The Effect of Exercise Intensity on Adherence

This study aims to advance the knowledge of a novel strategy of exercise to help people achieve the health benefits of exercise in less commitment time. As opposed to the traditionally recommended long periods (60 min) of moderate intensity exercise, this study will examine the effects of two exercise programs which consist of different intensities and repeated bouts of short intense exercise followed by rest periods. By incorporating short intense bouts of exercise, it may be possible that individuals enjoy this strategy of exercising more, which may influence them to continue to train in this way, increase their exercise levels in daily life and achieve exercise-related health benefits. Overall healthy women will be divided into a novel sprint interval training group or a high intensity interval training group or a traditional moderate intensity continuous training group. To evaluate the success of each training approach, a health-related quality of life questionnaire, one mile run test, weight, strength test and adherence to study requirements will be assessed over a 6-week period. The investigators hypothesize that the sprint interval training group will experience greatest strength measurements, will lose most body fat, have the greatest exercise benefits and will enjoy the novel training program more and will therefore adhere to the program more than the moderate continuous training group.

Since the majority of the population is inactive, this study is being done to develop a better strategy that might encourage people to exercise more and improve their health. The current physical activity guidelines suggest that adults aged 18-64 should perform at least 150 minutes of moderate- to vigorous-intensity aerobic physical activity per week . However, 84% of the Canadian population is insufficiently active. The large percentage of inactive individuals may be due to the daunting expectation that individuals must exercise for long periods of time to achieve health benefits, and many individuals report not having enough time. However, studies have shown that exercising for short, repeated bouts of intense exercise resulted in improved cardiometabolic health to the same extent as traditional endurance training, despite lower exercise volume. One study found that the prescription for a higher frequency of exercise significantly increased the accumulation of exercise without a negative effect on adherence. Further, in another study, participants who performed short intense bouts of physical activity have shown greater adherence than participants who were performing traditional exercise, working at a moderate intensity for a prolonged exercise period (89% and 71%, respectively). None of the studies mentioned above examined time matched exercise groups and included varying intensities of exercise, and collected data through virtual means, mimicking the natural environment of participants. The investigators believe that the proposed study will address these concerns and therefore advance the knowledge of sprint interval training.

Eligibility Criteria:
Inclusion Criteria:

* Female
* Participants must be between 20-49 years old
* Sedentary- completing less than 1 hour per week of leisure time physical activity over the prior 12 months and/or not meeting the CSEP guidelines of 150 minutes of moderate to vigorous physical activity per week
* Generally healthy males and females, no racial or gender bias.

Exclusion Criteria:

* Male
* Diagnosis of diabetes
* Taking glucose lowering medication
* Uncontrolled hypertension blood pressure \>160/90
* History of heart disease
* Previous myocardial infarction or stroke
* Contraindications of exercise