Reductions in ambulatory blood pressure in young normotensive men and women after isometric resistance training and its relationship with cardiovascular reactivity.

Background: There has been very little published work exploring the comparative effects of isometric resistance training (IRT) on blood pressure (BP) in men and women. Most of the previously published work has involved men and used resting BP as the primary outcome variable. Early evidence suggests that IRT is particularly effective in older women and has a positive influence on ambulatory BP, a better predictor of disease risk.

Objectives: With the WHO now placing global emphasis on the primary prevention of hypertension, the goals of this proof-of-concept study were to (i) examine whether sex differences exist in the ambulatory BP-lowering effects of IRT in young, normotensive men and women and (ii) determine whether these reductions can be predicted by simple laboratory stress tasks (a 2-min sustained isometric contraction and a math task involving subtracting a two-digit number from a series of numbers).

Results: There were no differences in the IRT-induced reductions in 24-h (men: Δ4 mmHg, women: Δ4 mmHg), daytime (men: Δ3 mmHg, women: Δ4 mmHg), or night-time (men: Δ4 mmHg, women: Δ3 mmHg) ambulatory BP in men (n=13) and women (n=11) (P<0.05) and these changes were not associated with systolic BP reactivity to either stress task (all P>0.05).

Conclusion: Our data suggest that lower ambulatory BP can be achieved, to a similar magnitude in young healthy women as well as men, with IRT; however, the BP-lowering effectiveness cannot be predicted by systolic BP reactivity. Taken together, this work heralds a potentially novel approach to the primary prevention of hypertension in both men and women and warrants further investigation in a larger clinical outcome trial.