Oscillation intervals of cutaneous blood perfusion as indicators of aging

A total of 30 healthy participants (Old, aged >40 years, n=12; Young, age<40, n=18) were recruited, and their bilateral upper limb blood flow was recorded. The results showed that on either the left or right side, the average oscillation intervals of the lower age were significantly higher than those of the older age and that on the left or right side, the average interval was negatively and weakly correlated with age. The current study provides a window to access age-related changes on the oscillation interval of cutaneous laser Doppler flowmetry.

Effects of 4-Week Inspiratory Muscle Training on Sport Performance in College 800-Meter Track Runners

Background and objectives: Respiratory muscle fatigue is one of the important factors limiting sports performance due to the metaboreflex. This reflex will cause a decrease in blood flow to the extremities and accelerate exercising limb fatigue. Previous studies found that inspiratory muscle training (IMT) can effectively enhance the respiratory muscle endurance and reduce fatigue during long-duration exercise or aerobic exercise, thereby enhancing athletic performance. However, the mechanism between inspiratory muscle strength, change of limb blood flow and sports performance still requires investigation, especially in short-duration exercise, anaerobic or both aerobic and anaerobic exercise. The purpose of this study was to investigate the effects of 4-week inspiratory muscle training on respiratory muscle strength, limb blood flow change rate and sports performance in recreational 800-m college runners. Materials and Methods: Twenty healthy 800-m college runners randomized into the IMT group (11 subjects) and control group (9 subjects). IMT consisted of 30 inspiratory efforts twice daily, 5 days a week, with intensity at 50%, 60%, 70% and 80% of maximum inspiratory pressure (MIP) for 4 weeks, while a control group kept 50% of MIP for 4 weeks. An 800-m trial test, limb blood flow change rate by using Impedance Plethysmography, and MIP were as the outcome measured variables and be evaluated. All measured variables were assessed before and after 4-week IMT training. Two-way ANOVA was conducted for statistical analysis. Results: The results showed significantly interaction between groups and pre-posttest. IMT group significantly decreased limb blood flow change rate from 19.91 ± 11.65% to 9.63 ± 7.62% after received the IMT training program (p < 0.05). The MIP significantly improved from 112.95 ± 27.13 cmH2O to 131.09 ± 28.20 cm H2O in IMT group, and the 800-m trial test also shorted the running time from 162.97 ± 24.96 s to 156.75 ± 20.73 s. But the control group no significantly changed in MIP and 800-m trial test. Conclusions: Our results indicated that the 4-week IMT training (twice a day, 5 days a week) significantly improves participants’ inspiratory muscle strength, 800-m running performance and decreases the limb blood flow change rate.

The Effect of Lower Limb Revascularization on Flow, Perfusion, and Systemic Endothelial Function: A Systematic Review

Peripheral arterial disease (PAD) is associated with reduced lower limb blood flow and tissue perfusion. The consequent reduction in vessel wall shear stress as well as ischemia–reperfusion injury has also been associated with systemic endothelial dysfunction and inflammation. We aimed to explore the impact of lower limb revascularization on (1) lower limb blood flow, (2) tissue perfusion, and (3) systemic endothelial function. We performed a systematic literature search using the MEDLINE, Embase, and Web of Science databases. Eligible studies measured changes in lower limb blood flow, perfusion, or systemic endothelial function following revascularization for the treatment of symptomatic PAD. We found 19 eligible studies, which were limited by considerable heterogeneity. Current evidence suggests that revascularization has a positive effect on flow, perfusion, and systemic endothelial dysfunction. Any changes may take a number of weeks to become apparent. There is a need for well-designed studies to explore the association between flow, perfusion, and endothelial dysfunction.