  commonly located on areas of the body that are covered with clothing.  Symptoms:  benign condition  associated with a red, raised rash, accompanied by sensations of prickling and tingling during sweating.  Treatment:  athlete should wash the area and replace their clothing with dry clothing.  hydrocortisone may be applied to relieve itching if needed.

Heat Illnesses  There are 4 heat illness to be aware of  Heat cramps  Heat syncope (fainting)  Heat exhaustion  Heat stroke

 Usually related to painful muscle spasms that occur most often in the calf and abdomen (although any muscle can be involved).  Excessive sweating causes loss of large amounts of water, and small quantities of sodium, potassium, magnesium, and calcium (electrolytes)  causing an...  imbalance in concentration of these elements in the body/muscles  resulting in...  painful muscle contractions and cramps. 1. Heat Cramps

 Person most likely to get heat cramps = someone in good condition, but has overexerted themselves in heat. Heat Cramps

 Prevention:  adequate replacement of electrolytes by slightly increasing level of salt in the diet  eat bananas (potassium), drink milk and eat dairy products (calcium).  DO NOT use “salt tablets”  Treatment:  ingestion of large quantities of water or preferably Gatorade  mild, prolonged stretching w/ ice massage of the muscle in spasm Heat Cramps

aka: Heat Collapse  Cause:  standing in heat for long periods or by not being accustomed to exercising in the heat.  peripheral vasodilation of superficial vessels results in hypotension (low B.P.): pooling of blood in the extremities.  Symptoms:  dizziness, fainting, nausea  Treatment:  lying down in a cool environment (rest) and replacing lost fluids. 2. Heat Syncope

 Cause:  from inadequate replacement of fluids lost through sweating  Symptoms:  the victim will collapse and  has profuse sweating  pale skin, cool, wet skin  mildly elevated temperature (<102 degrees F)  dizziness  hyperventilation  a rapid pulse. 3. Heat Exhaustion

 Person most likely to get heat exhaustion = person in poor physical condition who attempts to exercise in the heat.  Treatment:  most importantly,  immediate ingestion of fluids  placement in a cooler environment  rest  eventually  IV replacement of large quantities of water  more rest in a cool environment Heat Exhaustion

A serious, life-threatening EMERGENCY!  Cause:  The specific cause is unknown, but from the body’s cooling system shutting down/off  Symptoms:  sudden collapse with usual loss of consciousness  flushed, red, hot, dry* skin  shallow breathing  a rapid, strong pulse. 4. Heatstroke

 Most important sign -  core body temp. of 104 degrees or higher  can occur suddenly, without warning.  possibility of death can be reduced if the body temperature can be lowered to normal within 45 mins. Heatstroke

 Treatment  get the athlete into a cool environment  remove clothing and immerse the athlete in a cold water bath, or sponge him/her with cold water and fan with a towel.  replacement of fluids is not as critical as lowering the core temperature  CALL and/or get the person to the hospital A.S.A.P.!!! Heatstroke

Heat Illnesses are Preventable!

Common sense and precaution Consume fluids and stay cool Fluid and Electrolyte Replacement Body requires 2.5L of water daily when engaged in minimal activity 1-2% drop in body weight (due to dehydration) results in thirst If thirst is ignored, dehydration results in: nausea, vomiting, fainting and increased risk for heat illness Preventing Heat Illness

Fluid Replacement Guidelines (NATA)  Before exercise  2-3 hours, ounces  minutes, 7-10 ounces  During exercise  Every minutes, 7-10 ounces  After exercise  ounces for every 1 pound of weight loss

More likely to occur when exercising outdoors sweating heavily and engaging in strenuous exercise Prevent through hydration, don’t ignore thirst, and don’t rely on it being your indicator Generally only 50% of fluid is ever replaced and should therefore be replaced before, during and after exercise Athletes should have unlimited access to water to prevent decrements in performance and hypohydration

Using Sports Drinks Use with activity longer than an hour More effective than just replacing fluids with water Flavoring results in increased desire to consume Replaces fluids and electrolytes Water alone can prematurely stop thirst response and initiate fluid removal by kidneys Small amounts of sodium help in retention of water Different drinks have different nutrient levels Use a drink with carbohydrate concentration of 6% Optimal CHO level is 14g per 8 ounces of water More CHO results in slower absorption Effective for both short term and endurance activities

Identifying Susceptible Individuals Athletes with large muscle mass Overweight athletes (due to increased metabolic rate) Death from heat stroke increase 4:1 as body weight increases Women are physiologically more efficient with regard body temp. regulation Others that are susceptible include, those with poor fitness, history of heat illness, or febrile condition

Gradual Acclimatization Most effective method of avoiding heat stress Involves becoming accustomed to heat and exercising in heat Early pre-season training and graded intensity changes are recommended with progressive exposure over 7-10 day period 80% of acclimatization can be achieved during first 5- 6 days with 2 hour morning and afternoon practice sessions

Uniform Selection Base on temperature and humidity Dress for the weather and temperature Avoid rubberized suits Weight Records Keep track of before and after measures for first two weeks If increase in temperature and humidity occurs during the season, weights should again be recorded A 3-5% loss of BW will reduce blood volume and could be a health threat

Acute Exertional Rhabdomyolysis Sudden catabolic destruction and degeneration of skeletal muscle (myoglobin and enzyme leakage into vascular system) Occurs during intense exercise in heat and humidity resulting in: gradual muscle weakness, swelling, pain, dark urine, renal dysfunction severe case = sudden collapse, renal failure and death Associated with individuals that have sickle cell trait Should be referred to a physician immediately

