GOOD HORSE SCIENTIST

1. Exercise Physiology
•Driving force behind all types of work
•Conversion of stored energy to mechanical energy

2. What Influences Athletic Ability?
• Genetics
• Training
• Training
methodology
• Environment
• Nutrition
• Track/Arena
Surfaces
• Shoes
• Jockey
• Etc.

3. ATHLETIC
ABILITY
Heart size
Skeletal muscle
properties
Anaerobic
capacity
Gas exchange
Hemoglobin
concentration
Biomechanics

4. ENERGY
• Sources
– Carbohydrates
– Fats
• Effect on performance
– ↓ energy = ↓ performance
– Must meet energy requirement
– Monitor body condition
• ↓ body condition = negative energy balance

5. Energy Metabolism
• Aerobic
– With oxygen
– Carbohydrate & fat
– CO2, H2O & ATP
• Anaerobic
– Without oxygen
– Carbohydrate
(glycolysis)
– Lactate & ATP

6. Muscle
Glycogen
Blood Glucose
Anaerobic
Glycolysis
Oxidative
Metabolism
Pyruvate Lactate
ATP
Free-Fatty
Acids
Creatine
Phosphate
Myokinase
and CPK
Reactions
CO2and
Water
Lipolysis
Oxygen
Synthesis of ATP from aerobic and anaerobic metabolism.

7. Muscular System

8. Types of Muscle Fiber
• Type I
• – Slow contracting
• – ↓ glycolytic activity
• – Fatigue resistant
• – Aerobic metabolism
• – Long term/low stress
• work
• – Endurance
• Type II
• – Fast contracting
• – Fatigue quickly
• – ↑ Glycolytic activity
• – Quick energy bursts
• – Speed for longer
• distances
• – Primarily anaerobic

9. Breed Differences
Type I fibers Type II fibers

10. Energy For Muscle Contraction
• Walking
– Slow contractions
– Primarily type I
fibers
– Fat primary energy
source (very
efficient)

11. Energy For Muscle Contraction
• Trot and Canter
– Increased contractions
• Increased contractions
require more ATP
• Type II fibers
• Fat cannot be
metabolized
anaerobically

12. Anaerobic Glycolysis
• Fastest way to
produce ATP
• Less efficient than
aerobic glycolysis
– Less ATP
– Lactic acid produced
– Decrease muscle pH
– Fatigue/tying up

13. Horses that can generate a higher
proportion of energy aerobically will
outperform horses with lower
aerobic capacity

14. Estimated Types Of
Energy Used
Event Preformed
Energy
Anaerobic Aerobic
Racing QH 80% 18% 2%
Racing 1000 m 25% 70% 5%
Racing 1600 m 10% 80% 10%
Racing 2400 m 5% 70% 25%
Racing 3200 m 5% 55% 40%
Polo 5% 50% 45%

15. Estimated Types Of
Energy Used
Event Preformed
Energy
Anaerobic Aerobic
Barrel Racing 99% 4% 1%
Cutting 88% 10% 2%
Show Jumping 15% 65% 20%
3 Day (Cross
Country)
10% 40% 50%
Endurance Rides 1% 5% 94%
Pleasure/Equitati
on
1% 2% 97%

16. Cardiovascular System
• Delivers blood to
body
– O2 from lungs
– Nutrients from
GI tract

17. Cardiovascular System
• Heart rate (HR)
– Resting 30-45
– Exercising – 240 bpm max
• Stroke Volume (SV)
– Volume of blood pumped per
beat
– 800 – 900 mls
• HR X SV = Cardiac Output
– Can pump > 250 li/min
– Equivalent to 55 gal drum

18. Affect of Exercise On
The Cardiovascular
System
• ↑ metabolic activity in limbs = ↑ blood flow
• Three ways to increase blood flow
– Increase cardiac output
• HR and CO proportional to running speed
• Cannot ↑ HR beyond max
– Increase O2 carried in blood
• Splenic dumping can double O2 carrying capacity
– Redistribute blood flow
• ↑ to locomotive muscle
• ↓ to kidneys and small intestines

19. Respiratory System
• Respiratory Rate
– Resting - 8-20 breaths per min
• Exercise
– ↑ O2 consumption
– ↑ CO2 emission
• To increase air exchange
– ↑ Respiratory rate
• RR linked to stride freq.
• ↑ Tidal Volume (TV)
– Air inhaled or
exhaled in a breath

20. Locomotor-
Respiratory
Coupling (LRC)
• Galloping Horse
– 150 Breaths
– 12-15 liters of air
• Trotting Horse
– 70-85 Breaths
– 20-25 liters of air

21. Respiratory Problems
• Laryngeal hemiplegia
– Partial paralysis of larynx
– Inadequate gas exchange
– Surgical treatment
• Chronic Obstructive Pulmonary
Disease
– Decreases respiratory rate
– Hyperallerginc response to dust,
mold, irritants
– House outdoors
• Exercise Induced Pulmonary
Hemorrhage
– Bleeding in lungs
– Speeds above 14 m/s
– Variable effects
– Furosemide (Lasix)

22. Thermoregulation
• Importance
– Evaporative Cooling
(Sweating)
– Most important route
of heat dissipation
– Requires ample
blood flow to carry
heat from core to
surface
• Thoroughbred (race)
– 2.5 gal
• Endurance horse (50-
100 miles)
– 6-12 gal
• Three day event
(dressage/cross
country)
– 5-6 gal

23. Thermoregulation
• ↑ Exercise intensity > ↑ heat load > ↑ need for
heat dissipation
• Prevent dehydration to prevent thermal injury
– Provision of adequate water
– Normal diet
– Salt & mineral supplement

24. Thermoregulation
• Dehydration
– Electrolyte & pH disturbances
– Fatigue
– Gait incoordination (ataxia)
– ↑ risk of orthopedic injury
– Muscle damage
– Death
• Supplement electrolytes
– Beginning training program
– Adjusting to high temperature

25. Types of Training
• Endurance
– Enhances aerobic
system
• High intensity/Quick
burst
– Increases muscle mass
– Strength training

26. Influence of Training
• ↑ heart size
• ↓ HR at given speed
• Quicker recovery to given heart rate
• ↑ Capillaries
– ↑ O2 delivered to muscles
• Increase aerobic capacity

27. Influence of Training
• ↑ Muscle Cell Mitochondria
– ↑ O2 utilization per unit of muscle
• Muscle has quickest adaptation
to training of all body tissues

28. Conditioning Times of Body Structures
0
5
10
15
20
25
Muscles Ligaments Bones
Unfit
Fit

29. Signs of Fatigue
• Respiration rate > heart rate
– Inversion
– Hyperventilating
– Shallow breathing
– Shock
• Muscle soreness (lactic acid buildup)
• Ataxia
• Deydration

30. Conditioning is A Process That
Occurs Over Time