The impact of high-intensity interval training on ventricular remodeling in patients with a recent acute myocardial infarction-A randomized training intervention pilot study.

BACKGROUND: Aerobic exercise training is associated with beneficial ventricular remodeling and an improvement in cardiac biomarkers in chronic stable heart failure. High-intensity interval training (HIIT) is a time-efficient method to improve V ˙ O 2 peak in stable coronary heart disease patients. This pilot study aimed to compare the effect of HIIT on ventricular remodeling in patients with a recent acute myocardial infarction (AMI). METHODS: Nineteen post-AMI patients were randomized to either HIIT (n = 9) or usual care (n = 10). A cardiopulmonary exercise test (CPET), transthoracic echocardiography, and cardiac biomarker assessment (ie, N-terminal pro B-type natriuretic peptide levels and G protein-coupled receptor kinase 2 expression) were performed before and after a 12-week training intervention. CPET parameters including oxygen uptake efficiency slope (OUES) and V ˙ O 2 at the first ventilatory threshold ( V ˙ O 2 VT1) were calculated. left ventricular (LV) structural and functional echocardiographic parameters including myocardial strain imaging were assessed. RESULTS: V ˙ O 2 peak and OUES improved solely in the HIIT group (P < .05 for group/time, respectively). There was a significant training effect for the improvement of peak work load in both groups (P < .05). O2 pulse and V ˙ O 2 at VT1 both improved only in the HIIT group (P < .05 for time, no interaction). HIIT improved radial strain and pulsed-wave tissue Doppler imaging derived e' (P < .05 for time, no interaction). Cardiac biomarkers did not change in either group. CONCLUSIONS: In post-AMI patients, HIIT lead to significant improvements in prognostic CPET parameters compared to usual care. HIIT was associated with favorable ventricular remodeling regarding certain echocardiographic parameters of LV function.

Ambulatory blood pressure reduction following 2 weeks of high-intensity interval training on an immersed ergocycle.

BACKGROUND: Hypertension guidelines recommend moderate-intensity continuous training (MICT) for the primary or secondary prevention of hypertension. However, alternative modalities, such as high-intensity interval training (HIIT) on dry land or in water, have been studied less widely. AIM: To assess chronic blood pressure (BP) response to a 2-week training programme involving six sessions of either MICT or HIIT performed on dry land or HIIT performed in an immersed condition, in participants with baseline office systolic/diastolic BP (SBP/DBP)≥130/85mmHg. METHODS: We randomly assigned 42 individuals (mean age 65±7 years; 52% men) with baseline office SBP/DBP≥130/85mmHg to perform six 24-minute sessions on an ergocycle (three times a week for 2 weeks) of either MICT on dry land, HIIT on dry land or HIIT in a swimming pool, and assessed BP responses using 24-hour ambulatory BP monitoring. RESULTS: While 2-week MICT and HIIT on dry land modified none of the 24-hour average haemodynamic variables significantly, immersed HIIT induced a significant decrease in 24-hour BP (SBP -5.1±7.3 [P=0.02]; DBP -2.9±4.1mmHg [P=0.02]) and daytime BP (SBP -6.2±8.3 [P=0.015]; DBP -3.4±4.0mmHg [P=0.008]), and slightly improved 24-hour and daytime pulse wave velocity (PWV) (24-hour PWV -0.17±0.23m/s [P=0.015]; daytime PWV -0.18±0.24m/s [P=0.02]). CONCLUSION: HIIT on an immersed stationary ergocycle is an innovative method that should be considered as an efficient non-pharmacological treatment of hypertension. As such, it should now be implemented in a larger cohort to study its long-term effects on the cardiovascular system.

Ambulatory blood pressure reduction following high-intensity interval exercise performed in water or dryland condition.

