Equine lecture 3 Flashcards
When is blood/muscle lactate produced
Anaerobic energy production
Characteristics of blood/muscle lactate
Acidification of the muscle contributes to fatigue and prevents complete exhaustion of muscle glycogen stores
The end product of anaerobic glycolysis and pyruvic acid that is converted to lactate
Lactate is not a waste product but a by-product of anaerobic pathways in the muscle
Red blood cells do not have mitochondria → obtain ATP from anaerobic glycolysis of glucose taken up from the plasma and produce lactic acid that diffuses back out into the plasma.
How is blood/muscle lactate formed
During exercise lactate is formed in working muscles and the flow of lactate is from muscle cells into blood plasma and further into tissues such as the heart and liver that may use lactate for energy or glucose production. A substantial proportion of lactate that is produced in the muscle may also be taken up by the red blood cells.
What happens with blood/muscle lactate during recovery
During recovery, the direction of lactate flow is reversed, from red blood cells to plasma, and the main user of lactate is the skeletal muscle. Light exercise during the recovery period that increases muscle energy requirements will also increase the rate of lactate disappearance.
What happens with blood/muscle lactate when training stops
When the exercise is stopped, the rate of energy consumption remains elevated and blood lactate concentration continues to increase, with peaks 2-10 minutes post-exercise
* During exercise, the liver uses lactate by converting lactate back to glucose
* The heart will use lactate directly for energy
* During recovery, the major consumer is skeletal muscle by all fiber types
What is OBLA
The onset of blood lactate accumulation
* The speed at which blood lactate reaches 4 mmol/L
* Gradually raise in anaerobic energy generation
* Measurements of the lactate breakpoint → the velocity at which blood lactate begins to accumulate in the blood
Muscular responses to training
Increased oxygen uptake Metabolic changes
Increased efficiency
Skeletal responses to training
Bone growth and remodelling Cartilage, tendons, and ligaments
Respiratory responses to training
Ventilation
Cardiovascular responses to training
Changes in heart rate
Increased efficiency
What is fatigue
Fatigue is the inability to continue to exercise et all or the inability to maintain the current intensity of exercise but with the possibility to continue at low intensity.
