Does Exercise Timing Affect 24-Hour Glucose Concentrations in Adults With Type 2 Diabetes? A Follow Up to the Exercise-Physical Activity and Diabetes Glucose Monitoring Study.

OBJECTIVES: It is well known that exercise can improve the glycemic profile in individuals with type 2 diabetes (T2D). However, the optimal timing of exercise is often debated. Our aim in this study was to compare the effects of exercise performed at different times of the day and different timing in relation to meals on 24-hour glucose profiles in people with T2D. METHODS: Fourteen individuals with T2D were recruited and wore continuous glucose monitors for 12 days. During the 12 days, participants completed 4 conditions according to a randomized, crossover design: i) morning (fasting) exercise (MorEx), ii) afternoon exercise (AftEx), iii) evening exercise (EveEx) and iv) seated control. Exercise consisted of 50 minutes of walking at 5.0 km/h. RESULTS: Eight men and 6 women (age, 65±9.0 years; T2D duration, 10.5±6.8 years; mean glycated hemoglobin, 6.7±0.6%) were included in the analysis. Mean 24-hour continuously monitored glucose was 7.4±0.7 mmol/L, 7.3±0.7 mmol/L, 7.5±0.8 mmol/L and 7.5±0.7 mmol/L in the MorEx, AftEx, EveEx and control conditions, respectively, with no significant differences among the 4 conditions (p=0.55). MorEx had a lower respiratory exchange ratio compared with AftEx and EveEx (p<0.01). The decrease in glucose during exercise was less pronounced for MorEx compared with AftEx (p<0.05). CONCLUSIONS: Fifty minutes of walking at 3 different times of day and at different timing in relation to meals did not lower 24-hour glucose concentrations in people with T2D. The reasons why exercise was not effective at lowering glucose remain unclear.

Minimal effect of walking before dinner on glycemic responses in type 2 diabetes: outcomes from the multi-site E-PAraDiGM study.

AIM: To examine the effect of walking before dinner on 24-h glycemic control in individuals with type 2 diabetes using the standardized multi-site Exercise-Physical Activity and Diabetes Glucose Monitoring (E-PAraDiGM) Protocol. METHODS: Eighty participants were studied under two conditions (exercise vs. non-exercise control) separated by 72 h in a randomized crossover design. Each condition lasted 2 days during which standardized meals were provided. Exercise consisted of 50 min of treadmill walking at 5.0 km/h before the evening meal, while control involved 50 min of sitting. The primary outcome measure was mean glucose during the 24-h period following exercise (or sitting) measured by continuous glucose monitoring. RESULTS: Of the 80 participants who were initially randomized, 73 completed both exercise and control. Sixty-three participants [29 males, 34 females; age = 64 ± 8 years, body mass index = 30.5 ± 6.5 kg/m2 and HbA1c = 51 ± 8 mmol/mol (6.8 ± 0.7%), mean ± SD] complied with the standardized diets and had complete continuous glucose monitoring data. Exercise did not affect mean 24-h glucose compared to control (0.03 mmol/L; 95% CI - 0.17, 0.22, P = 0.778) but individual differences between conditions ranged from - 2.8 to +1.8 mmol/L. Exercise did not affect fasting glucose, postprandial glucose or glucose variability. Glucose concentrations measured by continuous glucose monitoring were reduced during the 50 min of walking in exercise compared to sitting in control (- 1.56 mmol/L; 95% CI - 2.18, - 0.95, p < 0.001). CONCLUSION: Contrary to previous acute exercise studies, 50 min of walking before dinner in the E-PAraDiGM protocol did not affect 24-h glucose profiles. However, highly heterogeneous responses to exercise were observed. TRIAL REGISTRATION: NCT02834689.

We Can Work (It) Out Together: Type 1 Diabetes Boot Camp for Adult Patients and Providers Improves Exercise Self-Efficacy.

OBJECTIVES: This project aimed to use education sessions and exercise classes to improve exercise self-efficacy in individuals with type 1 diabetes and in diabetes care providers (DCPs). METHODS: We recruited 12 adults with type 1 diabetes and 12 DCPs who participated in 4 weekly group sessions to learn about exercise physiology and to experience various exercise types. We provided participants who had type 1 diabetes with real-time continuous glucose monitors and heart rate monitors to enhance experiential learning. Both groups completed questionnaires before and after the study to assess confidence concerning exercise. Following the study, focus groups assessed the impact of the study on knowledge and self-efficacy. RESULTS: There was an improvement in DCPs' attitudes toward exercise (p=0.004). DCPs' confidence in providing clients with advice regarding the time, type and intensity of exercise (p=0.005) and strategies for overcoming barriers to exercise (p=0.016) improved significantly. We found no significant changes in results in the questionnaires of participants with type 1 diabetes. Focus group analysis suggested that the study improved awareness of the importance of exercise as well as knowledge about the effects of exercise in type 1 diabetes by both DCPs and participants. Continuous glucose monitor use alleviated fear of hypoglycemia by participants with type 1 diabetes. CONCLUSIONS: These findings suggest that a 4-week education- and exercise-focused program improves DCPs' self-efficacy in providing exercise advice to patients. People with type 1 diabetes did not experience an improvement in exercise self-efficacy; however, the study supports the use of continuous glucose monitoring and the grouping of DCPs and individuals with type 1 diabetes to facilitate experiential learning.