Chronotropic Responses to Exercise and Recovery in Myocardial Infarction Patients Taking ß-Blockers Following Aerobic High-Intensity Interval Training: AN INTERFARCT STUDY.

PURPOSE: The objectives of this study were to compare the effects of two different high-intensity interval training (HIIT) programs (low-volume vs high-volume) on chronotropic responses during exercise and recovery, and to contrast the results of the HIIT groups together to only physical activity recommendations in post-myocardial infarction (MI) patients taking ß-blockers. METHODS: Resting heart rate (HRrest), peak HR (HRpeak), HR reserve (HRreserve = HRpeak-HRrest), HR recovery (HRR) as the difference between HRpeak and post-exercise HR, and chronotropic incompetence were assessed in 70 patients (58 ± 8 yr) following MI with a cardiopulmonary exercise test to peak exertion before and after a 16-wk exercise intervention period. All participants were randomized to either attention control (AC) (physical activity recommendations) or one of the two supervised HIIT groups (2 d/wk). RESULTS: After the intervention, no significant between-HIIT group differences were observed. The HRpeak increased (P < .05) in low- (Δ= 8 ± 18%) and high-volume HIIT (Δ= 6 ± 9%), with a small decrease in AC (Δ=- 2 ± 12%, P > .05) resulting in large differences (P < .05) between HIIT and AC. The HRreserve increased (P < .05) in high-volume HIIT. The HRR slightly increased (P < .05) in low-volume (5th min, Δ= 19 ± 31%) and high-volume HIIT (2nd min, Δ= 15 ± 29%, and 5th min, Δ= 19 ± 28%). CONCLUSION: These findings suggest that both low- and high-volume HIIT elicit similar improvements in chronotropic responses after MI, independent of ß-blocker treatment. Supervised HIIT was more effective than giving physical activity recommendations alone. Low-volume HIIT is presented as a potent and time-efficient exercise strategy that could enhance the sympathovagal balance in this population.

Long-Term Effects in the EXERDIET-HTA Study: Supervised Exercise Training vs. Physical Activity Advice.

Purpose: To determine whether improvements in cardiorespiratory fitness (CRF), blood pressure (BP) and body composition previously seen after a 16-week exercise intervention (POST) with hypocaloric diet are maintained following six months (6M) of unsupervised exercise time. Methods: Overweight/obese, physically inactive participants with primary hypertension (HTN) (n = 190) were randomly assigned into an attention control group (physical activity recommendations) or one of three supervised exercise groups. After POST, all participants received diet and physical activity advice for the following 6M but no supervision. All anthropometric and physiological measurements were taken pre and post the 16-week supervised intervention period, as well as after 6M of no supervision. Results: After 6M: 1) body mass (BM) (Δ = 2.5%) and waist circumference (Δ = 1.8%) were higher (P < .005) than POST, but lower (P < .005) than pre-intervention (BM, Δ = -5.1%; waist circumference, Δ = -4.7%), with high-volume and high-intensity interval training group revealing a higher BM reduction (Δ = -6.4 kg) compared to control group (Δ = -3.5 kg); 2) BP variables were higher (P < .001) compared to POST with no change from pre-intervention; and 3) CRF was higher compared to pre-intervention (Δ = 17.1%, P < .001) but lower than POST (Δ = -5.7%, P < .001). Conclusions: When an overweight/obese population with HTN attains significant improvements in cardiometabolic health POST intervention with diet restriction, there is a significant reduction following 6M when exercise and diet supervision is removed, and only recommendations were applied. These results suggest the need for a regular, systematic and supervised diet and exercise programs to avoid subsequent declines in cardiometabolic health.

Low-Volume High-Intensity Aerobic Interval Training Is an Efficient Method to Improve Cardiorespiratory Fitness After Myocardial Infarction: PILOT STUDY FROM THE INTERFARCT PROJECT.

