August 7, A Review of Anaerobic versus Aerobic Conditioning One of the biggest trends in conditioning is a focus on high intensity training protocols for cardiovascular conditioning and weight management versus the traditional focus on steady state low — moderate intensity training protocols.
Piercy, in Equine Exercise PhysiologyMuscular responses to exercise When aerobic metabolism can meet energy Lab aerobic and anaerobic metabolism during submaximal exerciseoxygen uptake correlates with increasing speed.
However, the slope of the linear relationship may vary according to the load, incline, track surface, and ambient temperature. At a certain point, energy demand outstrips oxygen uptake and the shortfall must be met by anaerobic metabolism. Muscle fatigue may occur during either aerobic or anaerobic exercise; in the following sections, we consider the major metabolic changes that occur within muscle that are believed to contribute to the development of fatigue.
Aerobic exercise Muscle and liver glycogenolysis starts to occur soon after the start of aerobic exercise.
Glucose derived from the liver is subsequently transported into myofibers to join the glycolytic cascade via glucosephosphate formation see Fig. This reliance on glucose derived mainly from the liver results in an early sparing of muscle glycogen. The overall effect is that muscle glycogenolysis declines over time during aerobic exercise, whereas FFA oxidation increases.
Although lipids are the predominant fuel utilized during prolonged submaximal exercise, fatigue occurs long before the complete utilization of lipid stores. At submaximal workloads, fatigue has been associated with intramuscular glycogen depletion Fig.
During prolonged activity, glycogen depletion patterns occur in parallel with the progressive recruitment of fiber types, i. This depletion at least during submaximal long term exercise affects the acid-soluble form of glycogen macroglycogen to a greater extent than the acid-insoluble form proglycogen.
Muscular fatigue then does not occur at the same time in all fibers but in a progressive manner that results in gradual compromise to performance. Following exercise, glycogen replenishment first the proglycogen pool, then macroglycogen occurs in the reverse order i.
The apparently slower rate of glycogen synthesis after exercise in horses in comparison with other species may reflect the lack of increased GLUT-4 expression reported by some authors after grain feeding and exercise.
Nevertheless, strenuous exercise causes an increase in total content of GLUT-4 protein in skeletal muscle: However, although glycogen depletion appears to play a major role in fatigue onset during aerobic exercise, a variety of other factors are also implicated, including AMP deamination, hyperthermia, dehydration, electrolyte depletion, and lack of motivation.
The onset of fatigue itself may be hard to assess objectively but recent evidence suggests that electromyography may prove useful in the experimental setting.
Aerobic exercise in the horse is also associated with decreased serum branched-chain amino acid concentrations, but this decrease does not correspond to a measurable increase in total muscle amino acid concentrations.
Further research is, however, required to evaluate amino acid metabolism better during exercise, as it appears to play an important role in both performance and recovery after exercise. Additionally, increased oxygen utilization during exercise results in proportional increases in reactive oxygen species ROS production, potentially causing oxidative stress, a state where increased generation of ROS overwhelms body antioxidant protection, resulting in lipid, protein, and DNA damage.
Information on exercise-induced oxidative stress in horses is limited. In response to oxidative stress, cells synthesize heat shock proteins in protective homeostatic responses.
However, a moderate bout of aerobic exercise in horses, though associated with mild muscle damage and potentially mild oxidative stress, failed to induce this defense mechanism, perhaps because acidosis, rather than energy depletion, appears to be the instigator of this response after long-term moderate-intensity exercise.
Anaerobic exercise The functional demands imposed by high-intensity exercise require the recruitment of most motor units within a given muscle, while intramuscular glycogen and blood glucose act as the predominant fuels to replenish ATP during anaerobic glycolysis. Some ATP is derived from the deamination of ade-nosine nucleotides; however, in contrast to aerobic metabolism, there is relatively little reliance on FFA oxidation.
In recent years further research has confirmed many previous observations and provided new insight on mechanisms underlying the onset of fatigue. Lactate accumulation and pH decline Limitations imposed by oxidative metabolism result in more pyruvate the end-product of glycolysis being converted to lactate rather than acetyl-CoA; in the process, NAD is used to regenerate more ATP.
As a consequence, muscle lactate concentrations increase during anaerobic exercise. This rise is correlated with the proportion of type II fibers within muscles. Initially, intracellular lactate accumulation is removed from the cell by active transport into the blood Figs 2.
Muscle pH may decline to as low as 6. Low pH also leads to dysfunction of the excitation—contraction coupling mechanism, through impairment of the SR calcium release via RYR1 channels, and decreased reuptake of calcium into the SR during relaxation.are capable of both aerobic and anaerobic metabolism They metabolize as aerobes if oxygen is present and as anaerobes when oxygen is not present.
Cellular Respiration: Aerobic vs. Anaerobic Respiration is a process which happens inside the cells in which carbohydrates, especially glucose, is broken down for . Table 1, at the bottom of this article, provides a breakdown of the aerobic and anaerobic components of selected track and field events and sports.
Fat as a fuel source for the aerobic energy system Although carbohydrate is the body’s preferred source of fuel during activity, fat also supplies energy.
Prokaryotes may perform aerobic (oxygen-requiring) or anaerobic (non-oxygen-based) metabolism, and some can switch between these modes. Some prokaryotes have special enzymes and pathways that let them metabolize nitrogen- or sulfur-containing compounds.
Jan 03, · BIO$$Vertebrate$Physiology$ Lab$3:$Oxygen$and$Aerobic$Metabolism$ the$volume$data.$If$the$baseline$on$the$top$graph$has$drifted,$use$the$Baseline$Adjustment. LABORATORY EXPLORATION Anaerobic Metabolism in Yeast oxygen via the process known as aerobic respiration.
Under conditions where oxygen your lab instructor will encourage the various teams to discuss their experiments well before lab begins.