The metabolic responses of high intensity intermittent exercise in healthy untrained adults

Sustaining a healthy body weight relies on maintaining energy balance. Energy balance describes the relative energy intake (dietary) to the energy expenditure (cellular energy and physical activity). In order to decrease adiposity, energy balance needs to be shifted negative, heightening energy expenditure so that it outweighs energy intake. The most malleable and cost effective method of energy balance manipulation is increasing physical activity. Diet and food intake can also be manipulated to reduce energy intake, however this can become quite costly and time consuming, particularly for those who are time poor and uneducated in healthy and low calorie foods. High intensity interval training (HIIT) has been shown to increase fat loss more effectively than continuous moderate intensity training (Tremblay et al., 1994; Trapp et al., 2008; Macpherson et al., 2011; Gremeaux et al., 2012), which is optimal for fat oxidation rates and was once considered the best exercise type employed to lose body fat. A recent study attributed this enigma to the rapid burst of intense exercise with the slight restorative effect of interspersed work and passive rest. Although the aforementioned studies were training studies, this study used single bouts of workload matched HIIE and moderate intensity, continuous exercise (CON) and found similar levels of fat utilisation between the two trials as well as significantly greater plasma and urine purine nucleotides post HIIE compared to CON, potentially resulting in greater energy loss. This thesis aims to measure metabolic profiles for a range of HIIE models to understand the mechanism and determine which may be best at inducing an energy deficit that can lead to elevating energy expenditure, hence more rapid reductions in fat mass observed with HIIT.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

Victoria University

Year dc:date.issued

2013

Author dc:creator

• Gerber, Tracey

• 1106 Human Movement and Sports Science
• College of Health and Biomedicine

Language dc:language

en