Impact of training volume and intensity on RBC-NOS/NO pathway and endurance capacity

HIIT serves as an efficient training strategy for basketball players by improving blood fluidity and decreasing oxidative stress

BACKGROUND

A challenge for coaches and athletes is to find the best combination of exercises during training. Considering its favorable effects, HIIT has been very popular recently.

OBJECTIVE

The goal of this study was to investigate anthropometric features, performance, erythrocyte deformability, plasma viscosity (PV) and oxidative stress in response to acute and long-term (6 weeks) HIIT in adolescent basketball players.

METHODS

22 sportsmen between the ages of 14-16 were included. Tabata protocol was applied to the HIIT group in addition to their routine training program 3 days/week, for 6 weeks. Erythrocyte deformability was determined using an ectacytometer (LORCA), PV with a rotational viscometer. Total oxidant status (TOS), total antioxidant status (TAS) were measured by kits.

RESULTS

HIIT for 6 weeks induced an improvement in performance tests and waist circumference. 6 weeks of HIIT resulted in a decrement, while the last exercise session yielded an increment in RBC deformability. PV and TOS of HIIT groups were decreased on the 6th week.

CONCLUSIONS

Our results demonstrate that, HIIT in addition to the routine exercise program is beneficial for improving performance and blood fluidity as well as decreasing oxidative stress in basketball players. Therefore, HIIT seems as an efficient training strategy for highly-trained individuals.

Red Blood Cell Distribution Width, Erythrocyte Indices, and Elongation Index at Baseline in a Group of Trained Subjects

BACKGROUND

Regular exercise elicits adaptive changes in several organs and physiological processes, including erythrocyte properties.

METHODS

In a group of 79 subjects (62 men and 17 women; mean age 31.37 ± 10.19 years) who trained several times a week as they practiced amateur sports, we evaluated the elongation index, markers of erythrocyte deformability, red blood cell distribution width (RDW), indicators of erythrocyte anisocytosis, hematocrit, hemoglobin, and the main erythrocyte indices (MCV, MCH, MCHC) in basal conditions.

RESULTS

In comparison with a group of healthy, but not training, volunteers, the values of the elongation index, and not the RDW, are increased, and this datum is accompanied by an increase in MCV and MCHC, likely related to an increased presence of circulating young erythrocytes in training subjects. We also divided the same group according to the median of the VO2max, observing that the subgroup above the median shows both an increase in the elongation index values and a decrease in MCH and MCHC.

CONCLUSIONS

In trained subjects, there is no correlation between the values of the elongation index and the RDW, while the interrelations among the elongation index, RDW, and main erythrocyte indices appear to be of particular interest and of a certain complexity.

Sub-Fractions of Red Blood Cells Respond Differently to Shear Exposure Following Superoxide Treatment

Simple Summary

Deformation of red blood cells (RBCs) is essential in order to pass through the smallest blood vessels. This cell function is impaired in the presence of high levels of free radicals and shear stress that highly exceeds the physiological range. In contrast, shear stress within the physiological range positively affects RBC function. RBCs are a heterogeneous cell population in terms of RBC age with different RBC deformability described for young and old RBCs, but whether these different sub-populations tolerate mechanical and oxidative stress to the same extent remains unknown. The results of the present investigation revealed lower RBC deformability of old RBCs compared to young RBCs and comparable reductions in RBC deformability of the sub-populations caused by free radicals. Physiological shear stress did not further affect free radical content within the RBCs and reversed the deleterious effects of free radicals on RBC deformability of old RBCs only by improving RBC deformability. The changes were aimed to be explained by changes in the formation of nitric oxide (NO), but outputs of NO generation appeared dependent on cell age. These novel findings highlight a yet less-described complex relation between shear stress, free radicals, and RBC mechanics.

