Degree: Master of Science Abstract: Background: It is well known that exercise can improve glycemic control in individuals with type 2 diabetes (T2D). However, the glycemic response to exercise is highly variable. One of the primary causes of variability in response to a single bout of exercise may be timing in relation to meals. The timing of exercise has been shown to affect the glycemic response to subsequent meals but there is currently no consensus on the optimal time for exercise in individuals with T2D. Previous results from the Exercise, Physical Activity and Diabetes Glucose Monitoring (E-PAraDiGM) protocol found no significant differences in 24-hour glucose when exercise was performed 3-4 hours after lunch. The present study is a follow-up to the E-PAraDiGM protocol to determine if this result was due to the timing of the exercise. Methods: Fourteen individuals with T2D were recruited and wore continuous glucose monitors (CGM) for 12 days. They completed the following four conditions: i. exercise in the morning before breakfast (MorEX) ii. exercise 3-4 hours after lunch (AftEX), iii. exercise 30 minutes after dinner (EveEX), and iv. seated control (CON). The exercise and control interventions were separated by 48-hour washout periods. Each participant completed the conditions according to a randomized, crossover design. The exercise protocol consisted of 50 minutes of walking at 5.0 km/hr and 0.5% incline which is approximately equivalent to 3.5 metabolic equivalents (METS) . Standardized meals were provided for two days in each condition. Macronutrient profile was based on Diabetes Canada Guidelines of ~55% carbohydrate, ~30% fat, and ~15% protein. Results: Eight males and six females were included in the analysis. On average they were 65 ±9.0 years old and had T2D for 10.5 ±6.8 years. The mean A1C for participants was 6.7 ±0.6 percent. Thirteen participants were treated with oral hypoglycemic medications and one controlled their diabetes through diet and exercise. Mean glucose in the four conditions was 7.4 ±0.7mmol/L, 7.3 ±0.7mmol/L, 7.5 ±0.8mmol/L and 7.5 ±0.7mmol/L in the MorEX, AftEX, EveEX and CON conditions respectively. Overall, there was no significant difference in mean 24-hour glucose among the four conditions (P=0.55). When T-tests were performed among the three exercise conditions, no significant difference was found between MorEX, AftEX, EveEX. Conclusion: Fifty minutes of walking at three different times of day did not lower 24-hour glucose concentrations in people with T2D. These findings are not consistent with other studies of this nature. The reasons why exercise was not effective at lowering glucose are unclear at this time.