Limb, sex, but not acute dietary capsaicin, modulate the near-infrared spectroscopy-vascular occlusion test estimate of muscle metabolism.

The downward slope during the near-infrared spectroscopy (NIRS)-vascular occlusion test (NIRS-VOT) is purported as a simplified estimate of metabolism. Whether or not the NIRS-VOT exhibits sex- or limb-specificity or may be acutely altered remains to be elucidated. Thus, we investigated if there is limb- or sex specificity in tissue desaturation rates (DeO2) during a NIRS-VOT, and if acute dietary capsaicin may alter this estimate of muscle metabolism. Young healthy men (n = 25, 21 ± 4 years) and women (n = 20, 20 ± 1 years) ingested either placebo or capsaicin, in a counterbalanced, single-blind, crossover design after which a simplified NIRS-VOT was conducted to determine the DeO2 (%/s), as an estimate of oxidative muscle metabolism, in both the forearm (flexors) and thigh (vastus lateralis). There was a significant limb effect with the quadriceps having a greater DeO2 than the forearm (-2.31 ± 1.34 vs. -1.78 ± 1.22%/s, p = 0.007, ηp 2 = 0.19). There was a significant effect of sex on DeO2 (p = 0.005, ηp 2 = 0.203) with men exhibiting a lesser DeO2 than women (-1.73 ± 1.03 vs. -2.36 ± 1.32%/s, respectively). This manifested in significant interactions of limb*capsaicin (p = 0.001, ηp 2 = 0.26) as well as limb*capsaicin*sex on DeO2 (p = 0.013, ηp 2 = 0.16) being observed. Capsaicin does not clearly alter O2-dependent muscle metabolism, but there was apparent limb and sex specificity, interacting with capsaicin in this NIRS-derived assessment.

Exploring the Bob Ross effect: A psychophysiological investigation.

Watching news broadcasts is known to elicit psychological stress. Conversely, the iconic painter Bob Ross (BR) has risen to pop culture status and amassed a following, as many find the messages and sounds of BR to be soothing and relaxing. Though, it has yet to be directly tested if such exposure can confer psychological or physiological benefit. The purpose of this study was to compare the effects of watching BR versus streaming news on markers of cardiovascular health and profile of mood states (POMS). It was hypothesized that watching BR would increase POMS scores and heart rate variability (HRV). It was also hypothesized that watching the news would increase blood pressure (BP), vascular stiffness (VS), and heart rate (HR). METHODS: In a randomized, controlled, crossover design, 18 young (21 ± 1 yrs, 9 female, 9 male) healthy participants (172.6 ± 9.9 cm, 69 ± 18 kg) were assessed for BP, VS, HR, HRV, and POMS before and after watching an episode of BR or the News matched for time (∼27 mins). RESULTS: A significant interaction effect on POMS scores were observed for, anxiety (p = 0.01), anger (p = 0.008), depression (p = 0.003), fatigue (p = 0.001), and confusion (p = 0.01) domains after watching BR. The LF/HF ratio, an HRV marker of sympathovagal balance, was significantly lower after watching BR (p = 0.04). There were no significant time, condition, or interaction effects on systolic BP, mean arterial pressure, and diastolic BP. CONCLUSION: The "Bob Ross Effect" reduces overall mood disturbance, though appears to exert little influence on the cardiovascular system in this acute paradigm.

The Impact of COVID-19 Health and Safety Measures on the Self-Reported Exercise Behaviors and Mental Health of College Students.

The public-health restrictions (e.g., remote learning, restricted access to facilities and dining halls) put in place by colleges to reduce the spread of COVID-19 resulted in forced isolation and modifications to health-related behaviors. The restrictions and uncertainty associated with COVID-19 may have exacerbated the challenges of meeting exercise recommendations and mental-health concerns. The purpose of this study was to assess the impact of restrictions on students' exercise habits and their levels of anxiety, stress, and depression. Five-hundred and forty students completed a 29-question survey on individual demographics, living arrangements, exercise, sleep, diet, and mental health. Significant changes in weekly days of exercise and intensity were reported. Increases in anxiety, stress, and depression were reported. The two most frequently reported changes in exercise behavior were an increase in minutes of aerobic training (5%) and a combination of reduced minutes of aerobic and resistance training (3.9%), which could be reflective of an individual's ability and/or desire to maintain exercise behavior during the restrictions. Alternatively, for those students who reduced their exercise habits, aerobic training (11%) was the mode that suffered the most. Demographic factors such as ethnicity, regional residence, and gender were found to have significant effects on stress, anxiety, and depression. Amidst pandemics and future health emergencies, colleges should prioritize establishing opportunities for students to exercise, helping them meet physical activity recommendations and combat mental-health issues.