Abstract

Red blood cell (RBC) deformability is an essential component of microcirculatory function that appears to be enhanced by physiological shear stress, while being negatively affected by supraphysiological shears and/or free radical exposure. Given that blood contains RBCs with non-uniform physical properties, whether all cells equivalently tolerate mechanical and oxidative stresses remains poorly understood. We thus partitioned blood into old and young RBCs which were exposed to phenazine methosulfate (PMS) that generates intracellular superoxide and/or specific mechanical stress. Measured RBC deformability was lower in old compared to young RBCs. PMS increased total free radicals in both sub-populations, and RBC deformability decreased accordingly. Shear exposure did not affect reactive species in the sub-populations but reduced RBC nitric oxide synthase (NOS) activation and intriguingly increased RBC deformability in old RBCs. The co-application of PMS and shear exposure also improved cellular deformability in older cells previously exposed to reactive oxygen species (ROS), but not in younger cells. Outputs of NO generation appeared dependent on cell age; in general, stressors applied to younger RBCs tended to induce S-nitrosylation of RBC cytoskeletal proteins, while older RBCs tended to reflect markers of nitrosative stress. We thus present novel findings pertaining to the interplay of mechanical stress and redox metabolism in circulating RBC sub-populations.

High-intensity interval training irrespective of its intensity improves markers of blood fluidity in hypertensive patients

Aim: The present study examined and compared the effects of two different HIIT (High-intensity interval training) protocols on markers of blood fluidity in hypertensive patients.Methods: Thirty hypertensive (stage 1, systolic BP >140 and diastolic BP>90 mmHg) patients (age, 47.96 ± 3.20 yrs), were randomly allocated to short-duration HIIT (SDHIIT, n = 10), long-duration HIIT (LDHIIT, n = 10), and control (n = 10) groups. After 2 weeks of continuous mild training, patients in SDHIIT group performed 8 weeks of HIIT included 27 min HIIT that encompassed 27 repetitions of 30 s activity at 80%-100% of VO₂peak interspersed by 30 s passive/active (10%-20% of VO₂peak) recovery, while, patients in LDHIIT group performed 8 weeks of HIIT (32 min per session) included 4 repetitions of 4 min activity at 75%-90% of VO₂peak interspersed by 4 min passive/active (15%-30% of VO₂peak) recovery. Two blood samples were taken before and after training and were analyzed for hemorheological variables.Results: Significant (P < .05) reductions in systolic blood pressure (SBP), blood and plasma viscosity, fibrinogen concentration and red blood cell (RBC) aggregation (8-12%) were found following two training protocols (P < .05), though, the differences between adaptations were not statistically significant (P > .05). In addition, HIIT protocols increased RBC deformability significantly (P < .05), with no significant differences being observed between two protocols.Conclusion: It is concluded that HIIT training reduces SBP and markers of blood fluidity in patients with stage 1 hypertension irrespective of the HIIT intensity and duration. Therefore, this type of exercise training could be prescribed for improving the blood fluidity markers in hypertensive patients.

Impact of A Six Week Training Program on Ventilatory Efficiency, Red Blood Cell Rheological Parameters and Red Blood Cell Nitric Oxide Signaling in Young Sickle Cell Anemia Patients: A Pilot Study

Patients with sickle cell anemia (SCA) show impaired ventilatory efficiency, altered blood rheology, high levels of oxidative/nitrosative stress and enhanced hemolysis with large amounts of circulating free hemoglobin, which reduces nitric oxide (NO) bioavailability. The aim of the study was to investigate whether physical exercise could improve these physiological and biological markers described to contribute to SCA pathophysiology. Twelve SCA patients participated in a controlled six weeks training program with moderate volume (two sessions per week with 15–30 min duration per session) and intensity (70% of the first ventilatory threshold). Parameters were compared before (T0) and after (T1) training. Daily activities were examined by a questionnaire at T0 and one year after the end of T1. Results revealed improved ventilatory efficiency, reduced nitrosative stress, reduced plasma free hemoglobin concentration, increased plasma nitrite levels and altered rheology at T1 while no effect was observed for exercise performance parameters or hematological profile. Red blood cell (RBC) NO parameters indicate increased NO bioavailability which did not affect RBC deformability. Participants increased their daily life activity level. The data from this pilot study concludes that even low intensity activities are feasible and could be beneficial for the health of SCA patients.