We aimed to compare blood pressure (BP) responses following moderate-intensity continuous exercise (MICE), high-intensity interval exercise (HIIE) in dry land or HIIE in immersed condition, using 24-hour ambulatory BP monitoring. Forty-two individuals (65 ± 7 years, 52% men) with a baseline BP ≥ 130/85 mm Hg (systolic/diastolic blood pressures [SBP/DBP]) were randomly assigned to perform one of the three following exercises on a stationary cycle: MICE (24 minutes at 50% peak power output) or HIIE in dry land (two sets of 10 minutes with phases of 15 seconds 100% peak power output interspersed by 15 seconds of passive recovery) or HIIE in up-to-the-chest immersed condition. While MICE modified none of the 24-hour average hemodynamic variables, dryland HIIE induced a 24-hour BP decrease (SBP: -3.6 ± 5.7/DBP: -2.8 ± 3.0 mm Hg, P < .05) and, to a much greater extent, immersed HIIE (SBP: -6.8 ± 9.5/DBP: -3.0 ± 4.5 mm Hg, P < .05). The one condition that modified 24-hour pulse-wave velocity was immersed HIIE (-0.21 ± 0.30 m/s, P < .05).

Intensive lifestyle intervention including high-intensity interval training program improves insulin resistance and fasting plasma glucose in obese patients.

OBJECTIVES: To analyze the effects of a long-term intensive lifestyle intervention including high-intensity interval training (HIIT) and Mediterranean diet (MedD) counseling on glycemic control parameters, insulin resistance and ß-cell function in obese subjects. METHODS: The glycemic control parameters (fasting plasma glucose, glycated hemoglobin), insulin resistance, and ß-cell function of 72 obese subjects (54 women; mean age = 53 ± 9 years) were assessed at baseline and upon completion of a 9-month intensive lifestyle intervention program conducted at the cardiovascular prevention and rehabilitation center of the Montreal Heart Institute, from 2009 to 2012. The program included 2-3 weekly supervised exercise training sessions (HIIT and resistance exercise), combined to MedD counseling. RESULTS: Fasting plasma glucose (FPG) (mmol/L) (before: 5.5 ± 0.9; after: 5.2 ± 0.6; P < 0.0001), fasting insulin (pmol/L) (before: 98 ± 57; after: 82 ± 43; P = 0.003), and insulin resistance, as assessed by the HOMA-IR score (before: 3.6 ± 2.5; after: 2.8 ± 1.6; P = 0.0008) significantly improved, but not HbA1c (%) (before: 5.72 ± 0.55; after: 5.69 ± 0.39; P = 0.448), nor ß-cell function (HOMA-ß, %) (before: 149 ± 78; after: 144 ± 75; P = 0.58). CONCLUSION: Following a 9-month intensive lifestyle intervention combining HIIT and MedD counseling, obese subjects experienced significant improvements of FPG and insulin resistance. This is the first study to expose the effects of a long-term program combining HIIT and MedD on glycemic control parameters among obese subjects.

Provocative issues in heart disease prevention.

In this article, new areas of cardiovascular (CV) prevention and rehabilitation research are discussed: high-intensity interval training (HIIT) and new concepts in nutrition. HIIT consists of brief periods of high-intensity exercise interspersed by periods of low-intensity exercise or rest. The optimal mode according our work (15-second exercise intervals at peak power with passive recovery intervals of the same duration) is associated with longer total exercise time, similar time spent near peak oxygen uptake (VO2 peak) VO2 peak, and lesser perceived exertion relative to other protocols that use longer intervals and active recovery periods. Evidence also suggests that compared with moderate-intensity continuous exercise training, HIIT has superior effects on cardiorespiratory function and on the attenuation of multiple cardiac and peripheral abnormalities. With respect to nutrition, a growing body of evidence suggests that the gut microbiota is influenced by lifestyle choices and might play a pivotal role in modulating CV disease development. For example, recent evidence linking processed (but not unprocessed) meats to increased CV risk pointed to the gut microbial metabolite trimethylamine N-oxide as a potential culprit. In addition, altered gut microbiota could also mediate the proinflammatory and cardiometabolic abnormalities associated with excess added free sugar consumption, and in particular high-fructose corn syrup. Substantially more research is required, however, to fully understand how and which alterations in gut flora can prevent or lead to CV disease and other chronic illnesses. We conclude with thoughts about the appropriate role for HIIT in CV training and future research in the role of gut flora-directed interventions in CV prevention.