Exercise Timing and Gestational Diabetes

Mean, peak and nadir 24 hour daily glucose, glycemic variability, fasting glucose, time spent in hyperglycemia (>10mmol/l), and time spent in hypoglycemia (<3.5mmol/l). These values will be compared between pregnant individuals diagnosed with gestational, pre- or Type 2 diabetes, and healthy pregnant individuals. High postprandial glucose level indicates poor blood glucose control.

All participants will be asked to wear an accelerometer (Actigraph wGT3X-BT Monitor, Actigraph LLC) for fourteen consecutive days to record 24-hour physical activity (min/d). This information will be collected to determine overall physical activity and movement behaviours (including light, moderate and vigorous activity intensity).

All participants will be asked to wear an accelerometer (Actigraph wGT3X-BT Monitor, Actigraph LLC) for fourteen consecutive nights to record 24-hour physical activity (min/d). This information will be collected to determine total sleep time (min/day)

Participants will be lent a heart rate monitor chest strap and watch (Polar) to wear during their walking sessions to confirm they are in the prescribed intensity range. The chest strap is worn around the chest with the sensor placed just inferior to the sternum. It wirelessly connects to the watch which displays their heart rate in beats per minute (BPM). Participants are asked to maintain a heart rate 0f 101 - 146 bpm to represent moderate intensity physical activity.

Health history (personal and familial) may affect the results of variables assessed within this study. Participants will be asked about their age (years), height (cm) and weight) (kg). They will also be asked about their pregnancy health and any complications that should be noted. The over all purpose of this questionnaire is to allow us describe the type of participant recruited to this study. This questionnaire can be submitted online via Redcap, or by hard copy (if requested).

We will use a questionnaire prior to the intervention to estimate participants physical activity level using the Pregnancy Physical Activity Questionnaire. Total activity time will be computed (min/day) from this. This questionnaire can be submitted online via Redcap, or by hard copy (if requested).

We will use a questionnaire prior to the intervention to estimate participants sleep quality using the Pittsburgh Sleep Quality Index. This questionnaire can be submitted online via Redcap, or by hard copy (if requested). Each component is scored on a scale of 0-3 with higher values representing greater sleep dysfunction.

Diet may affect the results of variables assessed within this study. We will ask participants to keep a hand written diary log for the duration of the study about the type and amount (grams) of food intake they are consuming.

Data on maternal complications if any, will be recorded from medical notes. This may include although not limited to diagnosis of pre-eclampsia, hypertension in pregnancy, caesarean section, birth complications, instrumental delivery, blood loss, and length of labour. These outcomes will be collected as categorical variables with 'yes ' or 'no' as an answer.

Data on infant outcomes will be recorded from medical notes. This may include although not limited to weeks of gestation at birth, birth weight, hypoglycemia at birth, admission to NICU, breastfeeding status, infant mortality, and 2-month development. These outcomes will be collected as categorical variables with 'yes ' or 'no' as an answer.

Apgar scores will be collected from medical notes. An apgar score