PURPOSE: To analyze the changes in cardiorespiratory fitness (CRF) and body composition following 2 different (low-volume vs high-volume) high-intensity aerobic interval training (HIIT) programs with Mediterranean diet (Mediet) recommendations in individuals after myocardial infarction (MI) and compared with an attention control group (AC). METHODS: Body composition and CRF were assessed before and after a 16-wk intervention in 70 participants (58.4 ± 8.5 yr) diagnosed with MI. All participants received Mediet recommendations and were randomly assigned to the AC group (physical activity recommendations, n = 14) or one of the 2 supervised aerobic exercise groups (2 d/wk training): high-volume (40 min) HIIT (n = 28) and low-volume (20 min) HIIT (n = 28). RESULTS: Following the intervention, no significant changes were seen in the AC group and no differences between HIIT groups were found in any of the studied variables. Only HIIT groups showed reductions in waist circumference (low-volume HIIT, Δ = -4%, P < .05; high-volume HIIT, Δ = -2%, P < .001) and improvements in CRF (low-volume HIIT, Δ = 15%, P < .01; high-volume HIIT, Δ = 22%; P < .001) with significant between-group differences (attention control vs HIIT groups). CONCLUSIONS: Results suggest that a 16-wk intervention (2 d/wk) of different HIIT volumes with Mediet recommendations could equally improve CRF and waist circumference after MI. Low-volume HIIT may be a potent and time-efficient exercise training strategy to improve functional capacity.

Actigraphy-based sleep analysis in sedentary and overweight/obese adults with primary hypertension: data from the EXERDIET-HTA study.

PURPOSE: The aim of this study was to analyze actigraphy-based sleep quantity and quality in sedentary and overweight/obese adults with primary hypertension (HTN) divided by sex and cardiorespiratory fitness (CRF) and to assess the association of sleep parameters with body composition, blood pressure (BP), and CRF. METHODS: This is a cross-sectional design utilizing data from the EXERDIET-HTA study conducted in 154 non-physically, obese adults with HTN (53.3 ± 7.8 years). Sleep parameters (total bedtime; total sleep time, TST; and sleep efficiency = (TST/total bedtime) × 100)) were calculated from raw accelerometer data (ActiGraph GT3X+). Peak oxygen uptake (V̇O2peak) determined the CRF. Blood pressure was assessed with the 24-h ambulatory BP monitoring. The distributions of V̇O2peak were divided into tertiles (low, medium, and high CRF) in each sex. Series of linear regression analyses were conducted between sleep, fitness, and health-related variables. RESULTS: Short sleep duration (6.2 h) both on weekdays and weekends, poor sleep quality (< 85% of efficiency), and no significant differences in sleep variables between women and men, nor among CRF groups, were observed. The short sleeping pattern was negatively associated (P < 0.05) with mean and night systolic BP (mmHg, ß = - 0.2), and sleep efficiency with waist circumference (cm, ß = - 0.08, P = 0.05). CONCLUSIONS: Actigraphy-based sleep analysis reinforces that sleep disorders, such as short sleep duration and poor sleep quality, are associated with high BP and abdominal obesity in sedentary adults with overweight/obesity and HTN. Sleep pattern did not appear to be related with CRF level in this population.

Effects of combined high-intensity aerobic interval training program and Mediterranean diet recommendations after myocardial infarction (INTERFARCT Project): study protocol for a randomized controlled trial.

BACKGROUND: Exercise therapy has long been used for rehabilitation purposes after myocardial infarction (MI) and the benefit of regular physical exercise is also well-established. High-intensity interval training (HIIT) has been proposed to be more effective than continuous exercise for improving exercise capacity and health-related adaptations to low-volume (LV) and HIIT are also known. Furthermore, the Mediterranean diet (Mediet) has been widely reported to be a model of healthy eating for its contribution to a favorable health status and a better quality of life, reducing overall mortality. This study will investigate the effects of different HIIT programs (high-volume [HV] vs LV) and Mediet recommendations in clinical condition, cardiorespiratory fitness, biomarkers, ventricular function, and perception of quality of life after MI, and compared to an attention control group that is recommended to Mediet and physical activity without supervision sessions. METHODS/DESIGN: In this randomized controlled trial, cardiorespiratory fitness, anthropometry, central and peripheral cardiovascular variables, biochemical and nutritional condition, and quality of life will be assessed before and after 16 weeks of intervention in 177 participants diagnosed with MI type 1. All participants will be randomly (1:1:1) assigned to the attention control group or two exercise groups (Mediet recommendations plus supervised aerobic exercise two days/week: (1) HV (40 min) HIIT group and (2) LV (20 min) HIIT group. DISCUSSION: This study will be the first clinical trial comparing the effects of two different volumes of HIIT programs with Mediet recommendations for people after MI. The results of this study will provide good evidence for physical rehabilitation in this population. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02876952 . Registered on 24 August 2016.

