Metabolism In The Human Body

Introduction - 600

Metabolism is the ability of the body to synthesise, use, and regulate energy stores (Miller, 2012). Metabolism can also be referred to as energy expenditure as it includes the building up and breaking down of biological compounds. This is essential in exercise as the constant need for more energy requires the metabolism of Adenosine Triphosphate (ATP), which is the final biochemical carrier of energy. There are three main metabolic pathways to produce energy, the ATP-PCr, Glycolytic, and Oxidative systems (Knuttgen, 2000). The ATP-PCr and Glycolytic systems are both part of anaerobic metabolism, while the oxidative system is an example of aerobic metabolism. Therefore this limits as to when each system is used due to the

The atmospheric pressure was noted with a Barometer, (Diplex, Germany) and a Weather Station (BAA913HG, Oregon Scientific, UK) was used to record humidity, ambient temperature, O2, and CO2 readings. All tests were performed on a cycle ergometer (874E, Monark, Sweden). The height of the seat and the handle bars were determined on the first graded exercise test, and remained the same for all tests. The submaximal graded exercise test consisted of a wattage of 60 for the start and continuous increment increases of 60W every 4 minutes until 180W.

Each participant was fitted with a wireless chest strap telemetry system (FS1, Polar, Finland) to monitor their heart rate throughout the test. They were also required to wear a mouth piece attached to a set of Douglas Bags (Cranlea, UK) to collect all expired air throughout the test. A dry gas meter (Harvard, UK) was used to measure the volume and temperature of the gas, and a gas analyser (5200, Servomex, UK) was used to determine O2 and CO2 levels. The timing in this study was determined with a Stopwatch (DT100, Digi Lap,

This is evident from the results collected as figure 1 clearly shows the increase of CHO consumption with the increase of wattage. The main results for this are that at rest the mean CHO consumption (kcal) was 0.6, at 60W this had increased to 2.0, at 120W it was 3.7, and finally at 180W it was 7.3. This increase can be attributed to fact that the sub maximal test the participants undertook became anaerobic with the increase of wattage. This can be supported with the RER values collected. An RER value of 0.85 indicates that the mixture of substrates being metabolised is around 50% fat and 50% CHO. The values for rest and 60W are around this value with 0.81 and 0.87, however when the wattage is increased again the RER values jump up to 0.91 at 120W, and 0.94 at 180W. This suggests that the substrate percentage is now leaning more towards CHO consumption and a RER value of >1.00 indicates 100% energy being produced from CHO under anaerobic