Sports Medicine II

Environmental stress can adversely impact an athlete’s performance and pose serious health threatsAreas of concern

HyperthermiaHypothermiaExposure to the sunLightening storms

Athletic trainers require knowledge and information concerning temperature, humidity and weather to adequately make decisions regarding environmental dangersHas 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 preventableAthletes that train under these extreme conditions are at riskPhysiologically the body will continue to function if body temperature is maintainedBody 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 9-1-1 and/or get the person to the hospital A.S.A.P.!!!

Heatstroke

Heat Illnesses are Preventable!

Common sense and precautionConsume fluids and stay cool

Fluid and Electrolyte ReplacementBody requires 2.5L of water daily when engaged in minimal activity1-2% drop in body weight (due to dehydration) results in thirstIf 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, 17-20 ounces 10-20 minutes, 7-10 ounces

During exercise Every 10-20 minutes, 7-10 ounces

After exercise 20-24 ounces for every 1 pound of

weight loss

More likely to occur when exercising outdoors sweating heavily and engaging in strenuous exercisePrevent through hydration, don’t ignore thirst, and don’t rely on it being your indicatorGenerally only 50% of fluid is ever replaced and should therefore be replaced before, during and

after exerciseAthletes should have unlimited access to water to prevent decrements in performance and

hypohydration

Using Sports DrinksUse with activity longer than an hourMore effective than just replacing fluids with waterFlavoring results in increased desire to consumeReplaces fluids and electrolytesWater alone can prematurely stop thirst response and initiate fluid removal by kidneysSmall amounts of sodium help in retention of waterDifferent drinks have different nutrient levelsUse a drink with carbohydrate concentration of 6%Optimal CHO level is 14g per 8 ounces of waterMore CHO results in slower absorptionEffective for both short term and endurance activities

Identifying Susceptible IndividualsAthletes with large muscle massOverweight athletes (due to increased metabolic rate)Death from heat stroke increase 4:1 as body weight increasesWomen are physiologically more efficient with regard body temp. regulationOthers that are susceptible include, those with poor fitness, history of heat illness, or febrile condition

Gradual AcclimatizationMost effective method of avoiding heat stressInvolves becoming accustomed to heat and exercising in heatEarly pre-season training and graded intensity changes are recommended with progressive exposure over 7-

10 day period80% of acclimatization can be achieved during first 5-6 days with 2 hour morning and afternoon practice

sessions

Uniform SelectionBase on temperature and humidityDress for the weather and temperatureAvoid rubberized suits

Weight RecordsKeep track of before and after measures for first two weeksIf increase in temperature and humidity occurs during the season, weights should again be recordedA 3-5% loss of BW will reduce blood volume and could be a health threat

Acute Exertional RhabdomyolysisSudden 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 dysfunctionsevere case = sudden collapse, renal failure and death

Associated with individuals that have sickle cell traitShould be referred to a physician immediately

Sickle Cell Trait8-10% of African Americans have sickle cell traitIn most the trait is benignAbnormality in red blood cell hemoglobin structureWhen hemoglobin is deoxygenated, cells clump together causing blood cell to develop sickle shape making it easy to destroyCauses 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) Description Symptoms98.6 Normal No hypothermia95 Hypothermia n/a89.6-95 Mild Hypothermia Shivering,

confusion

82.4-89.6 Moderate Hypo Shivering stops, slow heart rate

Below 82.4 Severe Hypo Coma, may appear dead,Ventricular fibrillation

68 Brain 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 respirationProblems 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 85-90oFDeath is imminent when temp falls below 77-85oF.

PreventionApparel geared for weather to provide semitropical microclimate for body and prevent chillingWaterproof and windproof fabrics that allow passage of heat and sweat and allow movementLayers 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 problemsBe aware of hydration levels as well to enhance blood volume and heat maintenance

Common Cold InjuriesLocalized cooling can result in tissue damage

Formation of ice crystals between cells, destroys cells, disrupts blood flow, clotting may occurFrost nip

Involves, ears, nose, chin, fingers, and toesOccurs with high wind and/or severe coldSkin 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

FrostbiteChilblains result from prolonged exposure causing redness and swelling, tingling pain in toes and fingersDue to poor peripheral circulationSuperficial Frostbite involves only skin and subcutaneous tissueAppears pale, hard, cold and waxyWhen re-warming the area will feel numb, then sting and burnIt may blister and be painful for several weeksDeep Frostbite indicates frozen skin requiring hospitalizationRapid re-warming is necessary (100-110oF)Tissue will become blotchy red, swollen, painful and may become gangrenous

Precautions must be taken to protect athletes, coaches, athletic trainers and support staffLong Term Effects on Skin

Premature aging and skin cancer due to ultraviolet exposurePremature aging is characterized by dryness, cracking and inelasticity of the skinSkin cancer is the most common malignant tumor found in humans

Overexposure to Sun

Damage to DNA is suspected as the cause of cancerMajor types include basal cell carcinoma, squamous cell carcinoma and

malignant melanomaRate of cure is 95% with early detectionFair skinned individuals are more susceptible to these maladies

Using SunscreenCan help prevent damaging effects of UV radiationSunscreen 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 apply60-80% of sun exposure occurs before the age of 20Sunscreen use is at its highest March - November but should be used year round

(particularly between the hours of 10am-4pm)It should be applied 15-30 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 scenariosEmergency 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 obtainedOther 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 safetyIf 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 GuidelinesLightening 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 awayCount of 30 indicates inherent dangerCount 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 downIn actuality it is the return stroke of the lightening going back up after it has already hit the

ground

Lightening detectorHand-held instrumentAble to detect storm occurring within 40 milesAllows you to know level of activity and directionWhen it detects a lightening stroke it emits an audible warning toneInexpensive alternative to setting up contract with weather service