Author(s): BAROSS, T., BAXTER, B., WRIGHT, B., LANGDON, D., KAY, A. , Institution: UNIVERSITY OF NORTHAMPTON , Country: UNITED KINGDOM, Abstract-ID: 595

INTRODUCTION:
The World Health Organisation has reported hypertension, a major risk factor for stroke, coronary heart disease and cardiovascular-related mortality to be near epidemic levels globally with over 30% of the world’s population affected. Individually, isometric resistance training (IRT) has been established as one of the most efficacious nonpharmacological interventions for the prevention and treatment of hypertension, whilst eccentric exercise has also demonstrated improved cardiometabolic health in older populations (1). Simultaneous training (aerobic and isometric) produces larger reductions in resting blood pressure (BP) compared to single exercise protocols (2), however the effects of simultaneous isometric and eccentric training on cardiovascular parameters remain unknown. Therefore, the purpose of this study was to determine the effects of a 6-week simultaneous IRT and eccentric or concentric exercise intervention on resting cardiovascular parameters in young normotensives.
METHODS:
Fifty-four normotensive individuals (33 men, age = 21 ± 1 yr; 21 women, age = 20 ± 1 yr) were randomly assigned to four groups: simultaneous isometric exercise and stair descent (ISO-ECC, n = 14), simultaneous isometric exercise and stair ascent (ISO-CON, n = 13), isometric handgrip exercise (ISO, n = 13), or a passive control (CTRL, n = 14). Resting BP and haemodynamics (cardiac output, stroke volume, systemic vascular resistance) were measured prior to and after an incremental 6-week (3 day/week) training period. Initially participants completed 9 reps (1 repetition = 108 steps) of either stair ascending or descending in each session with the number of reps increasing by three each week. Sessional rate of perceived exertion was measured following each training session.
RESULTS:
The two-way ANOVA revealed a significant interaction effect (F3,48 = 3.198, P = 0.032, η_p^2 = 0.167) for resting systolic BP (SBP), with significant (P < 0.05) reductions in all training groups (ISO, 8 ± 9 mmHg; ISO-ECC, 8 ± 5 mmHg; ISO-CON, 6 ± 4 mmHg). SBP was significantly lower post-training in ISO compared to CTRL (10 ± 16 mmHg). No significant changes were revealed for all other measures (P > 0.05).
CONCLUSION:
All three training modalities were identified as efficacious therapeutic exercise interventions to lower SBP, however the magnitude of the change in SBP was greater in both the ISO and ISO-ECC groups, which were also perceived to be less demanding than the ISO-CON exercise. Although these results support the limited published data highlighting the hypotensive effects of eccentric exercise, as there was no difference in the reported decreases in SBP between the ISO and ISO-ECC groups, it may be more appropriate and time efficient to use the established isometric intervention if BP reduction is the main goal of the therapeutic exercise intervention.

1. Chen, TC. et al. (2017). Med. Sci. Sports Exerc. 49(8), 1614–1622.
2. Baross, AW. et al. (2017). J. Sport. Med. 2017, 1–6.