Sara Maldonado-Martín

Heart Rate Variability: Effect of Exercise Intensity on Postexercise Response

The purpose of the present study was to investigate the influence of two exercise intensities (moderate and severe) on heart rate variability (HRV) response in 16 runners 1 hr prior to (-1 hr) and at +1 hr, +24 hr, +48 hr, and +72 hr following each exercise session. Time domain indexes and a high frequency component showed a significant decrease (p < .001) between -1 hr and +1 hr for severe intensity. The low frequency component in normalized units significantly increased (p <.01) for severe intensity at +1 hr. Only severe exercise elicited a change in HRV outcomes postexercise, resulting in a reduction in the parasympathetic influence on the heart at +1 hr; however, values returned to baseline levels by +24 hr.

The effect of a multidisciplinary intervention program on hepatic adiposity in overweight-obese children: protocol of the EFIGRO study.

BACKGROUND Non-alcoholic fatty liver disease is the most frequent liver abnormality observed in overweight or obese children and is strongly associated with metabolic syndrome and insulin resistance. OBJECTIVES (i) To evaluate the effect of a 22-week multidisciplinary intervention program on hepatic fat fraction in overweight or obese children and (ii) to examine the effect of the intervention on cardiometabolic risk factors, self-esteem and well-being. METHODS A total of 160 children, 9-11 years, will be recruited by pediatricians and randomly assigned to control (N = 80) or intervention (N = 80) groups. The control group will receive a family-based lifestyle and psycho-educational program (2 days/month), while the intervention group will attend the same lifestyle education and psycho-educational program plus the exercise program (3 days/week). The duration of training sessions will be 90 min of exercise, including warm-up, moderate to vigorous aerobic activities, and strength exercises. The primary outcome is the change in hepatic fat fraction (magnetic resonance imaging, MRI). Secondary outcomes include cardiometabolic risk factors such as total adiposity (dual Xray absorptiometry), visceral adiposity (MRI), functional peak aerobic capacity (cardiopulmonary exercise testing), blood pressure, muscular fitness, speed–agility, and fasting blood insulin, glucose, C-reactive protein, alanine aminotransferase, aspartate aminotransferase, gamma glutamyltransferase, lipid profile and psychological measurements (questionnaires). All the measurements will be evaluated at baseline prior to randomization and after the intervention. DISCUSSION This study will provide insight in the efficacy of a multidisciplinary intervention program including healthy lifestyle education, psycho-education and supervised exercise to reduce hepatic fat and cardiometabolic risk in overweight children.

Effects of Different Aerobic Exercise Programs with NutritionalIntervention in Primary Hypertensive and Overweight/Obese Adults:EXERDIET-HTA Controlled Trial

Background: Both exercise training and diet are recommended to prevent and control primary hypertension (HTN) and overweight/obesity. Aerobic exercise is firmly established as an effective measure for lowering blood pressure (BP) and reducing cardiovascular risk. However, there is no agreement about the optimal dose of frequency, intensity, time and type of exercise. This study is a randomized control trial to investigate the effectiveness of different aerobic exercise programs and diet for reducing BP, for improving body composition, cardiorespiratory fitness, biochemical profile, physical activity and sedentary behavior and health-related quality of life in adults with primary HTN and overweight or obesity. Methods/Design: One hundred sixty-four overweight or obese participants (18-70 yr old) diagnosed with primary HTN will perform different assessments to evaluate BP, physical, biochemical and nutritional condition, sedentary behavior and quality of life before and after 16-week of follow-up. All participants will receive an energy-hypocaloric diet based on 25% of measured resting metabolic rate and will be randomly assigned to control group (only diet) or exercise groups (diet plus aerobic exercise). Participants assigned to an exercise group will train 2 days/week under supervision (treadmill and bike protocol). There will be three aerobic exercise groups: (1) moderate continuous exercise and high volume (MCT) group, (2) high-intensity interval training and high-volume (HV-HIIT) group, and (3) high-intensity interval training and low-volume (LV-HIIT) group. The measurements used in the protocol will be taken before and after the intervention period (16-weeks), and after a six-month period in all participants (i.e., 6 months with only recommendations and no supervision). Discussion: The results of this intervention will help to better understand the potential of non-pharmacological treatment for improving the well-being of people with primary HTN and overweight or obesity.

