Exercise, training and red blood cell turnover

Recovery during Successive 120-min Football Games: Results from the 120-min Placebo/Carbohydrate Randomized Controlled Trial

PURPOSE

This study aimed to examine the recovery kinetics (i.e., time-dependent changes) of performance-related variables between two 120-min male football games performed 3 d apart with and without carbohydrate supplementation.

METHODS

Twenty male players (20 ± 1 yr; body fat, 14.9% ± 5.1%; maximal oxygen consumption, 59.4 ± 3.7 mL·kg -1 ·min -1 ) participated in two 120-min football games (G1, G2) according to a randomized, two-trial, repeated-measures, crossover, double-blind design. Participants received carbohydrate/placebo supplements during recovery between games. Field activity was monitored during the games. Performance testing and blood sampling were performed before and at 90 and 120 min of each game. Muscle biopsies were collected at baseline and at 90 and 120 min of G1 and pre-G2.

RESULTS

Compared with G1, G2 was associated with reduced total distance (10,870 vs 10,685 m during 90 min and 3327 vs 3089 m during extra 30 min; P = 0.007-0.038), average (6.7 vs 6.2 km/h during extra 30-min game-play; P = 0.007) and maximal speed (32.2 vs 30.2 km/h during 90 min and 29.0 vs 27.9 km/h during extra 30 min; P < 0.05), accelerations/decelerations ( P < 0.05), and mean heart rate ( P < 0.05). Repeated sprint ability ( P < 0.001), jumping ( P < 0.05), and strength ( P < 0.001) performance were compromised before and during G2. Muscle glycogen was not restored at G2 baseline ( P = 0.005). Extended game-play reduced lymphocyte, erythrocyte counts, hematocrit, hemoglobin, reduced glutathione ( P < 0.05) and increased delayed onset of muscle soreness, creatine kinase activity, blood glycerol, ammonia, and protein carbonyls ( P < 0.05) before and during G2. Pax7 + ( P = 0.004) and MyoD + cells ( P = 0.019) increased at baseline G2. Carbohydrate supplementation restored performance and glycogen, reduced glycerol and delayed onset of muscle soreness responses, and increased leukocyte counts and Pax7 + and MyoD + cells.

CONCLUSIONS

Results suggest that extended football games induce a prolonged recovery of performance, which may be facilitated by carbohydrate supplementation during a congested game fixture.

Erythrocyte metabolism

Our aim is to present an updated overview of the erythrocyte metabolism highlighting its richness and complexity. We have manually collected and connected the available biochemical pathways and integrated them into a functional metabolic map. The focus of this map is on the main biochemical pathways consisting of glycolysis, the pentose phosphate pathway, redox metabolism, oxygen metabolism, purine/nucleoside metabolism, and membrane transport. Other recently emerging pathways are also curated, like the methionine salvage pathway, the glyoxalase system, carnitine metabolism, and the lands cycle, as well as remnants of the carboxylic acid metabolism. An additional goal of this review is to present the dynamics of erythrocyte metabolism, providing key numbers used to perform basic quantitative analyses. By synthesizing experimental and computational data, we conclude that glycolysis, pentose phosphate pathway, and redox metabolism are the foundations of erythrocyte metabolism. Additionally, the erythrocyte can sense oxygen levels and oxidative stress adjusting its mechanics, metabolism, and function. In conclusion, fine-tuning of erythrocyte metabolism controls one of the most important biological processes, that is, oxygen loading, transport, and delivery.

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.

Empowering frail older adults: multicomponent elastic-band exercises and BCAA supplementation unleash physical health and preserve haematological biomarkers

The effectiveness of Branched Chain Amino Acids (BCAAs) supplementation on enhancing exercise performance in both young and older adults remains a topic of debate. Recent research suggests that BCAAs combined with regular exercise might have an impact on human erythropoiesis, blood dynamics, and iron homeostasis. Given the increasing longevity of the global population, it is crucial to investigate the potential benefits of BCAA supplementation and regular exercise as non-pharmacological interventions for improving the overall health of frail older adults. To assess the influence of a 40-week multicomponent exercise intervention (MEP) combined BCCA supplementation on the haematological indicators of frail older adults (83-93 years old) residing in nursing homes. A prospective, naturalistic, controlled clinical trial employing an intervention-washout-intervention was conducted for this purpose. The study included four experimental groups: MEP plus BCAA supplementation (MEP + BCAA, n = 8), MEP only (n = 7), BCAA supplementation only (n = 7), and control group non exercising (CG, n = 13). Fried's physical frailty (PF) protocol was employed to stratify the participants. Additionally, the assessment included the evaluation of nutritional status, comorbidities, and anthropometric measurements. Among the several haematological markers examined, only mean cellular Haemoglobin Concentration (MCH) [F = 4.09; p < 0.03] and Mean Cell haemoglobin Concentration (MCHC) [F = 10, 323; p < 0,0001] showed significant effects of time group. Our findings demonstrate that a long-term intervention with BCAA plus MEP did not lead to significant alterations in the haematological profile. An 8-week withdrawal from interventions did not affect the frailty status in the MEP and MEP + BCAA groups, whereas the control group exhibited an increase in PF status. The findings, demonstrating the potential pro-immune effect and maintenance of MCH and MCHC levels, highlight the relevance of incorporating exercise and nutritional strategies to promote healthy aging. This study contributes to the achievement of the United Nations Sustainable Development Goals 3 (good health and well-being) and 10 (reduced Inequalities) for all.

