Alternative Physical Activity Strategies for Breast Cancer Survivors

University of Toronto24 enrolled

Overview

The primary aim of this study is to compare the acute glycemic effects of two novel, alternative physical activity (PA) strategies (dispersed post-meal PA, PA snacks) to a no PA condition and to exercise sessions representing the PA guidelines (standard 30-minute walking bout performed under fasting and under postprandial conditions and a standard 30-minute resistance training session) among sedentary breast cancer survivors who are currently receiving hormone therapies and age- and BMI-matched postmenopausal women without a history of cancer. The secondary aim is to determine whether the alternative PA strategies are acceptable and feasible in the free-living setting. An exploratory aim is to determine whether the outcomes differ between women with and without a history of breast cancer and use of aromatase inhibitors. The investigators hypothesize that: 1. Dispersed PA and PA snacks will result in greater reductions in 24-hour glucose and postprandial glucose compared to the no-PA baseline and similar reductions to a standard 30-minute bouts of walking; 2. The alternative PA strategies will be more feasible and have greater acceptability by cancer survivors compared to the standard 30-minute bout of walking or resistance training; and 3. The different PA strategies will have similar effects on glycemic outcomes for both breast cancer survivors and cancer-free controls. The resistance exercise session is an exploratory trial as the effects of it on acute glycemic control are understudied.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

NONE

Enrollment

Conditions

Breast Cancer

Interventions

Standard Physical Activity - FastedBEHAVIORAL

30 minutes of walking at a self-selected pace that they must have completed 15 minutes prior to consumption of first meal in the morning.

Standard Physical Activity - Post-MealBEHAVIORAL

30 minutes of walking at a self-selected pace to start 30 minutes after the start of the first meal in the morning.

Dispersed Physical ActivityBEHAVIORAL

10 minutes of walking at a self-selected pace to start 30 minutes after the start of each main meal throughout the day (i.e., three bouts total).

Physical Activity SnacksBEHAVIORAL

2 minutes of walking or marching on the spot at a self-selected pace every 30 minutes throughout the day for 7.5 waking hours.

Muscle StrengtheningBEHAVIORAL

30 minutes of muscle strengthening exercises targeting the major muscle groups of the whole body, to start 30 minutes after the start of the first meal in the morning.

Eligibility

Sex: FEMALEHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Postmenopausal biological females diagnosed with stage I, II, or III breast cancer and currently using aromatase inhibitors (AI) for at least 3 months prior to start of study participation * All participants must meet the following criteria: * Body mass index equal to or greater than 25 kg/m\^2. * Self-report consuming three main meals daily. * Self-report as being sedentary (i.e., less than 30 minutes/week of moderate-to-vigorous aerobic physical activity and less than twice/week muscle strengthening of major muscle groups in the last three months. Exclusion Criteria: * If unable or unwilling to receive medical clearance by a physician after being screened for major signs or symptoms of cardiovascular diseases, diabetes, or renal disease and safety to initiate exercise. * Major signs or symptoms of cardiovascular diseases, diabetes, or renal disease are taken from the American College of Sports Medicine's Guidelines for Exercise Testing and Prescription 11th edition Table 2.1. They include pain or discomfort in the chest, neck, jaw, arms with rest or exercise, shortness of breath at rest or with mild exertion, dizziness or syncope, ankle edema, palpitations or tachycardia, intermittent claudication, known heart murmur, and unusual fatigue with usual activities. * Safety to initiate exercise will be screened using the Get Active Questionnaire, which is the Canadian Society of Exercise Physiology's endorsed evidence-based pre-screening tool. * Using drugs for diabetes management (e.g., exogenous insulin, Ozempic, metformin, etc.) or actively losing weight (i.e., \>5 kg weight loss in past 3 months) from drugs or other reasons * Report any injury or other reason for not feeling capable of completing a 30 minute continuous walk or muscle strengthening exercise * Unable to access an Ontario Lifelabs location for an overnight fasted blood draw * Do not have a smartphone compatible with the applications required to collect data. * Cannot read and understand the consent form or communicate in English.

Outcomes

Primary Outcomes

24-hour glucose incremental area under the curve (iAUC)

Assessed for each single-day intervention using a continuous glucose monitor from 8:00 am to the intervention day to 8:00 am the following morning.