Repository logo
 

Acute, Short- and Medium-Term Cardiometabolic Outcomes of High-Intensity Interval Training Compared to Moderate-Intensity Continuous Training in Men Living With Type 2 Diabetes

Files

Whole thesis(2.73 MB)

Date

2018

Authors

Supervisor

Harris, Nigel
Dalleck, Lance
Zinn, Carryn
Rush, Elaine

Item type

Thesis

Degree name

Doctor of Philosophy

Journal Title

Journal ISSN

Volume Title

Publisher

Auckland University of Technology

Abstract

Type 2 diabetes (T2D) is a progressive disease, requiring the adoption of behaviours to help delay the progression of life-threatening diabetic complications. Literature indicates high-intensity interval training (HIIT) as a suitable option, in the short-term, for pursuing improved cardiometabolic health in individuals with T2D. However, no randomised controlled trial (RCT) has been conducted using HIIT combined with resistance training (HIIT+RT) to determine the glycaemic control and markers of macro- and microvascular complication effects in people with T2D - nor compared the durability of such effects. The study aimed to compare the acute, short- and medium-term effects of HIIT+RT to moderate-intensity continuous training (MICT+RT), on glucose control and diabetic complication markers. My study recruited T2D men about to exercise in a real-world setting and, firstly, compared the acute physiological responses (APR) to a HIIT+RT or MICT+RT session; secondly, compared the short-term effects of a 12-week structured intervention of either HIIT+RT or MICT+RT on glucose control and complication markers; and finally, compared the medium-term durability of benefits from such training interventions after a 6-month follow-up. Twenty-three men having moderate-duration T2D presented as sedentary, class II obese (≥35.0 kg/m2), and while taking prescribed medications had elevated glycated haemoglobin (HbA1c) and were pre-hypertensive. Participants performed supervised MICT+RT (progressing to 26-min at 55% maximum estimated workload [eWLmax]) or HIIT+RT (progressing to two variations in which twelve 1-min bouts at 95% eWLmax interspersed with 1-min recovery bouts, alternated with eight 30-sec bouts at 120% eWLmax interspersed with 2:15 min recovery bouts). In assessing the APR, peak heart rate, workload and perceived exertion were higher for HIIT+RT (P=0.04, P<0.001 and P<0.001, respectively), although energy expenditure and peak systolic and diastolic blood pressure responses were similar between groups (P=0.47, P=0.71, P=0.56, respectively). The acute blood glucose responses were similar across all time points (P>0.05). However, there were acute exaggerated responses (using exercise termination indicators) reported to a similar extent (P=0.39) for both MICT+RT (64%) and HIIT+RT (36%) participants. To account for fixed and random effects within the study sample, mixed-effect models were used to determine significance of change and to evaluate group*time interactions. Beyond improvements in aerobic capacity (P<0.001) for both groups, both training modalities elicited similar group*time interactions (P>0.05) while experiencing benefits for HbA1c (P=0.01), subcutaneous adiposity (P<0.001) and heart rate variability (P=0.02) during the 12-week intervention. Adiposity (P<0.001) and aerobic capacity (P<0.001) were significantly maintained in both groups at the 6-month follow-up. In addition, during the interventions, SPs in both MICT+RT and HIIT+RT experienced favourable reductions in medication usage. The study reported inter-individual variability of change, exaggerated physiological responses and the precautionary respite afforded to the participants. The findings appear to indicate that, over the short- or medium-term, HIIT+RT is not superior to MICT+RT for the improvements experienced in both groups for HbA1c, subcutaneous adiposity and heart rate variability. This indicates that current guidelines are efficacious and exercise professionals can be confident including MICT+RT (cognisant of appropriate supervision) into their training prescriptions to help men with T2D reduce the progression of macro- and microvascular complication markers.

Description

Keywords

Macrovascular, Microvascular, Moderate intensity continuous training (MICT), High intensity interval training, Resistance training, Type 2 diabetes, Acute effects, Training durability

Source

DOI

Publisher's version

Rights statement

Permanent link

https://hdl.handle.net/10292/11577

Collections

Doctoral Theses