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 6-Minute Walk Test Distance and Objective Variables of Functional Capacity After Exercise Training in Elderly Heart Failure Patients With Preserved Ejection Fraction: A Randomized Exercise Trial

OBJECTIVE To evaluate the change in the 6-minute walk test (6-MWT) distance relative to changes in key functional capacity measures after 16 weeks of exercise training in older patients (≥65y) who have heart failure with preserved ejection fraction (HFpEF). DESIGN Prospective, randomized, single-blinded (by researchers to patient group) comparison of 2 groups of HFpEF patients. SETTING Hospital and clinic records; ambulatory outpatients. PARTICIPANTS Participants (N=47) randomly assigned to an attention control (AC) (n=24) or exercise training (ET) (n=23) group. INTERVENTION The ET group performed cycling and walking at 50% to 70% of peak oxygen uptake (V˙o2peak) intensity (3d/wk, 60min each session). MAIN OUTCOME MEASURES V˙o2peak, ventilatory threshold (VT), and 6-MWT distance were measured at baseline and after the 16-week study period. RESULTS At follow-up, the 6-MWT distance was higher than at the baseline in both the ET (11%, P=.005) and AC (9%, P=.004) groups. In contrast, V˙o2peak and VT values increased in the ET group (19% and 11%, respectively; P=.001), but decreased in the AC group at follow-up (2% and 0%, respectively). The change in V˙o2peak versus 6-MWT distance after training was also not significantly correlated in the AC group (r=.01, P=.95) or in the ET group (r=.13, P=.57). The change in 6-MWT distance and VT (an objective submaximal exercise measure) was also not significantly correlated in the AC group (r=.08, P=.74) or in the ET group (r=.16, P=.50). CONCLUSIONS The results of this study challenge the validity of using the 6-MWT as a serial measure of exercise tolerance in elderly HFpEF patients and suggest that submaximal and peak exercise should be determined objectively by VT and V˙o2peak in this patient population.

INFLUENCE OF PEDALING TECHNIQUE ON METABOLIC EFFICIENCY IN ELITE CYCLISTS

Our objective was to investigate the influence of pedaling technique on gross efficiency (GE) at various exercise intensities in twelve elite cyclists ( · VO2max=75.7 ± 6.2 mL·kg -1 ·min -1 ). Each cyclist completed a · VO2max assessment, skinfold measurements, and an incremental test to determine their lactate threshold (LT) and onset of blood lactate accumulation (OBLA) values. The GE was determined during a three-phase incremental exercise test (below LT, at LT, and at OBLA). We did not find a significant relationship between pedaling technique and GE just below the LT. However, at the LT, there was a significant correlation between GE and mean torque and evenness of torque distribution (r=0.65 and r=0.66, respectively; p < 0.05). At OBLA, as the cadence frequency increased, the GE declined (r=-0.81, p < 0.05). These results suggest that exercise intensity plays an important role in the relationship between pedaling technique and GE.

Influence of test duration on oxygen uptake attained during treadmill running

Abstract Previous investigations have revealed that in well-trained middle-distance runners, oxygen uptake (VO2) does not attain maximal values (VO2max) in exhaustive treadmill trials where the VO2 demand exceeds VO2max. To date, this shortfall in the VO2 attained has been demonstrated in trials as short as 2 min in duration. In this study, we investigated whether a reduction in exhaustive test duration influences the VO2 attained during running on a treadmill. Six middle-distance runners participated in the study, completing an exhaustive 400 m and 800 m trial. These trials, together with a progressive test to determine VO2max, were completed in a counterbalanced order. Oxygen uptakes attained during the 400 m and 800 m trials were compared to examine the influence of exhaustive test duration. A plateau in VO2 was observed in all participants for the progressive test, demonstrating the attainment of VO2max. The mean speed, duration, and resulting distance in the constant-speed exhaustive trials were 25.8 km · h−1 (s=1.2), 55.8 s (s=2.3), and 400.2 m (s=20.2) for the 400 m trial, and 24.3 km · h−1 (s=0.8), 108.4 s (s=21.2), and 730.1 m (s=129.1) for the 800 m trial, respectively. A paired-samples t-test revealed a significantly different (P=0.018)%VO2max was attained for the 400 m (85.7%, s=3.0) and 800 m (89.1%, s=5.0) trials. In conclusion, VO2 did not reach VO2max during the exhaustive constant-speed 400 m and 800 m trials, but the test duration does influence the%VO2max achieved. Specifically, the VO2 attained becomes progressively further below VO2max as trial duration is reduced, such that 89% and 86% VO2max is achieved in exhaustive 800 m and 400 m constant-speed trials, respectively.

