Prevalence and predictors of dropout from high‐intensity interval training in sedentary individuals: A meta‐analysis

Abstract

Recent evidence suggests that high-intensity interval training (HIIT) is an effective method to improve fitness and various health markers. However, the tolerability and acceptability of HIIT among sedentary individuals is currently controversially discussed. Therefore, our objective was to investigate the prevalence and predictors of dropout among sedentary individuals in HIIT-based exercise interventions. MEDLINE/PubMed, SPORTDiscus, and Web of Science were searched systematically for relevant articles until 06/2018. Studies included were required to (a) be written in English, (b) include sedentary healthy adults, (c) use some form of HIIT without any complementary intervention, (d) last ≥4 weeks, (e) report detailed description of the applied HIIT protocol, and (f) report data that allow calculation of a dropout rate. Fifty-five studies reporting results from 67 HIIT interventions with 1318 participants met the eligibility criteria. The trim and fill adjusted pooled dropout rate across all interventions was 17.6% (95% confidence interval 14.2-21.5%). Dropout rates were significantly lower in cycling-based interventions compared with studies using running/walking as exercise modality (P < 0.001). Longer session time (β = 0.02, P < 0.05), higher time effort/week (β = 0.005, P < 0.05), and overall time effort/intervention (β = 0.0003, P < 0.05) predicted greater dropout. Exercise intensity was not related to dropout. Our data suggest that HIIT-based interventions are tolerable and acceptable for previously sedentary individuals, exhibiting generally lower dropout rates than commonly reported for traditional exercise programs. Given the association between HIIT volume and dropouts, future studies should further focus on identifying the minimally effective dose of practical HIIT for improving health status. Such efforts would be important to increase implementation and public health impact of HIIT. K E Y W O R D S cardiorespiratory fitness, exercise adherence, feasibility, health promotion, public health, sprint interval training | 1289 RELJIC Et aL.

The Physiological, Physical, and Biomechanical Demands of Walking Football: Implications for Exercise Prescription and Future Research in Older Adults

“…In older adults, HIIT has been shown to improve metabolic (Søgaard et al, 2018) and cardiovascular health (Izadi, Ghardashi Afousi, Asvadi Fard, & Babaee Bigi, 2018), as well as muscle mitochondrial content (Wyckelsma et al, 2017). However, high dropout rates have been observed during HIIT programmes (Reljic et al, 2019). Therefore, the physiological and psychological benefits of walking football compared to traditional HIIT warrants further investigation, including adherence to the program of exercise, and affective responses during sessions.…”

A Qualitative Analysis of an Aerobic Interval Training Programme for Obese Outpatients Carried Out in a Hospital Context

“…The use of AIT for the exercise training protocol may have influenced the adherence to the programme. The positive benefits of enjoyment, short exercise protocol when compared to moderate continuous exercise protocols are particularly important for sedentary people and patients [32] Moreover, HIIT protocols have been encouraged for obtaining similar fat loss [33] or more absolute fat loss [34] when compared to moderate intensity continuous exercise protocols.…”

Feasibility of a progressive protocol of high-intensity interval training for overweight/obese, sedentary African American women: a retrospective analysis

“…The reason(s) for this lack of coherence regarding how well HIIT is physically and/or psychologically tolerated by individuals unaccustomed to exercise is unclear, but might represent different HIIT protocols that were investigated and/or different populations that were studied. With respect to the former, variables that might be particularly important to consider are the intensity at which HIIT work intervals are performed and the volume of the HIIT protocol [ 12 ].…”

“…Generally speaking, HIIT work intervals are performed at an intensity that elicits ≥80% and, in most cases, 85–95% of maximal heart rate [ 3 ]; hence, a progressive scheme that spans this range might, in theory, be an applicable one during the initial stage of HIIT. In support of this possibility, in a recent systematic review and meta-analysis, Reljic et al found that training volume predicted dropout rate for sedentary individuals performing HIIT whereas exercise intensity did not [ 12 ]. This would support the belief that individuals who are unaccustomed to exercise should be able to tolerate both psychologically (e.g., maintain adherence to) and physically (e.g., achieve the intensity requirements of) such a progressive HIIT protocol during the initial stage of training as long as volume is not excessive [ 12 ].…”