LABORATORY BASED CLIENT REPORT
Obesity is an ongoing issue and prevalence worldwide is constantly increasing (Cameron et al., 2003).
A study area of great interest is the relationship between weight loss or the loss of fat mass and exercise intensity. Metabolic function, energy sources and energy expenditure all have great influence on the success of weight loss.
For efficient metabolic function the human body requires an ongoing energy source. This energy source comes from the food that has been consumed. Metabolism refers to chemical reactions responsible for energy transfer within the body (Moffet, Moffet, & Schauf, 1993). Once food enters the body it must go through a series of chemical events in order to be converted to chemical energy ready to be utilised (McArdle, Katch & Katch, 2007).
As reported by Plowman and Smith (2011), the metabolic system has two main functions: anabolism and catabolism. Anabolism is a process in which energy is used to build tissues in the body whereas catabolism produces energy from the breakdown of foods and stores it in order to offer energy to the body when it is required.
The energy rich compound, Adenosine Triphosphate (ATP) is considered to be the most preferential agent for energy transfer (McArdle, Katch & Katch, 2007). It is the underlying molecule which powers all cellular processes. This compound is not transferred directly to cells from macronutrients but rather is harvested and funnelled (McArdle, Katch & Katch, 2007). This process which converts energy from food to ATP is called cellular respiration and it is divided into anaerobic (does not require oxygen) and aerobic (requires oxygen) elements (Plowman and Smith, 2011).
The main sources of energy are carbohydrates and fats. Carbohydrates are considered the preferential fuel for the human body because they supply energy to several tissues and demand less oxygen to be metabolised (McArdle et al., 2007). Fats are utilised to provide an energy-dense fuel to the body (Plowman and Smith, 2011).
McArdle et al. (2007) found that energy expenditure in exercise directly correlates with the duration and intensity of the activity. During low-intensity exercises the human body mainly uses fat stores (which are available in large scales in the body but take more time to be metabolised) as its main energy source. However, during high-intensity exercises, the human body requires energy much more rapidly. Consequently, carbohydrates are predominant in high intensity activity as they are metabolised faster than any other source of energy (Ekblom, 2001).
Previous literature have found low intensity, prolonged exercise to be the most efficient form of exercise for energy expenditure derived from fats although a definitive answer has not been reached (Tremblay, Simoneau, & Bouchard, 1994). High intensity activity however had been found to be effective in increasing oxygen consumption (VO2) and overall energy expenditure (Helgerud et al., 2007). 1
The aim of this study was to establish the most efficient training conditions in relation to intensity for successful fat metabolisation and fat loss. It was hypothesised that high intensity exercise would be the most efficient training condition in regards to weight loss due to greater energy expenditure. 2.0 Methods
2. 1 Participants
Twelve sport and exercise/exercise physiology students participated in this study. There were four females and 8 males involved. The participant’s demographic data was recorded including age (23.25±4.97 years), height (174.3±9.33 cm), (71.2±11.63 kg) and BMI ranging from (23.3±2.42 kg/m2). Training status of each participant was unknown however all subjects were apparently healthy and were assumed to be of moderate fitness level. Consent forms were distributed at the beginning of the semester’s practicals which covered this study.
This study was split into a two week experiment and required the following equipment for...
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