United States Pony Clubs Manual of Horsemanship: Muscles and Energy Production

This set of vocabulary flashcards covers equine physiology, muscle contraction types, energy metabolism pathways, fiber types, and various conditioning principles and methods as described in the USPC Manual of Horsemanship.

Skeletal muscles

The muscles that produce movement (locomotion) by contracting or shortening; they can only pull and cannot push.

Myofibrils

Tiny thread-like filaments within a muscle fiber that contain smaller protein filaments known as myosin and actin.

Tendons

Tough bands of connective tissue that connect muscles to bones.

Fascia

A thin, tough connective tissue that encases muscle bundles and the muscles themselves.

Isometric contraction

A type of muscle contraction where the muscle has tension or tone but does not change in length, important for maintaining core strength.

Concentric contraction

A contraction where the muscle shortens and gains tension, causing joint extension or flexion.

Eccentric contraction

A contraction where the muscle lengthens as it gains tension, helping counteract gravity and allowing for controlled gaits.

Adenosine triphosphate (ATP)

A molecule created from stored food (glycogen) that is broken down to provide usable energy for cellular processes.

Aerobic metabolism

Energy production that uses oxygen and glycogen (from carbohydrates and fats) to move muscles at a fairly low rate that can be sustained for long periods.

Anaerobic alactic metabolism

Energy production without oxygen or lactate, using glycogen and creatinine phosphokinase for intense bursts of energy lasting only $10$ to $20$ seconds.

Anaerobic lactic metabolism

Energy production without oxygen using glycogen that produces lactate (lactic acid) as a toxic waste product, resulting in fatigue and a burning sensation.

Type 1 fibers (slow-twitch)

Muscle fibers that are slow to contract, require oxygen (aerobic metabolism), and are slow to fatigue; important for stamina and posture.

Type 2 fibers (fast-twitch)

Muscle fibers that contract faster than Type 1, require little or no oxygen (anaerobic metabolism), and fatigue more quickly; divided into subtypes A and X.

Neurogenic muscle atrophy

A condition where muscles decrease in size due to a problem with the nerves supplying them, potentially causing both Type 1 and Type 2 fibers to shrink.

The Spleen

An organ that serves as a reservoir for extra red blood cells, releasing them into circulation during exercise to increase oxygen transport.

Inversion

A state of distress where a horse's respiratory rate is higher than its heart rate, indicating the horse is too hot and trying to dissipate heat by panting.

Anhidrosis

A condition in which a horse sweats very little or not at all, preventing it from cooling down quickly and resulting in elevated pulse and respiration.

Interval training

A conditioning method where work periods are set apart by rest periods to allow the muscle, heart, and respiratory rates to partially recover.

Tapering

The practice of reducing exercise or fitness work just prior to a big competition to enhance performance by providing extra energy.

Long, slow distance work (LSD)

Aerobic conditioning involving trotting and slow cantering to build a base of cardiovascular fitness and endurance.

Oxidative capacity

The ability to provide oxygen to muscles and for the muscles to effectively use that oxygen.

Gas exchange

The process of exchanging oxygen for carbon dioxide, which takes place in the alveoli and small blood vessels of the lungs.