CD71+ RBCs: A potential immune mediator in transfusion

Donor - recipient sex - mismatched transfusion is associated with increased mortality. The mechanisms for this are not clear, but it may relate to transfusion-related immunomodulation. Recently, CD71⁺ erythroid cells (CECs), including reticulocytes (CD71⁺ RBCs) and erythroblasts, have been identified as potent immunoregulatory cells. The proportion of CD71⁺ RBCs in the peripheral blood is sufficient to play a potential immunomodulatory role. Differences in the quantity of CD71⁺ RBCs are dependent on blood donor sex. The total number of CD71⁺ RBCs in red cell concentrates is also affected by blood manufacturing methods, and storage duration. As a component of the total CECs, CD71⁺ RBCs can affect innate and adaptive immune cells. Phagocytosed CECs directly reduce TNF-α production from macrophages. CECs can also suppress the production of TNF-α production from antigen presenting cells. Moreover, CECs can suppress T cell proliferation thorough immune mediation and / or direct cell-to-cell interactions. Different in their biophysical features compared to mature RBCs, blood donor CD71⁺ RBCs may be preferential targets for the macrophages. This report summarizes the currently literature supporting an important role for CD71⁺ RBCs in adverse transfusion reactions including immune mediation and sepsis.

Effects of Rowing on Rheological Properties of Blood

The aim of this study was to analyze the selected hematological and rheological indices in female rowers during the competitive season. The study included 10 female rowers (aged 21.2 ± 2.6) and the control group consisted of 10 woman of corresponding age (non-athletes). The examination of athletes took place two times: at the beginning of the season during high endurance low intensity training period in January (baseline) and at the end of the competitive season in October (after). Blood samples taken from all woman were analyzed for hematological and rheological parameters. The training period of rowers during the 10 months resulted in decrease in red blood cell count and RBC deformability, in contrast to an improvement in some rheological functions such a decrease in fibrinogen concentration, plasma viscosity and aggregation index. The training program practice in rowing modulated some hematological and rheological indices. Some of them positively influenced the cardiovascular system and reduced potential risks connected with hard training and dehydration, but others may have followed from overtraining or not enough relaxation time between training units.

Hematological and Biochemical Responses of Donkeys (Equus asinus) to Packing and Trekking During the Hot-Dry Season

The study aimed to evaluate effects of packing (load-carrying) and trekking on hematological and biochemical parameters in donkeys during the hot-dry season. Ten pack donkeys, aged 2-3 years, weighing 93 ± 2.7 kg were enrolled in the study and randomly divided into two groups of five animals each. Group 1 donkeys were subjected to packing + trekking while group 2 trekked only. All the donkeys trekked 20 km thrice, 1-day apart. Blood was collected before and after packing or trekking for hematological evaluation; and serum analyzed for electrolyte concentrations, and aspartate aminotransferase, creatine kinase and lactate dehydrogenase activities. Temperature-humidity index pre and postpacking was 70.00 ± 0.1 and 79.67 ± 0.3, respectively. The packed cell volume (30.93 ± 1.1%) was higher (P < .05) before packing than postpacking value (27.83 ± 0.7%) in group 1 donkeys. Hemoglobin concentration (9.01 ± 0.3 g/dL) decreased (P < .05) after trekking (7.81 ± 0.1 g/dL) in group 2 donkeys. Neutrophil count increased (P < .05) in group 1 donkeys after packing (from 8.63 ± 0.9 × 10⁹/L to 10.59 ± 1.2 × 10⁹/L). Lymphocyte count (8.58 ± 0.8 × 10⁹/L) decreased (P < .05), compared to postpacking (5.23 ± 0.5 × 10⁹/L) in group 1 donkeys. Postpacking neutrophil/lymphocyte ratio in group 1 donkeys (2.33 ± 0.4) was higher (P < .05) than in group 2 donkeys (1.31 ± 0.3). Electrolyte concentrations and enzyme activities did not change significantly. In conclusion, packing + trekking was more stressful to the donkeys than trekking only, evidenced by postpacking increased neutrophil count, neutrophil/lymphocyte ratio and phosphate ion concentration, but decreased lymphocyte count. If this stress is not mitigated, the performance of pack donkeys during hot-dry season may not be optimum.

