<b>Objective:</b> To
study the effect of 12 weeks of high-intensity interval training (HIIT) on glycemic
control in adults with type 1 diabetes with overweight or obesity.
<p> </p>
<p><b>Research
Design and Methods:</b> Thirty inactive adults with type 1
diabetes who had BMI≥25kg/m<sup>2</sup> and HbA1c≥7.5% were randomized to 12
weeks of either: HIIT exercise intervention consisting of 4x4 minutes HIIT
(85-95% HRpeak) performed thrice weekly, or usual care control. In a partial
cross-over design, the control group subsequently performed the 12-week HIIT intervention.
The primary endpoint was the change in HbA1c from baseline to 12 weeks. Glycemic
and cardiometabolic outcomes were measured at 0, 12, and 24 weeks.</p>
<p> </p>
<p><b>Results:</b>
Participants were aged 44±10 years, with diabetes duration 19±11 years, and BMI
30.1±3.1 kg/m<sup>2</sup>.<sup> </sup>HbA1c decreased from 8.63 ± 0.66% at
baseline to 8.10 ± 1.04% at 12 weeks in the HIIT intervention group (p=0.01),
however this change was not significantly different to the control group (HIIT
-0.53 ± 0.61%, control -0.14 ± 0.48%, p=0.08). In participants who undertook at
least 50% of the prescribed HIIT intervention, the HbA1c reduction was
significantly greater than control (HIIT -0.64 ± 0.64% (n=9), control -0.14 ±
0.48% (n=15), p=0.04). There were no differences in insulin dose, hypoglycemia
on continuous glucose monitoring, blood pressure, blood lipids, body weight or
body composition between groups. </p>
<p> </p>
<p><b>Conclusions:</b> <a>Overall, there was no significant reduction in HbA1c with a
12-week HIIT intervention in adults with type 1 diabetes. However glycaemic
control may improve for people who undertake HIIT with greater adherence.</a></p>
High-Intensity Interval Training Improves Aerobic Capacity Without a Detrimental Decline in Blood Glucose in People With Type 1 Diabetes