A mixed-method approach to low energy availability in elite track cyclists

Relative Energy Deficiency in Sport (RED-S) is a complex condition that has a range of health consequences involving, but not limited to, metabolic, immune, and reproductive function, and psychological health. Low energy availability (LEA) is the underlying cause of RED-S. LEA can be defined as limited dietary energy available for normal physiological and metabolic functions, after accounting for energy expended from exercise training. Quantitative and qualitative methodological approaches have been used to investigate LEA (Chapter 2). However, most research methods and findings on LEA are typically conducted and interpreted in isolation. LEA is a complex and integrated syndrome, yet the research that brings together the dialogue between quantitative and qualitative findings is limited. Therefore, the purpose of the thesis was to expand on RED-S by using a mixed-method approach and gain further understandings of the complexity of LEA (Chapter 3). The thesis is divided into seven chapters that incorporate published and unpublished manuscripts. A mixed-method approach was used within an elite athletic cohort to understand the nuances and the relationship between the quantitative physiological and qualitative socio-psychological aspects of LEA (Chapter 4). Data were collected at two time points (T₁ and T₂, respectively), from 15 (10 female, 5 male) members of the Cycling New Zealand (CNZ) elite endurance track cycling high-performance programme. Physiological data were captured from blood (hormonal and metabolic markers), metabolic testing, energy availability status, and bone health at both time points. Socio-psychological data were captured via semi-structured interviews from a sub-set of the cyclists, following the physiological data at T₁. The interviews covered topics in the context of RED-S such as menstruation, body image, nutrition, and injury/illness. These topics were chosen as they had been previously identified in the literature as key markers of LEA. Also