ANZCTR - Registration

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Trial registered on ANZCTR

Registration number

ACTRN12625000716460

Ethics application status

Approved

Date submitted

12/06/2025

Date registered

7/07/2025

Date last updated

7/07/2025

Date data sharing statement initially provided

7/07/2025

Type of registration

Prospectively registered

Titles & IDs

Public title

Investigating the effect of whey protein ingestion on post-exercise hypoglycaemia following resistance exercise in people with type 1 diabetes.

Scientific title

Investigating the effect of whey protein ingestion on post-exercise hypoglycaemia following resistance exercise in people with type 1 diabetes.

Secondary ID [1]

None

Universal Trial Number (UTN)

Trial acronym

Linked study record

This study is a follow-up study related to ACTRN12624001096549.

Health condition

Health condition(s) or problem(s) studied:

Type 1 Diabetes

Condition category

Condition code

Metabolic and Endocrine

Diabetes

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

For all intervention sessions pre-exercise preparations will involve a standardised meal between 30-60g of carbohydrates to be consumed roughly 4 hours prior to exercise, with standard insulin bolus regimens followed. The temporary target on the participant's device will also be set 90 minutes before exercise commencement.

All intervention resistance sessions will be conducted with the first set being 40% of the participant's three repetition maximum (3RM) and the next 3 sets will be conducted at 80% of 3RM with all reps performed at a roughly 2 second concentric and 2 second eccentric cadence. At screening individuals will participate in a 3RM strength test to determine the appropriate testing value.

The main portion of the study will involve the four resistance exercise sessions which will completed by all study participants, each with varying post-exercise requirements after a 40 minute resistance exercise session and then a meal consumed 180 minutes after the completion of the resistance exercise The sessions will be completed in a randomised order for each participant. Session A, will be the control session in which just the exercise and then resultant meal will be consumed. Session B be will require the whey protein drink be consumed within 30 minutes post exercise completion. Session C will require the whey protein drink to be consumed with the post-exercise standard meal. Session D will mimic current 'best-practice' guidelines, with a 25% insulin reduction being administered at the time of the post-exercise meal.

The sessions will be conducted one on one, with a study investigator and a study doctor and/or study exercise physiologist present. Sessions will be scheduled when participants are free, There will be no scheduled days for the sessions and sessions will be scheduled around when participants are free.

The optional aerobic exercise sessions will choose to undertake in two additional bouts of moderate intensity exercise (MIE). Individuals will both complete session E and one of sessions Fi or Fii. Session E will involve a 40 minute MIE aerobic session with the standardised meal 180 minutes post exercise. Sessions Fi and Fii will involve the 40 min standard exercise session with a whey protein drink during the 30 minute interval post-exercise or at the time of the meal for sessions Fi and Fii respectively.

The first 20 participants who opt-in to undertake the optional aerobic exercise sessions will complete 40 minutes of moderate intensity (50% of their VO2 max) aerobic exercise sessions conducted on a cycle ergometer (exercise bike). At screening individuals will participate in a VO2 max session to discover the appropriate testing value. These sessions will be conducted by a study investigator and study doctor and/or study exercise physiologist.

The meal components will be specific to each participant based on their standard recommendation macronutrient and caloric intake, as determined by their clinician or diabetes educator. There will be differences between the participants as their standardised meal will be based on individual factors such as; sex, age, average physical activity, etc. As long as the insulin bolus will be administered before the meal the duration of meal consumption does not need to be within a specific time frame rather should be as per standard eating habits. It will be ensured that on the days of these exercise studies that each individual is consistent with their meal caloric and macronutrient composition.

If during the exercise sessions the sensor glucose levels drop below 7.0 mmol/L, 10g of carbohydrate will be consumed by the participant and a 15 minute break will be given to allow for a rise in blood glucose. This can be conducted up to three times during the exercise session (totalling 30g of carbohydrate) before the exercise session will be re-scheduled.

There must be at least 48 hours between all sessions, including the period between an individual completes the aerobic and resistance exercise sessions.

Intervention code [1]

Treatment: Other

Comparator / control treatment

Session A, will be the control session in which just the exercise and then resultant meal and 250ml drink of water will be consumed.

Control group

Active

Outcomes

Primary outcome [1]

The primary outcome is the total number of hypoglycemic episodes recorded on CGM in the 4-hours following the post-exercise standardised meal.

Timepoint [1]

4 hours following the post-exercise standardised meal (t = 220min) to (t = 460min) for each exercise session.

Secondary outcome [1]

Mean glucose on continuous glucose monitor.

Timepoint [1]