Sickle Cell Trait 8-10% of African Americans have sickle cell trait In most the trait is benign Abnormality in red blood cell hemoglobin structure When hemoglobin is deoxygenated, cells clump together causing blood cell to develop sickle shape making it easy to destroy Causes enlarged spleen and could rupture at high altitudes

Hypothermia  hypo=less + thermia=temperature  having a core body temperature less than 95 degrees F or 35 degrees C.  Causes:  Prolonged exposure to cold temperature  Sy & Sx  Cold, shivering, nausea, confusion, and coma

Hypothermia  Person may fall asleep and die. Temperature (F)DescriptionSymptoms 98.6NormalNo hypothermia 95Hypothermian/a Mild HypothermiaShivering, confusion Moderate HypoShivering stops, slow heart rate Below 82.4Severe HypoComa, may appear dead, Ventricular fibrillation 68Brain activity stops

Hypothermia  Overexposure to cold can result in frost nip or frost bite.  The intensity of the cold exposure is dictated by the air temperature and the wind. Wind can enhance the feeling of cold in low temperatures.

65% of body heat is lost through radiation (head and neck 50%) 20% through evaporation 2/3 through skin and 1/3 through respiration Problems arise when heat lost exceeds heat production via metabolism Results in impairment of neuromuscular function Drop in core stimulates shivering but stops after temp. drops below 85-90oF Death is imminent when temp falls below 77-85oF.

Prevention Apparel geared for weather to provide semitropical microclimate for body and prevent chilling Waterproof and windproof fabrics that allow passage of heat and sweat and allow movement Layers and adjusting them are key to maintaining body temperature (during period of (in)activity) Inadequate clothing, improper warm-up and chill factor can lead to injury, frostbite, chilblains, and/or minor respiratory problems Be aware of hydration levels as well to enhance blood volume and heat maintenance

Common Cold Injuries Localized cooling can result in tissue damage Formation of ice crystals between cells, destroys cells, disrupts blood flow, clotting may occur Frost nip Involves, ears, nose, chin, fingers, and toes Occurs with high wind and/or severe cold Skin appears firm with cold painless areas that may peel and blister (24-72 hours) Treat with firm pressure, blowing warm air or hands in armpits (if fingers involved) Do not rub

Frostbite Chilblains result from prolonged exposure causing redness and swelling, tingling pain in toes and fingers Due to poor peripheral circulation Superficial Frostbite involves only skin and subcutaneous tissue Appears pale, hard, cold and waxy When re-warming the area will feel numb, then sting and burn It may blister and be painful for several weeks Deep Frostbite indicates frozen skin requiring hospitalization Rapid re-warming is necessary ( oF) Tissue will become blotchy red, swollen, painful and may become gangrenous

Precautions must be taken to protect athletes, coaches, athletic trainers and support staff Long Term Effects on Skin Premature aging and skin cancer due to ultraviolet exposure Premature aging is characterized by dryness, cracking and inelasticity of the skin Skin cancer is the most common malignant tumor found in humans Overexposure to Sun

Damage to DNA is suspected as the cause of cancer Major types include basal cell carcinoma, squamous cell carcinoma and malignant melanoma Rate of cure is 95% with early detection Fair skinned individuals are more susceptible to these maladies

Using Sunscreen Can help prevent damaging effects of UV radiation Sunscreen effectiveness is expressed as SPF (sun protection factor) Indicates how many times longer an individual can be exposed to the sun with vs. without sunscreen before skin turns red. Greater the susceptibility the higher the SPF should be used Should be worn by athletes, coaches and athletic trainers who are outside a considerable amount, and/or have fair complexion, light hair, blue eyes or skin that burns easily

Individuals with dark complexion should also apply 60-80% of sun exposure occurs before the age of 20 Sunscreen use is at its highest March - November but should be used year round (particularly between the hours of 10am-4pm) It should be applied minutes before exposure and re-applied after exposure to water, excess sweating, rubbing skin with clothing or a towel

#2 cause of death by weather phenomena NATA has established position statement due to number of athletes and coaches potentially exposed to lightening scenarios Emergency action plans must be set for this type of event Involving chain of command, monitoring of weather service, decision making regarding removal and return to field Lightening Safety

In the event of a storm, shelter indoors should be obtained Other guidelines Avoid large trees, flag/light poles, standing water, telephones, pools, showers, and metal objects (bleachers, equipment,umbrellas) Last resorts find car, ravine, ditch or valley for safety If hair stands up on hand you are in imminent danger and should get down on the ground but not flat as that increases surface area

Additional Guidelines Lightening is generally accompanied by thunder (except 20-40% of the time due to atmospheric disturbances) Flash-to-bang methods estimates distance away for the storm From time lightening is sighted to the clap of thunder count, divide by 5 to calculate the number of mile away Count of 30 indicates inherent danger Count of 15 seconds everyone should leave the field

NATA and National Weather Service recommend returning to the field 30 minutes following the last clap of thunder or lightening strike Major misconception is that lightening that is seen striking is coming down In actuality it is the return stroke of the lightening going back up after it has already hit the ground

Lightening detector Hand-held instrument Able to detect storm occurring within 40 miles Allows you to know level of activity and direction When it detects a lightening stroke it emits an audible warning tone Inexpensive alternative to setting up contract with weather service