Donor sex, pre-donation hemoglobin, and manufacturing affect CD71+ cells in red cell concentrates

BACKGROUND

Circulating CD71⁺ red blood cells (RBCs) have been reported to play an immunomodulatory role in vivo, which may contribute to adverse donor-recipient sex-mismatched transfusion outcomes. However, it is not clear how CD71⁺ RBC quantity in red cell concentrates (RCCs) is affected by manufacturing methods and donor factors such as donor sex, donor age, pre-donation hemoglobin (Hb), venous Hb (Hb_v ) levels, and donation frequency.

METHODS

We determined CD71⁺ RBCs and Hb levels in whole blood (WB) from healthy donors (42 male/38 female). Using small-scale red cell filtration (RCF) and whole blood filtration (WBF) methods, leukoreduced RCCs were processed from WB samples (n = 6) and the CD71⁺ RBCs were determined at days 1, 7, and 28. We examined uni- and multivariate associations among CD71⁺ RBCs, donor factors, and manufacturing method.

RESULTS

Male donors had a higher CD71⁺ RBC concentration than females (p < .001), especially male donors aged 17-50 years with 1 or 2 WB donations over the previous 12 months. Donors with a Hb_v above 155 g/L had a higher CD71⁺ RBC concentration than an Hb_v level below 140 g/L (p < .05). There was a positive correlation between pre-donation Hb and CD71⁺ RBC concentration (Pearson r = 0.41). WBF RCCs had a higher total number of CD71⁺ RBCs than RCF-produced RCCs on day 1 (p < .05).

DISCUSSION

RCCs have variable numbers of CD71⁺ RBCs. This makes understanding the impact of donor factors and manufacturing methods on the immunomodulatory effect of CD71⁺ RBCs critical in exploring donor-recipient sex-mismatched transfusions.

Concerted phenotypic flexibility of avian erythrocyte size and number in response to dietary anthocyanin supplementation

BACKGROUND

Endurance flight impose substantial oxidative costs on the avian oxygen delivery system. In particular, the accumulation of irreversible damage in red blood cells can reduce the capacity of blood to transport oxygen and limit aerobic performance. Many songbirds consume large amounts of anthocyanin-rich fruit, which is hypothesized to reduce oxidative costs, enhance post-flight regeneration, and enable greater aerobic capacity. While their antioxidant benefits appear most straightforward, the effects of anthocyanins on blood composition remain so far unknown. We fed thirty hand-raised European starlings (Sturnus vulgaris) two semisynthetic diets (with or without anthocyanin supplement) and manipulated the extent of flight activity in a wind tunnel (daily flying or non-flying for over two weeks) to test for their interactive effects on functionally important haematological variables.

RESULTS

Supplemented birds had on average 15% more and 4% smaller red blood cells compared to non-supplemented individuals and these diet effects were independent of flight manipulation. Haemoglobin content was 7% higher in non-supplemented flying birds compared to non-flying birds, while similar haemoglobin content was observed among supplemented birds that were flown or not. Neither diet nor flight activity influenced haematocrit.

CONCLUSION

The concerted adjustments suggest that supplementation generally improved antioxidant protection in blood, which could prevent the excess removal of cells from the bloodstream and may have several implications on the oxygen delivery system, including improved gas exchange and blood flow. The flexible haematological response to dietary anthocyanins may also suggest that free-ranging species preferentially consume anthocyanin-rich fruits for their natural blood doping, oxygen delivery-enhancement effects.

Effects of melatonin on hematologic and biochemical changes, and the effects on circadian rhythm on hematologic changes in donkeys (Equus asinus) subjected to packing during the hot-dry season

BACKGROUND

Melatonin is a hormone with antioxidant and anti-inflammatory properties and may alleviate the effects of stress on hematologic and biochemical analytes in working donkeys that pack (load-carry).

OBJECTIVES

We aimed to evaluate the effects of melatonin administration on hematologic and biochemical responses in donkeys subjected to packing during the hot-dry season. We also examined its effects on circadian rhythms.

METHODS

Ten male Nubian pack donkeys with (Packing + Melatonin; P + M) and without melatonin (Packing-Melatonin; P-M) administration were included. Blood samples were collected before, immediately after (15 min), and from 16 h to over 27-h postpacking at 3-h intervals for hematologic and total protein analyses. Serum from blood samples collected before and immediately after packing was analyzed for muscle enzyme activities and electrolyte concentrations. Student's t-test, one-way ANOVA, and online cosinor analysis were used for statistical analyses.

