The Potential for High-Intensity Interval Training to Reduce Cardiometabolic Disease Risk

Abstract

In the US, 34% of adults currently meet the criteria for the metabolic syndrome defined by elevated waist circumference, plasma triglycerides (TG), fasting glucose and/or blood pressure, and decreased high-density lipoprotein cholesterol (HDL-C). While these cardiometabolic risk factors can be treated with medication, lifestyle modification is strongly recommended as a first-line approach. The purpose of this review is to focus on the effect of physical activity interventions and, specifically, on the potential benefits of incorporating higher intensity exercise. Several recent studies have suggested that compared with continuous moderate exercise (CME), high-intensity interval training (HIT) may result in a superior or equal improvement in fitness and cardiovascular health. HIT is comprised of brief periods of high-intensity exercise interposed with recovery periods at a lower intensity. The premise of using HIT in both healthy and clinical populations is that the vigorous activity segments promote greater adaptations via increased cellular stress, yet their short length, and the ensuing recovery intervals, allow even untrained individuals to work harder than would otherwise be possible at steady-state intensity. In this review, we examine the impact of HIT on cardiometabolic risk factors, anthropometric measures of obesity and cardiovascular fitness in both healthy and clinical populations with cardiovascular and metabolic disease. The effects of HIT versus CME on health outcomes were compared in 14 of the 24 studies featuring HIT. Exercise programmes ranged from 2 weeks to 6 months. All 17 studies that measured aerobic fitness and all seven studies that measured insulin sensitivity showed significant improvement in response to HIT, although these changes did not always exceed responses to CME comparison groups. A minimum duration of 12 weeks was necessary to demonstrate improvement in fasting glucose in four of seven studies (57%). A minimum duration of 8 weeks of HIT was necessary to demonstrate improvement in HDL-C in three of ten studies (30%). No studies reported that HIT resulted in improvement of total cholesterol, low-density lipoprotein cholesterol (LDL-C), or TG. At least 12 weeks of HIT was required for reduction in blood pressure to emerge in five studies of participants not already being treated for hypertension. A minimum duration of 12 weeks was necessary to see consistent improvement in the six studies that examined anthropometric measures of obesity in overweight/obese individuals. In the 13 studies with a matched-exercise-volume CME group, improvement in aerobic fitness in response to HIT was equal to (5 studies), or greater than (8 studies) in response to CME. Additionally, HIT has been shown to be safe and effective in patients with a range of cardiac and metabolic dysfunction. In conclusion, HIT appears to promote superior improvements in aerobic fitness and similar improvements in some cardiometabolic risk factors in comparison to CME, when performed by healthy subjects or clinical patient...

Effectiveness of High-Intensity Interval Training (HIT) and Continuous Endurance Training for VO2max Improvements: A Systematic Review and Meta-Analysis of Controlled Trials

“…It is therefore not surprising that recent meta-analyses [14][15][16][17] have confirmed HIT to be an appropriate training stimulus to improve cardiorespiratory fitness and reduce metabolic risk factors in patient populations. Using similar inclusion criteria to the afore-mentioned reviews, Bacon et al [18] meta-analysed the effect of HIT on VO2max but only calculated an overall effect size, irrespective of the type of control group (no exercise or endurance training).…”

“…In doing so, these reviews excluded HIT research utilizing longer interval durations and shorter recovery periods. While there have been meta-analyses on longer duration HIT repetitions in patient populations [14][15][16][17], to the best of the authors' knowledge there is no systematic review and meta-analysis examining the effect of longer duration HIT repetitions in comparison to either endurance training or no exercise controls. Therefore, our aim was to meta-analyse the effects on VO2max of endurance training and HIT in healthy, young to middle-aged adults, when compared to no exercise controls and also when the two types of training were compared to one another.…”

Efeito do treinamento intervalado de alta intensidade versus treinamento contínuo na composição corporal: uma revisão sistemática com meta-análise

“…Foi demonstrado que o HIIT pode ser mais efetivo em promover o aumento do VO2max 16 , além de se mostrar mais eficaz em relação ao tempo necessário para promover adaptações cardiometabólicas similares ao treinamento contínuo de intensidade moderada 17,18 . No mesmo sentido, Gibala & McGee 12 já destacavam o HIIT como uma ferramenta tempo-eficiente para promover adaptações semelhantes ao treinamento contínuo de intensidade moderada.…”

Respuestas metabólicas inducidas por ejercicio físico de alta intensidad en mujeres sedentarias con glicemia basal alterada e hipercolesterolemia

“…7 Facultad de educación, ciencias sociales y Humanidades, departamento de educación Física, universidad de la Frontera, temuco, chile. 8 2 . Adicionalmente, altos niveles de obesidad (64%) y sedentarismo (93%) han sido identificados como algunos de los principales factores de riesgo de estas condiciones en población chilena 1,3 .…”

“…A pesar de que recomendaciones de EF basadas en actividades aeróbicas de baja intensidad 5 y sobrecarga 6 han reportado importantes beneficios en el manejo de alteraciones metabólicas, una de las principales razones entregadas por la población para no cumplir con las recomendaciones de actividad física para la salud pública (150-300 min/ semana) es la "falta de tiempo" 7 . Poco se conoce respecto a los efectos de otros tipos de EF como el ejercicio intervalado de alta intensidad (HIT del inglés high intensity interval training), propuesto como una metodología tiempo-eficiente para el tratamiento de alteraciones metabólicas 8,9 .…”