Time-efficient and computer-guided sprint interval exercise training for improving health in the workplace: a randomised mixed-methods feasibility study in office-based employees

Table 4 Themes arising from the qualitative interviews

Stage of protocol	Theme	Sub-theme
REHIT adopted / initiated	Time-appeal	Health and fitness benefits
		Limited time commitments required
		High self-efficacy due to brief exercise bouts
		Convenient location
Early stages of the exercise programme (≤15 s)	Positive perception of exercise bouts	Exercise bouts perceived as achievable
Early stages of the exercise programme (≤15 s)	Positive perception of exercise bouts	Positive psycho-social responses post-exercise
Later stages 20 s)	Highly negative perceptions of exercise bouts	Exercise bouts perceived as intensely demanding
	Highly negative perceptions of exercise bouts	Increasing reluctance to engage with exercise
		Positive feedback regarding progress towards health / fitness goals
	Adherence maintained	The use of cognitive and behavioural strategies
		Positive feedback
		Positive psycho-social responses post-exercise
		Habit
		Intention to commit long-term