RESULTS

Packed cell volumes (PCVs) of the P + M donkeys did not differ before and after packing. However, for the P-M donkeys, values before packing (30.20 ± 0.8%) were higher than those (26.87 ± 0.5%) after packing. The hematologic values recorded in the P + M donkeys were higher than those in the P-M donkeys, especially during the scotophase (P ˂ 0.05). The mesor PCV, hemoglobin (Hb), and red blood cell (RBC) values for the P + M donkeys were significantly (P ˂ 0.05) higher than those in the P-M donkeys. Lactate dehydrogenase (LDH) activity was not different before (289.40 ± 60.8 U/L) or after packing (323.20 ± 36.0 U/L) in P + M donkeys, but the activity was significantly (P ˂ 0.05) higher postpacking than prepacking in the P-M donkeys (294.20 ± 66.9 U/L and 513.40 ± 68.5 U/L, respectively). The relationships between the meteorologic parameters and PCV, Hb, and RBC concentrations in the P + M donkeys were significantly negative (P ˂ 0.05).

CONCLUSIONS

Melatonin prevented a decrease in PCV and increase in LDH activity immediately after packing compared with non-treated donkeys. There was a marked effect during the scotophase on PCV, Hb, and RBC concentrations. The circadian parameters indicated a significant effect of melatonin on the rhythmicity of the PCV, Hb, and RBC concentration in the treated donkeys. Melatonin administration may reduce the risk of adverse effects of environmental stress and stress due to packing in donkeys during the hot-dry season.

Influence of iron supplementation on fatigue, mood states and sweating profiles of healthy non-anemic athletes during a training exercise: A double-blind, randomized, placebo-controlled, parallel-group study

Iron is specifically important to athletes, and attention has grown to the association between sports performance and iron regulation in the daily diets of athletes. The study presents new insights into stress, mood states, fatigue, and sweating behavior among the non-anemic athletes with sweating exercise habits who consumed a routine low dose (3.6 mg/day) of iron supplementation. In this double-blind, randomized, placebo-controlled, parallel-group study, both non-anemic male (N = 51) and female (N = 42) athletes were supplemented either with a known highly bioavailable iron formulation (SunActive® Fe) or placebo during the follow-up training exercise period over four weeks at their respective designated clinical sites. The effect of oral iron consumption was examined on fatigue, stress profiles, as well as the quality of life using the profile of mood state (POMS) test or a visual analog scale (VAS) questionnaire, followed by an exercise and well-being related fatigue-sweat. Also, their monotonic association with stress biomarkers (salivary α-amylase, salivary cortisol, and salivary immunoglobulin A) were determined using spearman's rank correlation coefficient test. Repeated measure multivariate analysis of variance (group by time) revealed that the total mood disturbance (TMD) score was significantly lower (P = 0.016; F = 6.26) between placebo and iron supplementation groups over the four weeks study period among female athletes. Also, a significant reduction in tired feeling/exhaustion after the exercise (P = 0.05; F = 4.07) between the placebo and iron intake groups was noticed. A significant within-group reduction (P ≤ 0.05) was noticed in the degree of sweat among both male and female athletes after 2 and 4 weeks of iron supplementation, while athletes of the placebo intake group experienced a non-significant within-group reduction in the degree of sweat. Overall, the result indicates routine use of low dose (3.6 mg/day) iron supplementation is beneficial for non-anemic endurance athletes to improve stress, mood states, subjective fatigue, and sweating conditions.

L-Glutamine is better for treatment than prevention in exhaustive exercise

Introduction: Glutamine is known as the richest nonessential amino acid in the human body. The intake of glutamine is not only beneficial to nutrition but also reported to enhance inflammation reducing bioactivity in exercise. Although studies have demonstrated that glutamine is beneficial for exercise, the optimal intake timing remains unclear. This study examined whether the effects of glutamine on tissue damage and physiology differ between intake timings. Methods: Rats were divided into without L-glutamine supplementation (vehicle), with L-glutamine before exhaustive exercise (prevention), and with L-glutamine after exhaustive exercise (treatment) groups. Exhaustive exercise was induced by treadmill running and L-glutamine was given by oral feeding. The exhaustive exercise began at a speed of 10 miles/min and increased in increments of 1 mile/min, to a maximum running speed of 15 miles/min with no incline. The blood samples were collected before exhaustive exercise, 12 h and 24 h after exercise to compare the creatine kinase isozyme MM (CK-MM), red blood cell count and platelet count. The animals were euthanized on 24 h after exercise, and tissue samples were collected for pathological examination and scored the severity of organ injury from 0 to 4. Results: The CK-MM was elevated gradually after exercise in the vehicle group; however, CK-MM was decreased after L-glutamine supplementation in the treatment group. The treatment group had higher red blood cell count and platelet count than the vehicle and prevention group after exercise. In addition, the treatment group had less tissue injury in the cardiac muscles, and kidneys than prevention group. Conclusion: The therapeutic effect of L-glutamine after exhaustive exercise was more effective than preventive before exercise.

