• Exercise training
• Health promotion

High intensity interval training (HIIT) can produce similar if not greater improvements in cardiorespiratory fitness, an independent protective factor against premature death, and some health-related parameters compared to conventional, moderate intensity continuous training (MICT). HIIT takes substantially less time to complete and this enhances its potential in public health promotion given that lack of time is one of the barriers to long-term adherence to physical activity and exercise training. HIIT describes exercise bouts of 10 s to 4 min with ‘all-out’ maximal effort or intensities of 85–95% of maximum heart rate (HR_max) interspersed by periods of low activity or rest (30 s to 4 min). MICT describes prolonged continuous exercise at 60–80% HR_max.

Despite the accumulated evidence, very little improvement has been made in terms of HIIT implementation in real life settings given that most studies lack the required level of ecological validity (most are of healthy volunteers training under research-based conditions—this is far from …