Transcript Sports Performance – Water, Food Supplements and

Sports
Performance –
Water, Food
Supplements
and
Performance
Enhancing
Drugs
Learning Objectives:
1.
To understand the importance
of hydration and electrolytic
balance for sports performance.
2.
To know what makes sports
drinks effective.
Water – vital for the body
because:
 It
regulates body temperature.
 It carries nutrients and oxygen to all cells
in the body via blood plasma.
 Helps convert food into energy and
absorb nutrients.
 It is required for expiration.
 It removes waste.
 It protects and cushions vital organs.
Electrolytes
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The scientific term for the salts in the body
(e.g. sodium, potassium, chlorine)
Vital for the functioning of cells (esp muscle
cells). Involved in the transmission of nerve
impulses.
Ensure that nutrients and waste products are
exchanged.
Maintain the body’s pH level.
Electrolytes dissolve in water and are
therefore closely linked with water and sports
performance.
Dehydration & Electrolyte Loss
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Water and electrolytes are lost during exercise
through sweating (due to increased body temp).
Water is also lost during exercise due to increased
exhaling (due to increased breathing rate).
Levels lost are effected by temperature, humidity,
altitude, and the amount of exercise.
Water loss is greater in cold (as air inhaled is dry),
at altitude, or in hot (increased sweating), or in
high humidity (sweat does not evaporate and the
body cannot cool).
Problems of Dehydration
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Water loss causes thickening of blood
(reduces blood flow, increases HR).
This effects the body’s ability to cool itself
(vasodilation becomes difficult).
Rises in core body temp can lead to heat
stress, collapse, and death.
Fluid loss above 3-5% of bodyweight reduces
aerobic performance, impairs reaction time,
affects judgement, concentration and
decision making.
Problems of Electrolyte Loss
 Caused
by sweating (and/or poor diet).
 Leads to drowsiness and poor decision
making.
 Causes muscle weakness and fatigue.
 Causes muscle cramps.
 Can result in abnormal heart rhythm.
As electrolytes are dissolved in water any
change to water levels will effect electrolyte
levels and so the two are inter-related.
How to maintain hydration
and electrolytic balance
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Sports drinks? http://www.youtube.com/watch?v=qRuNxHqwazs&ob=av3n
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Considerations for before, during and after exercise/event.
Task: Research sports drinks. What claims do they make? What are the vital
ingredients that make them more effective than water? What do they
recommend for before, during and after exercise?
On one or two sides of A4 create an athlete’s guide to hydration and electrolytic
balance based on your research.
Recommended sites:
http://www.gatorade.co.uk/
http://www.guardian.co.uk/lifeandstyle/2009/jul/27/sports-drinks
http://www.poweradegb.com/
http://www.brianmac.co.uk/drinks.htm
Also, p48-49 of A2 textbook.
Temperature Regulation
 Core
body temperature is 37 degrees.
 This is constantly monitored and the body
reacts quickly to any changes in core
temperature.
 Changes in core body temp of just 1 or 2
degrees has a huge impact on sports
performance (see p47 A2 textbook).
Cooling / Body reaction to rise
in core temperature
 Heat
is lost through radiation, conduction,
convection, and evaporation.
 Heat is lost through evaporation during
sweating.
 Heat is lost through radiation and
conduction by vasodilation.
Keeping Warm
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If core body temp falls below 35 degrees we
begin to suffer from hypothermia.
Core body temp drops due to environmental
conditions (low temp and high winds).
Also due to fatigue (inability to keep warm
through shivering and other body functions).
To maintain core body temperature in cold
conditions performers may increase energy
intake, and wear warm, windproof clothing).
The Athlete’s Diet
There are numerous food supplements available for
athletes. However, research generally shows that
an athlete can meet all their nutritional needs
through a normal balanced diet which includes:
 A sufficient level of carbohydrates (with a range of
glycaemic index ratings).
 Enough fluids to remain hydrated or rehydrate.
 A diet balanced comprising (including carbs,
protein, minerals, vitamins, water, fat, and fibre) of
whole and unprocessed foods.
Optimal Weight and Fat
Percentage
A
performer’s optimal weight varies
greatly depending on the demands of
their sport.
 Body fat percentage can be measured
by BMI, bioelectrical impedance, or skin
callipers.
 Body fat percentage can be
manipulated by changing energy input
(eating) or energy output (training).
Food Supplements and
Performance Enhancing Drugs
 Research
your topic.
 Condense the information down to just a
few key bullet points.
 Write your key bullet points on A3 paper
and present your findings to the rest of the
group.
Topics:
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Creatine
Protein supplements
Herbal Remedies
Caffeine
Bicarbonate of Soda
Erythropoetin
Anabolic Steroids – Testosterone
Human Growth Hormone
Beta Blockers
Diuretics
Stimulants
Extended Learning Task
 Review
notes on water, food supplements
and drugs and complete the revision
questions on p60 of A2 textbook.