MiRNA-based “fitness score” to assess the individual response to diet, metabolism, and exercise

Background

Regular, especially sustained exercise plays an important role in the prevention and treatment of multiple chronic diseases. Some of the underlying molecular and cellular mechanisms behind the adaptive response to physical activity are still unclear, but recent findings suggest a possible role of epigenetic mechanisms, especially miRNAs, in the progression and management of exercise-related changes. Due to the combination of the analysis of epigenetic biomarkers (miRNAs), the intake of food and supplements, and genetic dispositions, a “fitness score” was evaluated to assess the individual response to nutrition, exercise, and metabolic influence.

Methods

In response to a 12-week sports intervention, we analyzed genetic and epigenetic biomarkers in capillary blood from 61 sedentary, healthy participants (66.1% females, 33.9% males, mean age 33 years), including Line-1 methylation, three SNPs, and ten miRNAs using HRM and qPCR analysis. These biomarkers were also analyzed in a healthy, age- and sex-matched control group (n, 20) without intervention. Food frequency intake, including dietary supplement intake, and general health questionnaires were surveyed under the supervision of trained staff.

Results

Exercise training decreased the expression of miR-20a-5p, −22-5p, and −505-3p (p < 0.02) and improved the “fitness score,” which estimates eight different lifestyle factors to assess, nutrition, inflammation, cardiovascular fitness, injury risk, regeneration, muscle and hydration status, as well as stress level. In addition, we were able to determine correlations between individual miRNAs, miR-20a-5p, −22-5p, and −101-3p (p < 0.04), and the genetic predisposition for endurance and/or strength and obesity risk (ACE, ACTN3, and FTO), as well as between miRNAs and the body composition (p < 0.05). MiR-19b-3p and −101-3p correlated with the intake of B vitamins. Further, miR-19b-3p correlated with magnesium and miR-378a-3p with iron intake (p < 0.05).

Conclusions

In summary, our results indicate that a combined analysis of several biomarkers (miRNAs) can provide information about an individual’s training adaptions/fitness, body composition, nutritional needs, and possible recovery. In contrast to most studies using muscle biopsies, we were able to show that these biomarkers can also be measured using a minimally invasive method.

Autologous Blood Doping Induced Changes in Red Blood Cell Rheologic Parameters, RBC Age Distribution, and Performance

Simple Summary

Autologous blood doping (ABD) refers to the artificial increase in circulating red blood cell (RBC) mass by sampling, storage, and transfusion of one’s own blood. It is assumed that some athletes apply this prohibited technique to improve oxygen transport capacity and thus exercise performance. The primary aim of this study was to test whether RBC rheological and associated parameters significantly change due to ABD with the consideration of whether this type of measurement might be suitable for detecting ABD. Further, it was assessed whether those changes are translated into indices of endurance performance. Eight males underwent an ABD protocol combined with several blood parameter measurements and two exercise tests (pre and post transfusion). Results of this investigation suggest a change in the distribution of age-related RBC sub-populations and altered deformability of total RBC as well as of the respective sub-populations. Further, the identified changes in RBC also appear to improve sports performance. In conclusion, these data demonstrate significant changes in hematological and hemorheological parameters, which could be of interest in the context of new methods for ABD detection. However, additional research is needed with larger and more diverse study groups to widen the knowledge gained by this study.

Abstract

Autologous blood doping (ABD) refers to the transfusion of one’s own blood after it has been stored. Although its application is prohibited in sports, it is assumed that ABD is applied by a variety of athletes because of its benefits on exercise performance and the fact that it is not detectable so far. Therefore, this study aims at identifying changes in hematological and hemorheological parameters during the whole course of ABD procedure and to relate those changes to exercise performance. Eight healthy men conducted a 31-week ABD protocol including two blood donations and the transfusion of their own stored RBC volume corresponding to 7.7% of total blood volume. Longitudinal blood and rheological parameter measurements and analyses of RBC membrane proteins and electrolyte levels were performed. Thereby, responses of RBC sub-populations—young to old RBC—were detected. Finally, exercise tests were carried out before and after transfusion. Results indicate a higher percentage of young RBC, altered RBC deformability and electrolyte concentration due to ABD. In contrast, RBC membrane proteins remained unaffected. Running economy improved after blood transfusion. Thus, close analysis of RBC variables related to ABD detection seems feasible but should be verified in further more-detailed studies.

