Sex Differences in Measures of Wave Reflection and Aortic Arterial Stiffness in Response to Weight Machine Resistance Exercise

International Journal of Exercise Science 15(2): 1190-1201, 2022. While it has been demonstrated that acute resistance exercise (RE) alters measures of wave reflection and aortic arterial stiffness in young, healthy individuals, limited research has evaluated sex differences. Accordingly, we recruited moderately active, resistance-trained men (Age: 22 ± 3yrs, n=12) and women (23 ± 3yrs, n=10) to perform two randomized conditions consisting of an acute bout of weight machine RE or a quiet control (CON). Measures of aortic wave reflection and aortic stiffness were taken at baseline and 15 minutes following the RE (Recovery). At baseline, women had significantly higher heart rate (p = 0.05) and lower brachial systolic blood pressure (p = 0.009) compared to men. There were no significant three-way interactions for any variable. Significant condition by time interactions were noted for heart rate (Baseline: 65 ± 10bpm, Recovery: 87 ± 13bpm, p = 0.001), brachial systolic blood pressure (Baseline: 116 ± 9mmHg, Recovery: 123 ± 10mmHg, p = 0.014), and the augmentation index (AIx) normalized at 75bpm (Baseline: 7.7 ± 12.8%, Recovery: 15.5 ± 9.5%, p = 0.002) such that Recovery was augmented compared to Baseline following RE but not CON. There was also a significant main effect of time for augmentation pressure (Baseline: 4.1 ± 4.0mmHg, Recovery: 4.0 ± 3.6mmHg, p = 0.04) such that it decreased from Baseline to Recovery following RE but not the CON. There were no significant effects of sex, condition, or time on aortic arterial stiffness. Men and women have similar responses in measures of aortic wave reflection and aortic arterial stiffness following acute RE using weight machines

Vascular Responses to High-Intensity Battling Rope Exercise between the Sexes

The purpose of the study was to assess high-intensity battling rope exercise (HI-BRE) on hemodynamics, pulse wave reflection and arterial stiffness during recovery and between sexes. Twenty-three young, healthy resistance-trained individuals (men: n = 13; women: n = 10) were assessed for all measures at Rest, as well as 10-, 30-, and 60-minutes following HI-BRE. A one-way repeated measures ANOVA was used to analyze the effects of HI-BRE across time (Rest, 10, 30, and 60-minutes) on all dependent variables. Significant main effects were analyzed using paired t-tests with a Sidak correction factor. Significance was accepted a priori at p 0.05. There were significant reductions in hemodynamic measures of diastolic blood pressure (BP) in women, but not men following HI-BRE at 30 minutes. Further, measures of pulse wave reflection, specifically those of the augmentation index (AIx) and wasted left ventricular energy (ΔEw), were significantly increased in both men and women for 60 minutes, but changes were significantly attenuated in women suggesting less ventricular work. There were also significant increases in arterial stiffness in regard to the aorta and common carotid artery that were fully recovered by 30 and 60 minutes, respectively with no differences between men and women. Thus, the primary findings of this study suggest that measures of hemodynamics and pulse wave reflection are collectively altered for at least 60 minutes following HI-BRE, with women having attenuated responses compared to men

Cardiac Autonomic Function Following Bilateral and Unilateral Upper Body Acute Resistance Exercise

The purpose of this study was to compare cardiac autonomic responses following bilateral and unilateral upper-body (UB) acute resistance exercise (ARE). In total, 14 individuals were assessed for markers of cardiac autonomic responses via heart rate variability (HRV) and baroreflex sensitivity (BRS) at rest and at 10- and 30-min following ARE. Logarithmically transformed (ln) HRV measures included: total power (ln TP), high-frequency power (ln HF power), low-frequency power (ln LF power), sympathovagal balance (ln LF: HF), and the square root of the mean squared differences of successive R-R intervals (ln RMSSD). BRS was assessed using the sequence method. Two-way repeated measures ANOVAs were used to analyze effects of UB ARE (bilateral, unilateral) across time (Rest, 10, and 30 min). There were no significant (p &gt; 0.05) interactions. However, there were significant (p &lt;= 0.05) main effects of time such that ln TP, ln HF power, ln RMSSD, and BRS decreased and did not recover within 30 min compared to Rest for both conditions. Collectively, this study suggests that bilateral and unilateral UB ARE yielded similar reductions, for at least 30 min, in respect to vagal measures of HRV and BRS.</p

Effects of a Cool-Down after Supramaximal Interval Exercise on Autonomic Modulation

Supramaximal interval exercise alters measures of autonomic modulation, while a cool-down may speed the recovery of vagal modulation. The purpose of this study was to compare the effects of a cool-down (pedaling a cycle ergometer at 50 rpm against a resistance of 45 W) versus passive recovery (no pedaling) after supramaximal interval exercise on autonomic modulation. Sixteen moderately active individuals (Mean ± SD: 23 ± 3 years (men: n = 10; women: n = 6) were assessed for autonomic modulation at Rest, and 15 (R15), 30 (R30), 45 (R45) and 60 (R60) min following supramaximal interval exercise. Linear measures of autonomic modulation included natural log (ln) total power (lnTP), high-frequency power (lnHF), the ratio of low frequency (LF) to HF ln(LF/HF) ratio, root mean square of successive differences between normal heartbeats (lnRMSSD), while non-linear measures included sample entropy (SampEn) and Lempel–Ziv entropy (LZEn). Two-way repeated ANOVAs were used to evaluate the main effects of condition (cool-down, passive recovery) across time (Rest, and R15, R30, R45 and R60). There were significant (p ≤ 0.05) condition by time interactions for SampEn and LZEn, such that they decreased at 15, 30, 45 and 60 min during passive recovery compared to Rest, with the recovery of SampEn and LZEn by 60 and 45 min, respectively, during cool-down. There were significant (p ≤ 0.05) main effects of time for lnTP, lnHF and lnRMSSD, such that lnTP, lnHF and lnRMSSD were attenuated, and lnLF/HF ratio was augmented, at all recovery times compared to Rest. These data demonstrate that a cool-down increases the recovery of nonlinear measures of vagal modulation within 45–60 min after supramaximal interval exercise, compared to passive recovery in moderately active individuals.</p

Cannabis use for exercise recovery in trained individuals: a survey study

Abstract Background Cannabis use, be it either cannabidiol (CBD) use and/or delta-9-tetrahydrocannabinol (THC) use, shows promise to enhance exercise recovery. The present study aimed to determine if individuals are using CBD and/or THC as a means of recovery from aerobic and/or resistance exercise, as well as additional modalities that might be used to aid in recovery. Methods Following consent, 111 participants (Mean ± SD: Age: 31 ± 13 years) completed an anonymous survey. All participants were regularly using cannabis (CBD and/or THC) as well as were currently exercising. Questions pertained to level of cannabis use, methods used for consumption of cannabis, exercise habits, exercise recovery strategies, and demographics. Results Eighty-five percent of participants reported participating in aerobic training. In addition, 85% of participants also reported regular participation in resistance exercise. Seventy-two percent of participants participated in both aerobic and resistance exercise. Ninety-three percent of participants felt that CBD use assisted them with recovery from exercise, while 87% of participants felt the same regarding THC use. Conclusions Individuals who habitually use cannabis, CBD or THC, and regularly engage in exercise do feel that cannabis assists them with exercise recovery. More data are necessary to understand the role of cannabis in exercise recovery as well as perceived ergogenic benefits of cannabis by individuals who both regularly participate in exercise and habitually use cannabis