Effectiveness of home-based high-intensity interval training on psychophysiological outcomes in adults: a systematic review

High-intensity interval training (HIIT) is a time-efficient exercise modality known for improving cardiorespiratory fitness and various health outcomes. Home-based HIIT offers an accessible and flexible option for individuals facing barriers to traditional exercise environments. This systematic review evaluates the effectiveness of home-based HIIT in enhancing physiological outcomes, assessing its capacity to deliver benefits comparable to those of supervised settings. Primary outcomes included cardiorespiratory fitness (V̇O₂ peak , exercise capacity). Secondary outcomes included metabolic parameters (insulin sensitivity, lipid profile), body composition (body mass, BMI, fat mass, waist circumference), and mental health. Eight studies were included, comprising three randomised controlled trials and five non-randomised studies. Participant mean age ranged from approximately 23 to 52 years, and mean BMI ranged from 21 to 35 kg/m². Across studies that reported sex distribution, participants included both males and females, although sex reporting was incomplete in several studies. Home-based HIIT elicited significant improvements in V̇O₂ peak across all studies, ranging from approximately 5% to 16%. Improvements in body composition were reported in four studies, including reductions in BMI and body fat percentage. Only one study assessed mental health related outcomes including SF-36 domains, psychological vitality, and affective state; however, depression, anxiety and stress outcomes remain underreported. Adherence was generally moderate-to-high across most studies, although reporting methods varied between interventions. Due to heterogeneity in participant populations, intervention protocols, supervision levels and outcome reporting, a narrative synthesis was undertaken. Current evidence suggests that home-based HIIT may improve cardiorespiratory fitness; however, further well-designed trials are required to examine long-term adherence, safety, and sustainability.