Set configuration influences cardiovascular responses to resistance exercise in postmenopausal females in a randomized crossover trial from the CARE project

Abstract

This study evaluated the acute cardiovascular responses to resistance exercise (RE) sessions with different set configurations in normotensive and hypertensive postmenopausal females. 50 physically active postmenopausal females performed a control (CON) and three RE sessions matched for total volume (144 repetitions), load (12-repetition maximum load), and total rest time (360s) but differing in set configuration: 4 sets of 9 repetitions with 120 s rest (9 S); 6 sets of 6 repetitions with 72 s rest (6 S); and 9 sets of 4 repetitions with 45 s rest (4 S). Heart rate (HR) was recorded during exercise, while HR variability, baroreflex sensitivity, arterial stiffness, and blood pressure were assessed before and after each session. Peak and mean HR values were higher during exercise in 9 S (p ≤ 0.026). All RE protocols induced cardiac parasympathetic withdrawal, reduction in baroreflex sensitivity, and increased post-exercise arterial stiffness compared to CON. However, in 4 S, cardiac parasympathetic withdrawal and baroreflex impairment were attenuated without a significant increase in arterial stiffness. Additionally, a post-exercise hypotensive response was observed only after 9 S in hypertensive participants (p = 0.004). Shorter set configurations attenuate chronotropic response during RE and mitigate impairments in cardiac autonomic and baroreflex control following RE sessions, without affecting arterial stiffness or blood pressure.

Keywords: Cardiovascular health; Climacteric; Cluster sets; Hemodynamics; Postmenopausal women; Strength training.

Fig. 1

(A) Schematic representation of the study. (B) Experimental and control protocols. (C) Experimental procedures. CPET = cardiopulmonary exercise test; FAM = familiarization session; 12RM test = 12-repetition maximum test. LP = leg press; BP = bench press; LC = leg curl; LPD = lat pulldown.

Fig. 2

Heart rate (HR) response before and after each condition (4 S: green circles; 6 S: orange triangles; 9 S: blue squares; CON: grey diamonds). # Significantly lower values in CON compared to all experimental conditions at the specific time point (p < 0.001 in all cases); * Significant difference between 4 S and 9 S at the specific time point (p < 0.05); ** Significant difference between 4 S and 9 S at the specific time point (p ≤ 0.001); @ Significant difference between 6 S and 9 S at the specific time point (p < 0.05).

Fig. 3

Cardiac autonomic control before and after each condition (4 S: green circles; 6 S: orange triangles; 9 S: blue squares; CON: grey diamonds). (A) LnSDNN: logarithm of the standard deviation of the R-R interval; (B) LnRMSSD: Logarithm of the root mean square of successive differences between adjacent R-R intervals; (C) LnHF: logarithm of the high-frequency power of the R-R interval in absolute values; (D) SampEn: sample entropy. # Significantly higher values in the control session at that time point compared to all experimental conditions (p < 0.001 in all cases); * Significant difference at the specific time point between 4 S and 6 S (p < 0.05); @ Significant difference at the specific time point between 4 S and 9 S (p < 0.05).

Fig. 4

Cardiovagal baroreflex and peripheral sympathetic tone responses before and after each condition (4 S: green circles; 6 S: orange triangles; 9 S: blue squares; CON: grey diamonds). (A) LnBRS_slope: logarithm of baroreflex sensitivity magnitude; (B) BRS_events: number of baroreceptor sequences detected; (C) BEI: baroreflex effectiveness index; (D) LnLF_sBP: logarithm of low-frequency power of systolic blood pressure; (E) SDsBP: standard deviation of systolic blood pressure; (F) SDMAP: standard deviation of mean arterial pressure. # Significantly higher values in the control session at that time point compared to all experimental conditions (p < 0.001 in all cases); $ Significantly higher values in the control session at that time point compared to 6 S and 9 S; * Significant difference at the specific time point between 4 S and 6 S (p < 0.05); @ Significant difference at the specific time point between 4 S and 9 S (p < 0.05); & Significantly higher values in the control session at that time point compared to 4 S and 6 S.

Fig. 5

Arterial stiffness response before, immediately after, and 60 min after each condition (4 S: green circles; 6 S: orange triangles; 9 S: blue squares; CON: grey diamonds). (A) Lnft-PWV: logarithm of finger-to-toe pulse wave velocity; (B) ABI: ankle-brachial index. # Significantly lower values in the control session at that time point compared to all experimental conditions (p < 0.001 in all cases); $ Significantly lower values in the control session at that time point compared to 9 S (p < 0.001).

Fig. 6

Blood pressure response before and after each condition (4 S: green circles; 6 S: orange triangles; 9 S: blue squares; CON: grey diamonds). (A) ΔsBP: relative changes in peripheral systolic blood pressure measured via photoplethysmography; (B) cSBP: central systolic blood pressure. In both cases, values represent estimated marginal means ± standard error of the mean and correspond to the interaction between hypertensive status and condition. # Significant differences compared to the control session in the hypertensive group; $ Differences with 6 S within the hypertensive group (trend: p = 0.051); * Differences between hypertensive and normotensive groups for a specific condition.