Unpacking the debate: A qualitative investigation of first-time experiences with interval exercise

Objective
There has been compelling debate about whether interval exercise should be promoted in public health strategies as a means of eliciting the health and fitness adaptations associated with physical activity behavior, particularly among individuals who are inactive. Despite a rapidly growing body of quantitative research, there is a notable absence of qualitative research on the topic. This study used a series of interviews conducted over time to develop a richer understanding of inactive adults’ experiences and perceptions of moderate-intensity continuous training (MICT), high-intensity interval training (HIIT), and sprint interval training (SIT) over time and factors that may influence their participation in these types of exercise.

Methods
Thirty inactive young adults (18 women, 12 men) completed three lab-based trials of cycling exercise in a random order on separate days: MICT, HIIT, and SIT, and subsequently logged their free-living exercise over four weeks. Interviews were conducted at five timepoints and subjected to a reflexive thematic analysis.

Results
Three overarching themes were constructed: (1) interval exercise sounds appealing, but is it for me? (2) exercise trade-offs – the value of interval vs. traditional exercise, and (3) real-world exercise adaptations to make it on your own.

Conclusions
The findings emphasize that people respond differently to different forms of exercise and the factors that influence participation in interval or continuous exercise are far more complex than can be captured by quantitative methodologies alone. Results suggest there is indeed a place for interval exercise in exercise plans and programs for the general population and interval exercise can be used concurrently with continuous exercise.