Examining the Acute Glycemic Effects of Different Types of Structured Exercise Sessions in Type 1 Diabetes in a Real-World Setting: The Type 1 Diabetes and Exercise Initiative (T1DEXI)

Abstract

OBJECTIVE Maintenance of glycemic control during and after exercise remains a major challenge for individuals with type 1 diabetes. Glycemic responses to exercise may differ by exercise type (aerobic, interval, or resistance), and the effect of activity type on glycemic control after exercise remains unclear. RESEARCH DESIGN AND METHODS The Type 1 Diabetes Exercise Initiative (T1DEXI) was a real-world study of at-home exercise. Adult participants were randomly assigned to complete six structured aerobic, interval, or resistance exercise sessions over 4 weeks. Participants self-reported study and nonstudy exercise, food intake, and insulin dosing (multiple daily injection [MDI] users) using a custom smart phone application and provided pump (pump users), heart rate, and continuous glucose monitoring data. RESULTS A total of 497 adults with type 1 diabetes (mean age ± SD 37 ± 14 years; mean HbA1c ± SD 6.6 ± 0.8% [49 ± 8.7 mmol/mol]) assigned to structured aerobic (n = 162), interval (n = 165), or resistance (n = 170) exercise were analyzed. The mean (± SD) change in glucose during assigned exercise was −18 ± 39, −14 ± 32, and −9 ± 36 mg/dL for aerobic, interval, and resistance, respectively (P < 0.001), with similar results for closed-loop, standard pump, and MDI users. Time in range 70–180 mg/dL (3.9–10.0 mmol/L) was higher during the 24 h after study exercise when compared with days without exercise (mean ± SD 76 ± 20% vs. 70 ± 23%; P < 0.001). CONCLUSIONS Adults with type 1 diabetes experienced the largest drop in glucose level with aerobic exercise, followed by interval and resistance exercise, regardless of insulin delivery modality. Even in adults with well-controlled type 1 diabetes, days with structured exercise sessions contributed to clinically meaningful improvement in glucose time in range but may have slightly increased time below range.

Daily unstructured physical activity affects mean glucose, occurrence of hypoglycaemia and glucose variability in people with type 1 diabetes

“…The association between unstructured physical activity versus mean glucose concentration and risk of hypoglycaemia during the subsequent night was largely independent of the time of the day at which physical activity was performed (early‐day vs. late‐day). Together, these results may indicate that, in addition to the widely known association between structured MVPA and glucose control, 2,11 unstructured physical activities, even those performed at low intensity, also affect glucose control.…”

“…Because structured physical activities, also called sports activities, may cause substantial glycaemic disturbances in people with type 1 diabetes, specific management strategies are advised and used. [1][2][3][4] Little is known about glycaemic responses to daily unstructured physical activities, such as gardening, household maintenance and snow shovelling. 5 The daily amount of unstructured physical activity is highly variable within individuals and not reliably assessed by questionnaires.…”

Impact of a 4‐week intensive track and field training intervention on glycaemia in adolescents with type 1 diabetes: The ChilDFiT1 study

“…In line with the ChilDFiT1 results, Riddell et al showed that the TIR in adults with T1D is higher on exercise days than on sedentary days 41,42 . Likewise, Gal et al were able to show this for children and adolescents: higher activity levels in 9‐17 year‐old participants with T1D were associated with better TIR ( P < .001), without being linked to higher TBR 11 .…”

“…In line with the ChilDFiT1 results, Riddell et al showed that the TIR in adults with T1D is higher on exercise days than on sedentary days. 41,42 Likewise, Gal et al were able to show this for children and adolescents: higher activity levels in 9-17 year-old participants with T1D were associated with better TIR (P < .001), without being linked to higher TBR. 11 Overall, the current research along with the ChilD-FiT1 results show that adults as well as adolescents with properly guided assistance and the appropriate level of knowledge can participate in exercise without fear.…”

Publicly Available Data Set Including Continuous Glucose Monitoring Data

“…Another noteworthy endeavor is the Type 1 Diabetes and Exercise Initiative (T1DEXI), 5 which investigates the immediate glycemic effects of different types of structured exercise sessions in individuals with type 1 diabetes within a real-world context. This initiative is sponsored by the Helmsley Charitable Trust in collaboration with Vivli, an independent nonprofit organization dedicated to promoting, coordinating, and facilitating the sharing of clinical research data worldwide through a global data platform.…”