Sex differences in estimates of cardiac autonomic function using heart rate variability: effects of dietary capsaicin.

PURPOSE: Heart rate variability (HRV) estimates the autonomic nervous system (ANS) influence on the heart and appears sex-specific. Sensory afferents exhibit sex-specificity; although, it is unknown if Capsaicin, an agonist for transient receptor potential vanilloid channel-1 (TRPV1), alters cardiac ANS activity in a sex-dependent manner, which could be important given the predictive nature of HRV on risk of developing hypertension. Thus, we explored if there was sex-specificity in the effect of capsaicin on estimated cardiac ANS activity. METHODS: HRV was measured in 38 young males (M: n = 25) and females (F: n = 13), in a blinded-crossover design, after acute ingestion of placebo or capsaicin. Resting HR, RR-interval, root-mean-square of successive differences (RMSSD), natural log-transformed RMSSD (LnRMSSD), standard deviation of n-n intervals (SDNN), number of pairs of successive n-n intervals differing by > 50 ms (NN50), and percent NN50 (PNN50) were obtained using standard techniques. RESULTS: Significant sex differences were observed in mean HR (M: 59 ± 9.3 vs. F: 65 ± 12 beats/min, p = 0.036, η2 = 0.098), minimum HR (M: 47 ± 8.3 vs. F: 56 ± 12 beats/min, p = 0.014, η2 = 0.124), and NN50 (M: 177 ± 143 vs. F: 29 ± 17, p < 0.001, η2 = 0.249). There was a significant interaction of sex*treatment (p = 0.02, η2 = 0.027) for RMSSD, where males increased (78 ± 55 vs. 91 ± 64 ms), and females decreased (105 ± 83 vs. 76 ± 43 ms), placebo vs. capsaicin. CONCLUSION: This controlled study recapitulates sex differences in HR and HRV, but revealed a sexual dimorphism in the parasympathetic response to capsaicin, perhaps due to differing TRPV1-afferent sensitivity, highlighting a potential mechanism for differential regulation of hemodynamics, and CVD risk, and should be considered in future studies.

Does sex influence near-infrared spectroscopy-derived indicators of microvascular reactivity and the response to acute dietary capsaicin.

Endothelial dysfunction is associated with cardiovascular disease development, nitric oxide (NO) deficiencies, and may be limb or sex-specific. Prior in vitro work indicated that the transient receptor potential vanilloid channel-1 (TRPV1) is expressed in human arteries and the TRPV1 agonist capsaicin alters vasodilation in an endothelium-dependent manner; however, it is unknown if this translates in vivo or is limb or sex-dependent. Therefore, we sought to determine if there was limb or sex-specificity in the effect of capsaicin on microvascular function using near-infrared spectroscopy (NIRS)-derived tissue oxygen saturation (StO2) reperfusion slope. In a blinded placebo-controlled crossover design, 45 young males (M: n = 25) and females (F: n = 20), the reperfusion slopes of the forearm and quadriceps were assessed, and a urine sample obtained to assay for nitrate/nitrite (NOx) concentrations and antioxidant capacity after acutely ingesting placebo or capsaicin. Under placebo, females had greater reperfusion rates in both the forearm (M: 0.44 ± 0.24 vs. F: 0.98 ± 0.46 %/sec; p = 0.002, d = -1.50) and quadricep (M: 0.86 ± 0.31 vs. F: 1.17 ± 0.43 %/sec; p = 0.010, d = -0.85). Capsaicin decreased microvascular responsiveness in the forearm of females (placebo: 0.98 ± 0.45 vs. capsaicin: 0.84 ± 0.45 %/sec) as compared to males (placebo: 0.45 ± 0.24 vs. capsaicin: 0.38 ± 0.16 %/sec, interaction p < 0.001, η2 = 0.475). There was a sex*treatment interaction for NOx concentrations, where males increased (placebo: 21.13 ± 12.83 vs. capsaicin: 23.82 ± 13.34 µM), while females decreased (placebo: 22.78 ± 14.40 vs. capsaicin: 14.43 ± 10.01 µM; p = 0.037, η2 = 0.042). Using NIRS to assess microvascular function, there is apparent limb and sex-specificity, and, for the first-time, document that acute oral capsaicin alters reperfusion slope in a sexually divergent manner.