Metabolic Responses to Supramaximal Exercise
The objective of the present study is to assess, determine and understand the various metabolic responses and functions of the body towards supramaximal exercise through extensive literature survey and study of the previous available research conducted in this area.
Energy during exercise is supplied by two metabolic pathways, aerobic and anaerobic pathways. Supramaximal exercises are highly stressed exercises which are majorly performed for body and muscle building and also for keeping one’s body and muscles fit. The supramaximal exercises comprises of exercises such as running on roads or treadmills, weight-lifting, rigorous cycling, martial arts etc. Such exercises are exhaustive and lead to anaerobic metabolic responses in the body. The most common types of metabolic responses of such exercise comprises of various types of hormonal responses such as changes in levels adrenaline, nor-adrenaline, cortisol, insulin, growth hormone etc. Other important response includes change in levels of glucose and oxygen demand. Glycolysis and Glucogenolysis are the metabolic process which is involved during exercises. Also, production of lactic acid for energy generation is the most important metabolic response observed in case of supramaximal exercise. Lactate can be used as source of fuel by the exercising muscles and converting them to acetyl-CoA which enters Krebs cycle. The lactate produced in the muscles can be send to liver where it is converted to glucose which is then again transported to the muscles to be used as fuel (Powers & Howley, 2009).
Study of the metabolic responses towards supramaximal exercises is possible by conducting experiments on group of healthy individuals and studying them through applying various scientific, medical and mathematical methods. The physical characteristics of the individuals such as age, bodymass and exercise habits are studied and always recorded. The first step in such experiments is to record the time spend on such exercises, measure the different hormone levels by testing the blood of each individuals, measure the blood glucose level, measure the heart rate, blood pressure and normal physical conditions of such experimental individuals prior and after the experiments conditions. Such experiments should be conducted only on healthy individauls to avoid any experimental error.
Supramaximal exercise is a stressor and it has various impacts on body’s physiology and metabolism. In one of the research work, supramaximal exercise was associated with blood glucose, insulin and lactate concentrations (Roy et al., 1991). An exercise task of running on treadmill was conducted in 10 male physical education students in order to test the metabolic and hormonal responses to short-term supramaximal exercise. Three trials were studied (single oral doses of 100 mg bupranolol, 100 mg meloprolol and placebo condition) and in all three trials, at the end of exercise, levels of hormone adrenaline and nor-adrenaline were elevated, levels of glucose and lactate also increased. There was also rise in insulin incase of control and metoprolol but not in bupranolol trials. Delay in increase of growth hormone was also observed (Schnabel et al., 1984). One study shows supramaximal exercise produces significant and substantial increase in levels of blood cortisol (Behr et al., 2009). In one study where two group of subjects one being national karate team and another being international karate team were studied for maximal accumulated oxygen deficit (MAOD). It was observed in the study that there were higher concentrations of metabolites like ammonia and lactate in both the groups after the karate performance (Ravier et al., 2005).
The internal environment of the human body maintains a constant homeostasis. Any stressor or over-activity alters the internal homeostasis of the body. The changes are observed in the external as well as the internal biological processes such as in the physiology and metabolism of the body. During supramaximal exercise, the oxygen consumption attains its maximal value within 20-30 seconds (Prampero & Ferretti, 1999). The most important metabolic response of supramaximal exercise which is a kind of stressor to the body is the production of lactic acid.