Effects of different aerobic exercise programmes with nutritional intervention in sedentary adults with overweight/obesity and hypertension: EXERDIET-HTA study.

Background Both exercise training and diet are recommended to prevent and control hypertension and overweight/obesity. Purpose The purpose of this study was to determine the effectiveness of different 16-week aerobic exercise programmes with hypocaloric diet on blood pressure, body composition, cardiorespiratory fitness and pharmacological treatment. Methods Overweight/obese, sedentary participants ( n = 175, aged 54.0 ± 8.2 years) with hypertension were randomly assigned into an attention control group (physical activity recommendations) or one of three supervised exercise groups (2 days/week: high-volume with 45 minutes of moderate-intensity continuous training (MICT), high-volume and high-intensity interval training (HIIT), alternating high and moderate intensities, and low-volume HIIT (20 minutes)). All variables were assessed pre- and post-intervention. All participants received the same hypocaloric diet. Results Following the intervention, there was a significant reduction in blood pressure and body mass in all groups with no between-group differences for blood pressure. However, body mass was significantly less reduced in the attention control group compared with all exercise groups (attention control -6.6%, high-volume MICT -8.3%, high-volume HIIT -9.7%, low-volume HIIT -6.9%). HIIT groups had significantly higher cardiorespiratory fitness than high-volume MICT, but there were no significant between-HIIT differences (attention control 16.4%, high-volume MICT 23.6%, high-volume HIIT 36.7%, low-volume HIIT 30.5%). Medication was removed in 7.6% and reduced in 37.7% of the participants. Conclusions The combination of hypocaloric diet with supervised aerobic exercise 2 days/week offers an optimal non-pharmacological tool in the management of blood pressure, cardiorespiratory fitness and body composition in overweight/obese and sedentary individuals with hypertension. High-volume HIIT seems to be better for reducing body mass compared with low-volume HIIT. The exercise-induced improvement in cardiorespiratory fitness is intensity dependent with low-volume HIIT as a time-efficient method in this population. ClinicalTrials.gov Registration: NCT02283047.

Association between Modified Shuttle Walk Test and cardiorespiratory fitness in overweight/obese adults with primary hypertension: EXERDIET-HTA study.

The aims of the study were to evaluate the relationship between Modified Shuttle Walk Test (MSWT) with peak oxygen uptake (V˙O2peak) in overweight/obese people with primary hypertension (HTN) and to develop an equation for the MSWT to predict V˙O2peak. Participants (N = 256, 53.9 ± 8.1 years old) with HTN and overweight/obesity performed a cardiorespiratory exercise test to peak exertion on an upright bicycle ergometer using an incremental ramp protocol and the 15-level MSWT. The formula of Singh et al was used as a template to predict V˙O2peak, and a new equation was generated from the measured V˙O2peak-MSWT relationship in this investigation. The correlation between measured and predicted V˙O2peak for Singh et al equation was moderate (r = 0.60, P < .001) with a standard error of the estimate (SEE) of 4.92 mL·kg-1 minute-1, SEE% = 21%. The correlation between MSWT and measured V˙O2peak as well as for the new equation was strong (r = 0.72, P < .001) with a SEE of 4.35 mL·kg-1 minute-1, SEE% = 19%. These results indicate that MSWT does not accurately predict functional capacity in overweight/obese people with HTN and questions the validity of using this test to evaluate exercise intolerance. A more accurate determination from a new equation in the current study incorporating more variables from MSWT to estimate V˙O2peak has been performed but still results in substantial error.