Changes in blood rheological properties and biochemical markers after participation in the XTERRA Poland triathlon competition

The importance of physical activity in preventing chronic cardiovascular and metabolic diseases and the role of exercise as an adjunct therapy are widely recognized. Triathlon is a typically endurance discipline. Prolonged and intensive exercise is known to cause changes in blood rheological properties and biochemical markers; sometimes athletes participating in strenuous competitions need medical attention. To understand the phenomena occurring in the body in such situations, we decided to study participants’ biomarkers after the XTERRA Poland 2017 triathlon competition. The study involved 10 triathletes. The XTERRA Poland 2017 event comprised 1500-m swimming, 36-km cycling, and 10-km mountain running. Blood samples were collected 2 days before, immediately after, and 16 h after the competition. Immediately after the race, white blood cells count, platelets, and uric acid levels were significantly (P < 0.001) increased; haematocrit, Na⁺, Cl^–, and IgA were decreased. On the following day, Na⁺, Cl^–, and C-reactive protein levels were significantly (P < 0.001) increased; white blood cells count, red blood cells count, haemoglobin, haematocrit, mean corpuscular volume, platelets, IgG, and IgA were decreased. Assessing rheological parameters such as erythrocyte deformability and aggregation is useful for monitoring adverse effects of intensive and exhaustive exercise. The study illustrates the change in blood rheological properties and biochemical markers after intensive physical effort. Despite these differences, the indicators were within the reference range for the general population, which may demonstrate normal body function in the studied triathletes.

Benefits on Hematological and Biochemical Parameters of a High-Intensity Interval Training Program for a Half-Marathon in Recreational Middle-Aged Women Runners

(1) Background: half-marathon races are popular among recreational runners, with increases in participation among middle-aged and women. We aimed to determine the effects of two half-marathon training programs on hematological and biochemical markers in middle-aged female recreational runners; (2) Methods: ten women (40 ± 7 years) followed moderate intensity continuous training (MICT), based on running volume below 80% V˙O₂max, and another ten women followed high intensity interval training (HIIT) at 80%–100% V˙O₂max, with less volume, and combined with eccentric loading exercise. Hematology, plasma osmolality, and plasma markers of metabolic status, muscle damage, inflammatory, and oxidative stress were measured before (S1) and after (S2) training and 24 h after the half-marathon (S3); (3) Results: both training programs had similar moderate effects at S2. However, the acute response at S3 induced different alterations. There was a greater decrease in cholesterol and triglyceride levels in MICT and reductions in markers of damage and inflammation in HIIT. Greater variability in some plasma markers at S3 in MICT suggests that there is inter-individual variability in the response to training; (4) Conclusions: HIIT led to better adaptation to the competition maybe because of the repeated exposure to higher oxygen consumption and eccentric loading exercise.

Recommendations and Nutritional Considerations for Female Athletes: Health and Performance

Optimal nutrition is an important aspect of an athlete’s preparation to achieve optimal health and performance. While general concepts about micro- and macronutrients and timing of food and fluids are addressed in sports science, rarely are the specific effects of women’s physiology on energy and fluid needs highly considered in research or clinical practice. Women differ from men not only in size, but in body composition and hormonal milieu, and also differ from one another. Their monthly hormonal cycles, with fluctuations in estrogen and progesterone, have varying effects on metabolism and fluid retention. Such cycles can change from month to month, can be suppressed with exogenous hormones, and may even be manipulated to capitalize on ideal timing for performance. But before such physiology can be manipulated, its relationship with nutrition and performance must be understood. This review will address general concepts regarding substrate metabolism in women versus men, common menstrual patterns of female athletes, nutrient and hydration needs during different phases of the menstrual cycle, and health and performance issues related to menstrual cycle disruption. We will discuss up-to-date recommendations for fueling female athletes, describe areas that require further exploration, and address methodological considerations to inform future work in this important area.

Skeletal muscle heme oxygenase-1 activity regulates aerobic capacity

Physical exercise has profound effects on quality of life and susceptibility to chronic disease; however, the regulation of skeletal muscle function at the molecular level after exercise remains unclear. We tested the hypothesis that the benefits of exercise on muscle function are linked partly to microtraumatic events that result in accumulation of circulating heme. Effective metabolism of heme is controlled by Heme Oxygenase-1 (HO-1, Hmox1), and we find that mouse skeletal muscle-specific HO-1 deletion (Tam-Cre-HSA-Hmox1^fl/fl) shifts the proportion of muscle fibers from type IIA to type IIB concomitant with a disruption in mitochondrial content and function. In addition to a significant impairment in running performance and response to exercise training, Tam-Cre-HSA-Hmox1^fl/fl mice show remarkable muscle atrophy compared to Hmox1^fl/fl controls. Collectively, these data define a role for heme and HO-1 as central regulators in the physiologic response of skeletal muscle to exercise.

