ANS 110: Exercise Physiology

What are the types of muscle?

Cardiac, Smooth, and Skeletal

What are cardiac muscles?

Heart muscles

What are smooth muscles?

Line arteries and digestive tract

What are skeletal muscles?

Their contraction and relaxation allows for limb movement

What is each muscle fiber of a skeletal muscle? What are their average sizes?

A single muscle cell, few mm to several cm

What do skeletal muscles consist of?

Sarcolemma, nuclei, glycogen granules, fat droplets, myoglobin, mitochondria, and myofibrils

What does myoglobin do?

Stores oxygen

What do myofibrils contain? What do these in turn contain?

Myofilaments which contain contractile proteins

What is used as energy for muscle contraction?

ATP, or adenosine triposhphate

What is anaerobic metabolism?

Where creatine phosphate and carbohydrates are used to produce energy without oxygen

What is aerobic metabolism?

Where carbohydrates, fats, and proteins are used to produce energy with oxyegn

What are the different types of fibers?

Dark/Type I, Light/Type IIa, and Medium/Type IIx

What happens with exercise?

Cardiac output and oxygen intake increase

What is cardiac output

Heart rate x stroke volume

What is oxygen intake?

The tidal volume/total air moved in a breath

What happens when oxygen intake increases? What is this limited by?

Respiratory rate increases, but is limited by locomotion respiratory coupling

What does peak oxygen uptake/VO2 Max represent?

peak power output/work capacity

Why do horses become fatigued with high intensity exercise?

Lactic acid build up and heat

Why do horses become fatigued with low intensity exercise?

They run out of fuel reserves and heat

What does exercise training do?

Increases efficiency

What does becoming more efficient include?

Lower heart rate for given intensity, better able to sweat, shift to fat utilization

What are the concepts of exercise training?

Specificity, reversibility, and individuality

What is specificity with exercise training?

training for the specific outcome; for example, endurance horses train by long distance training

What is individuality with exercise training?

Training for the individual horse, as stressors and responses will be different

Why are horses excellent athletes?

Have a huge cardiac output, high maximum oxygen uptake, high ability to sweat, release of RBC from spleen

Why do horses have such a high cardiac output?

They have a large increase in heart rate, from a resting 30bom to 240bpm with exercise

What is the max oxygen intake for a horse?

Up to 160 ml/kg/min

What is the max oxygen intake for a human?

65-85 ml/kg/min

What does the RBC release from the spleen do?

Increases oxygen carrying ability

What are the challenges for horses and exercising?

Hypoxemia, dehydration, breakdown, exercise related conditions

What is hypoxemia?

Horses breathing is related to breathing and strides, so they run at a lower blood oxygen than they need to, which can be problematic

What does breakdown mean?

Musculoskeletal injuries

What are some exercise related conditions?

EIPH, PSSM, RER, Anhidrosis, Thumps