Influence of Whole-Body Electrostimulation on the Deformability of Density-Separated Red Blood Cells in Soccer Players

Red blood cell nitric oxide synthase (RBC-NOS) dependent NO production positively affects RBC deformability which is known to improve oxygen supply to the working tissue. Whole-body electrostimulation (WB-EMS) has been shown to improve maximum strength, sprinting and jumping performance, and to increase deformability in elite soccer players during the season. The aim of the present study was to investigate whether WB-EMS affects RBC turnover which might affect overall deformability of circulating RBC by rejuvenation of the RBC population and if this might be related to improved endurance capacity. Thirty male field soccer players were assigned in either a WB-EMS group (EG, n = 10), a training group (TG, n = 10), or a control group (CG, n = 10). EG performed 3 × 10 squat jumps superimposed with WB-EMS twice per week in concurrent to 2-4 soccer training sessions and one match per week. TG only performed 3 × 10 squat jumps without EMS in addition to their soccer routine and the CG only performed the usual soccer training and match per week. Subjects were tested before (Baseline) and in week 7 (wk-7), with blood sampling before (Pre), 15-30 min after (Post), and 24 h after (24 h post) the training. Endurance capacity was determined before and directly after the training period. The key findings of the investigation indicate an increase in young RBC in the EG group along with improved overall RBC deformability, represented by decreased SS1/2:EImax Ratio. Analysis of the different RBC subfractions revealed improved RBC deformability of old RBC during study period. This improvement was not only observed in the EG but also in TG and CG. Changes in RBC deformability were not associated to altered RBC-NOS/NO signaling pathway. Endurance capacity remained unchanged during study period. In summary, the effect of WB-EMS on RBC physiology seems to be rather low and results are only in part comparable to previous findings. According to the lower training volume of the present study it can be speculated that the soccer specific training load in addition to the WB-EMS was too low to induce changes in RBC physiology.

Comparisons of Blood Parameters, Red Blood Cell Deformability and Circulating Nitric Oxide Between Males and Females Considering Hormonal Contraception: A Longitudinal Gender Study

Red blood cell (RBC) deformability is an important determinant of the microcirculation. It is influenced by various hematological parameters but also by nitric oxide (NO) which is produced in RBC from L-arginine by RBC-NO synthase. Longitudinal studies on blood profile, deformability at rest and NO levels but also differences between males and females (±hormonal contraception; HC) are less known so far. The study thus aimed to investigate RBC deformability, RBC NO species (nitrite, RxNO), RBC L-arginine concentration and basal blood parameters in males and females (±HC) as a function of time. RBC deformability was measured at rest once per week and the remaining parameters were measured once per month, respectively. A second experiment aimed to daily measure RBC deformability and 17β-estradiol in Female ± HC during a whole menstruation cycle to investigate a possible relation of the two parameters. Measured parameters showed low week-to-week variation and remained constant during study period. However, RBC deformability increased in Female + HC during study period possibly because of increasing training volume of the participants. Overall, results indicate gender differences in hematological parameters with higher RBC parameters (RBC count, hematocrit, hemoglobin concentration) in males compared to females. Differences were also observed between the female groups with Females - HC showing lower number of RBC but higher MCV and hematocrit compared to Females + HC. RBC deformability was highest in Females - HC which might be related to permanent higher estradiol levels and/or higher RBC NO levels because RBC nitrite and RBC RxNO concentrations were also highest in Females-HC. Results of the second experiment also suggest higher RBC deformability in Female - HC because of higher estradiol concentrations. L-arginine levels known to be related to RBC NO production were comparable in all groups. In conclusion, hematological, hemorheological and NO related parameters show gender differences. In particular, RBC deformability is affected by training volume and RBC estradiol concentrations. The results add new information on the complex regulation of RBC function which might help to better understand the role of RBC in the microcirculation.