Acute Cycling Exercise Induces Changes in Red Blood Cell Deformability and Membrane Lipid Remodeling

Here we describe the effects of a controlled, 30 min, high-intensity cycling test on blood rheology and the metabolic profiles of red blood cells (RBCs) and plasma from well-trained males. RBCs demonstrated decreased deformability and trended toward increased generation of microparticles after the test. Meanwhile, metabolomics and lipidomics highlighted oxidative stress and activation of membrane lipid remodeling mechanisms in order to cope with altered properties of circulation resulting from physical exertion during the cycling test. Of note, intermediates from coenzyme A (CoA) synthesis for conjugation to fatty acyl chains, in parallel with reversible conversion of carnitine and acylcarnitines, emerged as metabolites that significantly correlate with RBC deformability and the generation of microparticles during exercise. Taken together, we propose that RBC membrane remodeling and repair plays an active role in the physiologic response to exercise by altering RBC properties.

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.

Six weeks of dynamic apnoeic training stimulates erythropoiesis but does not increase splenic volume

Purpose

This study examined the influence of dynamic apnoea training on splenic volume and haematological responses in non-breath-hold divers (BHD).

Methods

Eight non-BHD performed ten maximal dynamic apnoeas, four times a week for  six weeks. Splenic volumes were assessed ultrasonically, and blood samples were drawn for full blood count analysis, erythropoietin, iron, ferritin, albumin, protein and osmolality at baseline, 24 h post the completion of each week’s training sessions and seven days post the completion of the training programme. Additionally, blood samples were drawn for haematology at 30, 90, and 180 min post session one, twelve and twenty-four.

Results

Erythropoietin was only higher than baseline (6.62 ± 3.03 mlU/mL) post session one, at 90 (9.20 ± 1.88 mlU/mL, p = 0.048) and 180 min (9.04 ± 2.35 mlU/mL, p = 0.046). Iron increased from baseline (18 ± 3 µmol/L) post week five (23 ± 2 µmol/L, p = 0.033) and six (21 ± 6 µmol/L; p = 0.041), whereas ferritin was observed to be lower than baseline (111 ± 82 µg/L) post week five (95 ± 75 µg/L; p = 0.016), six (84 ± 74 µg/L; p = 0.012) and one week post-training (81 ± 63 µg/L; p = 0.008). Reticulocytes increased from baseline (57 ± 12 × 10⁹/L) post week one (72 ± 17 × 10⁹/L, p = 0.037) and six (71 ± 17 × 10⁹/L, p = 0.021) while no changes were recorded in erythrocytes (p = 0.336), haemoglobin (p = 0.124) and splenic volumes (p = 0.357).

Conclusions

Six weeks of dynamic apnoeic training increase reticulocytes without altering mature erythrocyte concentration and splenic volume.

Does endurance training improve red blood cell aging and hemorheology in moderate-trained healthy individuals?

OBJECTIVE

To examine the impact of a 6-week endurance training on red blood cell (RBC) aging and deformability of healthy participants to detect possible improved hemorheological and performance-related adaptations.

METHODS

A total of 31 participants (17 females and 14 males) performed a 6-week moderate training protocol (three 1-h running sessions per week at 70% of maximal heart rate). Blood was sampled before and after the training. RBCs from each participant were fractioned according to density and age into 4 RBC subfractions. Subfractions were examined for changes of RBC properties, including aging distribution, RBC deformability, RBC microparticles, and phosphatidylserine concentrations. RBC and plasma nitrite levels were measured as indicators of nitric oxide metabolism.

RESULTS

Aerobic performance, peak oxygen consumption, ventilatory thresholds, velocity at the aerobic-anaerobic threshold, and lactate at exhaustion improved after training. The relative amount of both young RBCs and old RBCs increased, and the amount of the main RBC fraction decreased. Phosphatidylserine externalization and RBC-derived microparticles decreased. Overall deformability expressed as shear stress required to achieve half-maximum deformation to theoretical maximal elongation index at infinite shear stress improved in unfractioned RBCs (p < 0.001). Nitrite decreased in total (p = 0.001), young (p < 0.001), main (p < 0.001), and old (p = 0.020) aged RBCs and in plasma (p = 0.002), but not in very old RBCs.

