EDU2EXP Exercise & Performance 1 Environment and Exercise

EDU2EXP Exercise & Performance 2 Thermoregulation

EDU2EXP Exercise & Performance 3 Body temperature Different temperatures: –Surface / Skin –Core body –Inner ear –Rectal –oral

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5 Mechanisms of Heat Loss/gain Radiation –The release of heat via electromagnetic heat waves Conduction Convection –Carrying heat on air currents Evaporation

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7 Primary mechanisms At rest? During exercise??

EDU2EXP Exercise & Performance 8 Mechanisms of Heat Conservation Vascular adjustments Muscular activity –Voluntary physical activity –Involuntary- Shivering Hormonal adjustments

EDU2EXP Exercise & Performance 9 Mechanisms Facilitating Heat Loss Circulatory adjustments Evaporation (sweating) Hormonal adjustments

EDU2EXP Exercise & Performance 10 Circulatory Adjustments Two competitive cardiovascular demands exist during exercise in the heat 2)Peripheral blood flow to the skin must increase to transport metabolic heat from exercise for dissipation at the body’s surface

EDU2EXP Exercise & Performance 11 Evaporation depends on Temperature and humidity of air Convective air currents

EDU2EXP Exercise & Performance 12 Clothing However if sweat is not absorbed and drawn away from skin to be kept dry, -> overheating

EDU2EXP Exercise & Performance 13 Exercise in the Heat

EDU2EXP Exercise & Performance 14 Consequences of Dehydration Reduced plasma volume Increased submaximal heart rate Impaired ability to thermoregulate

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EDU2EXP Exercise & Performance 16 Hyperthermia Prevention –Drink fluids before and after and have breaks every mins –Clothing Treatment –Immerse in ice bath/ cold water

EDU2EXP Exercise & Performance 17 Clothing for the heat Loose fitting to allow convective air currents near skin Wet allows increased evaporation Colour –Dark = absorbs radiant heat –Light – reflects radiant heat

EDU2EXP Exercise & Performance 18 Factors Affecting Heat Tolerance Acclimatisation Exercise training Age Gender Body composition Hydration

EDU2EXP Exercise & Performance 19 Acclimatisation to heat Training increases heat tolerance As does 9-14 days of exercising in heat

EDU2EXP Exercise & Performance 20 Exercise in the Cold

EDU2EXP Exercise & Performance 21 Cold Physiological –Peripheral Vasoconstriction –Shivering –Increased consumption O 2 to compensate for that used in shivering - Cold muscle = decreased contractile force Particularly when fatigued Large inner muscles insulated and protected Peripheral muscles  decreased dexterity Behavioural adjustments –Huddle –Voluntary movement –Put more clothes on –Exercise indoors

EDU2EXP Exercise & Performance 22 Exercise in water in the cold Body loses heat 4 x as fast in cool water as in air the same temperature  Shivering

EDU2EXP Exercise & Performance 23 Exercise and Altitude

EDU2EXP Exercise & Performance 24 Exercise at Altitude –Reduced barometric pressure –Reduced relative humidity –Reduced ambient temperature

EDU2EXP Exercise & Performance 25 Immediate adjustments to altitude above 2300 m Hyperventilation –Chemoreceptors detect that not getting enough oxygen Cardiovascular –Increased HR and cardiac output –At rest and during submaximal exercise

EDU2EXP Exercise & Performance 26 Exercise Capacity at Altitude Aerobic capacity –1-3.5% reduction Vo2 max every 300m increase from 1500 m –Greater rate decline for trained athletes Circulatory factors –Decreased MHR and SV

EDU2EXP Exercise & Performance 27 Acclimatisation Adaptive responses to improve one’s tolerance to altitude Additional 610 m = 1 week

EDU2EXP Exercise & Performance 28 Blood volume –Increased RBC production –Increased hemoglobin content –Increase in overall blood volume and an increase in oxygen carrying capacity. Muscle adaptations Increased muscle capillary density Longer-Term Adjustments

EDU2EXP Exercise & Performance 29 Altitude Training Acclimation to altitude improves one’s capacity to exercise at altitude However inability to train at equivalent intensity  no improvement Vo2 max on return to sea level  Live High, Train Low ??? Does altitude training improve sea-level performance ??

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EDU2EXP Exercise & Performance 31 Summary Environment critical to optimal performance Be aware of environment in case of negative effects Use to your advantage –Heat Humidity –Cool –Altitude

EDU2EXP Exercise & Performance 32 Ergogenic aids

EDU2EXP Exercise & Performance 33 Ergogenic aids 1- stimulate CNS 2-supplemental fuel source 3- reducing or neutralising performance inhibiting metabolic by-products 4- facilitating recovery from strenuous exercise Substances and procedures believed to improve athletic performance. They can:

EDU2EXP Exercise & Performance 34 Caffeine Enhances endurance performance by –Increased alertness, concentration and reaction time –Elevated mood –Increasing time to fatigue –Reducing perception of effort May improve sprint & power performances

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EDU2EXP Exercise & Performance 36 Anabolic Steroids Synthetic derivatives of testosterone Designed to maximize anabolic effects –Enhance protein synthesis –Inhibit protein degradation Increase skeletal muscle hypertrophy and strength Facilitates recovery from high intensity training

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EDU2EXP Exercise & Performance 38 Associated Side Effects of Anabolic Steroids Personality changes Reduced sperm count in men Menstrual cycle disruption in women Masculinisation in women Breast enlargement in men Liver damage Cardiovascular disease Impotence in men

EDU2EXP Exercise & Performance 39 Blood doping Practice of illicitly boosting the total volume of RBC in order to enhance athletic performance. Benefits –>Increased RBC can carry more O2, which can improve an athlete’s aerobic capacity and endurance.

EDU2EXP Exercise & Performance 40 Side effects Increase in blood viscosity  heart has to work harder to pump the thicker blood and the blood is more prone to clot. Increased risk of heart attack, stroke and blood clots in the lung. The risk is exacerbated by dehydration which often occurs during endurance exercise.