Clinical, physical, physiological, and dietary patterns of obese and sedentary adults with primary hypertension characterized by sex and cardiorespiratory fitness: EXERDIET-HTA study

ABSTRACT The main purpose of this study was to determine some key physical, physiological, clinical, and nutritional markers of health status in obese and sedentary adults (54.0 ± 8.1 years, 141 men and 68 women) with primary hypertension (HTN) characterized by sex and cardiorespiratory fitness (CRF) level. The studied population showed a high cardiovascular risk (CVR) profile including metabolically abnormal obese, with poor CRF level (22.5 ± 5.6 mL·kg−1·min−1), exercise-induced HTN (Systolic Blood Pressure>210 mmHg in men and >190 mmHg in women at the end of the exercise test) and with non-healthy adherence to dietary pattern (Dietary Approaches to Stop Hypertension, 46.3%; Mediterranean Diet, 41.1%; and Healthy Diet Indicator, 37.1%). Women showed a better biochemical and dietary pattern profile than men (lower values, P < 0.05, in triglycerides, mean difference = 26.3; 95% CI = 0.9–51.7 mg/dL, aspartate transaminase, mean difference = 4.2; 95% CI = 0.3–8.0 U/L; alanine transaminase, mean difference = 8.2; 95% CI = 1.6–14.8 U/L; gamma-glutamyl transpeptidase, mean difference = 11.0; 95% CI = -1.1–23.2 U/L and higher values, P = 0.002, in high-density lipoprotein cholesterol, mean difference = 5.0, 95% CI = -13.3–3.3 mg/dL), but physical and peak exercise physiological characteristics were poorer. A higher CRF level might contribute to the attenuation of some CVR factors, such as high body mass index, non-dipping profile, and high hepatic fat. The results strongly suggest that targeting key behaviors such as improving nutritional quality and CRF via regular physical activity will contribute to improving the health with independent beneficial effects on CVR factors.

Effects of long-term training cessation in young top-level road cyclists

ABSTRACT In cycling, it is common practice to have a break in the off season longer than 4 weeks while adopting an almost sedentary lifestyle, and such a break is considered to be long-term detraining. No previous studies have assessed the effect of training cessation with highly trained young cyclists. The purpose of the present investigation was to examine effects of 5 weeks of training cessation in 10 young (20.1 ± 1.4 years) male road cyclists for body composition, haematological and physiological parameters. After training cessation, body mass of cyclists increased (P = 0.014; ES = 0.9). (L · min−1 = −8.8 ± 5.0%, mL · kg−1·min−1 = −10.8 ± 4.2%,), Wmax (W = −6.5 ± 3.1%, W · kg−1 = −8.5 ± 3.3%,), WLT1 (W = −12.9 ± 7.0%, W · kg−1 = −14.8 ± 7.4%,), WLT2 (W = −11.5 ± 7.0%, W · kg−1 = −13.4 ± 7.6%,) and haematological (red blood cells count, −6.6 ± 4.8%; haemoglobin, −5.4 ± 4.3% and haematocrit, −2.9 ± 3.0%) values decreased (P ≤ 0.028; ES ≥ 0.9). Five weeks of training cessation resulted in large decreases in physiological and haematological values in young top-level road cyclists suggesting the need for a shorter training stoppage. This long-term detraining is more pronounced when expressed relative to body mass emphasising the influence of such body mass on power output. A maintenance programme based on reduced training strategies should be implemented to avoid large declines in physiological values in young cyclists who aspire to become professionals.

Assessment of cardiovascular risk and vascular age in overweight/obese adults with primary hypertension: the Exerdiet-hta study.

Objective Hypertension (HTN), obesity and low cardiorespiratory fitness (CRF) are associated with an increased risk for a cardiovascular event. Enrolling overweight/obese individuals with HTN, the current study aimed to estimate cardiovascular risk (CVR) and vascular age (VA) profiles analyzing potential sex differences, determine whether VA is higher than chronological age, and whether CVR is associated with a low level of CRF. Methods Overweight/obese non-Hispanic White participants (n=209; 141 men and 68 women) with primary HTN had their CVR and VA determined using the New Pooled Cohort Risk Equations and The Framingham method, respectively. Considering values of peak oxygen uptake, participants were divided into tertiles for each sex. Results The CVR, but not VA (P=0.339), was higher (P<0.001) in men compared with women irrespective of age. Irrespective of sex, VA was higher than chronological age (P<0.001). Age and BMI were higher (P<0.05) in the low CRF group compared with that in other groups. There were no differences in CVR (P=0.907) and VA (P=1.643) when values were separated into CRF groups. Conclusion Pooled Cohort Equations could underestimate the risk of suffering a cardiovascular event in the following 10 years in overweight/obese non-Hispanic White women with HTN compared with men. The VA appears to be a useful tool in communicating CVR in this population irrespective of sex. The CRF alone may not be enough to moderate the CVR.