Cardiovascular Adaptations to Resistance Exercise: Effect of Set Configuration on Postmenopausal Women

The main purpose of this project is to analyze the effect of set configuration of resistance exercise on cardiovascular responses and adaptations of postmenopausal women. Additionally, since previous studies have shown that individual´s blood pressure level can influence on the impact of resistance training programs on cardiovascular changes, we aim to contrast acute and chronic changes to resistance training programs in normotensive and hypertensive postmenopausal women.

Menopause causes hormonal changes that affect to acute and chronic physiological responses to exercise of postmenopausal women. In this regard, studies about the cardiovascular responses to resistance training in women are scarce, being particularly relevant to identify those load parameters that modulate these adaptations. Previous studies have identified that set configuration of muscular exercise influence on cardiovascular stress, albeit these results have been mainly obtained in healthy young male subjects.

The project is divided into two studies. The first one is devoted to contrast the acute effect of three resistance training sessions with the same volume, intensity, length a work-to-rest ratio, but differing in set configuration. Thus, a sample of 60 postmenopausal women (30 normotensive and 30 hypotensive) will be recruited in local sport facilities in order to carry out in a randomized order three experimental sessions and a control session. Before and after each session hemodynamic (systolic, diastolic and mean blood pressure), cardiac performance (heart rate, cardiac output, stroke volume among others), cardiac and vascular autonomic modulation (hear rate and blood pressure variability), baroreflex effectiveness (baroreflex sensitivity), neuromuscular fatigue, arterial stiffness and metabolic (lactate concentrations) responses and resting energy expenditure (oxygen consumption) will be evaluated. This first analysis will allow us to identify the two set configurations with the highest and the lowest cardiovascular stress respectively, being these exercise structures used in the second study, in which the effect of 12 weeks resistance training programs differing in set configuration will be contrasted. To do this, a sample of 40 postmenopausal women will be randomly assigned to a control group and to two resistance training programs (higher and lower set configuration respectively) which be carried out throughout 12 weeks with a frequency of 2 session per week. Training loads will be readjusted every four weeks. Before and after the training programs and after a 4 weeks follow-up period the following components will be evaluated: body composition by bioimpedance, muscular thickness by echography, neuromuscular performance (isokinetic torque-velocity and power-velocity relationship), resting metabolic rate by indirect calorimetry, foot bone mineral density, beat-to-beat blood pressure by photoplethysmography, cardiac performance by impedance cardiography , cardiac autonomic modulation by heart rate variability analysis, baroreflex sensitivity analysis, sympathetic vasomotor tone (blood pressure variability) and arterial stiffness. This project will provide useful information for optimizing the resistance exercise prescription for postmenopausal women by identifying exercise structures that potentially allow to preserve physiological adaptations and at the same time to blunt the acute cardiovascular stress.

Eligibility Criteria:
Inclusion Criteria:

* Five years since menopause
* Physically active (150-300 minutes a week of moderate physical activity or at least 75 minutes a week of vigorous physical activity)
* No more than 3 cardiovascular risk factors
* Asymptomatic and without cardiovascular (except hypertension), metabolic or renal disease
* Hypertensive women should be diagnosed with grade 1 hypertension that must be well controlled by one drug and with low or moderate cardiovascular risk.

Exclusion Criteria:

* Having grade 2 or 3 hypertension
* Participants with hypertension and taking more than one drug for controlling hypertension or by a drug that can interfere cardiovascular responses to exercise
* To be or have been receiving hormonal replacement therapy
* To show hypertensive response to exercise