CONCLUSION

These results indicate that non-endurance-trained healthy participants benefit from a regular moderate running training program because performance-related parameters improve and a younger RBC population with improved RBC properties is induced, which might support oxygen supply in the microcirculation.

Iron and zinc homeostases in female rats with physically active and sedentary lifestyles

To determine the effects of repeated physical activity on iron and zinc homeostases in a living system, we quantified blood and tissue levels of these two metals in sedentary and physically active Long-Evans rats. At post-natal day (PND) 22, female rats were assigned to either a sedentary or an active treatment group (n = 10/group). The physically active rats increased their use of a commercially-constructed stainless steel wire wheel so that, by the end of the study (PND 101), they were running an average of 512.8 ± 31.9 (mean ± standard error) min/night. After euthanization, plasma and aliquots of liver, lung, heart, and gastrocnemius muscle were obtained. Following digestion, non-heme iron and zinc concentrations in plasma and tissues were measured using inductively coupled plasma optical emission spectroscopy. Concentrations of both non-heme iron and zinc in plasma and liver were significantly decreased among the physically active rats relative to the sedentary animals. In the lung, both metals were increased in concentration among the physically active animals but the change in zinc did not reach significance. Similarly, tissue non-heme iron and zinc levels were both increased in heart and muscle from the physically active group. It is concluded that repeated physical activity in an animal model can be associated with a translocation of both iron and zinc from sites of storage (e.g. liver) to tissues with increased metabolism (e.g. the lung, heart, and skeletal muscle).

Impact of vigorous effort on blood morphological indicators in triathletes participating in the XTERRA Poland 2017 competition

Purpose: The aim of the study was to determine the influence of participation in the XTERRA Poland 2017 triathlon on blood morphology indicators. Material and methods: The study was performed in a group among 10 triathletes aged 30-40 years. Blood was collected 24 hours before, immediately after , and 16 hours after the competition. Blood morphological indicators were evaluated using the ABXMicros60 analyser. Results: Comparison of the results among the first (24 hours before the competition), second (immediately after the competition), and third assessment (16 hours after the competition) revealed statistically significant changes for WBC [109/l], RBC [1012/l], HGB [g/l], HCT [l/l], MCV [fl] and PLT [109/l]. Conclusions: The intensity of effort in the XTERRA Poland 2017 triathlon competitors was confirmed in the results of blood morphology. Blood counts in those practicing triathlon well characterise the actual scope and direction of exercise changes and allow for the diagnosis of transient adaptive effects. The results of the research confirmed that vigorous physical effort during the triathlon increased leukocyte and platelet counts, but 16 hours after completing the competition, their value was close to baseline level. Most likely, this phenomenon was caused by the intense effort, stress or even eating a large meal before the competition. Analysing the red blood cell system showed a tendency towards decrease in the number of red blood cells, HGB and HCT both after the competition and 16 hours after its completion, which results from increased post-exercise haemolysis or the risk of anaemia.

Dietary intake of heme iron is associated with ferritin and hemoglobin levels in Dutch blood donors: results from Donor InSight

Whole blood donors, especially frequently donating donors, have a risk of iron deficiency and low hemoglobin levels, which may affect their health and eligibility to donate. Lifestyle behaviors, such as dietary iron intake and physical activity, may influence iron stores and thereby hemoglobin levels. We aimed to investigate whether dietary iron intake and questionnaire-based moderate-to-vigorous physical activity were associated with hemoglobin levels, and whether ferritin levels mediated these associations. In Donor InSight-III, a Dutch cohort study of blood and plasma donors, data on heme and non-heme iron intake (mg/day), moderate-to-vigorous physical activity (10 minutes/day), hemoglobin levels (mmol/L) and ferritin levels (μg/L) were available in 2,323 donors (1,074 male). Donors with higher heme iron intakes (regression coefficients (β) in men and women: 0.160 and 0.065 mmol/L higher hemoglobin per 1 mg of heme iron, respectively) and lower non-heme iron intakes (β: -0.014 and -0.017, respectively) had higher hemoglobin levels, adjusted for relevant confounders. Ferritin levels mediated these associations (indirect effect (95% confidence interval) in men and women respectively: 0.074 (0.045; 0.111) and 0.061 (0.030; 0.096) for heme and -0.003 (-0.008;0.001) and -0.008 (-0.013;-0.003) for non-heme). Moderate-to-vigorous physical activity was negatively associated with hemoglobin levels in men only (β: -0.005), but not mediated by ferritin levels. In conclusion, higher heme and lower non-heme iron intake were associated with higher hemoglobin levels in donors, via higher ferritin levels. This indicates that donors with high heme iron intake may be more capable of maintaining iron stores to recover hemoglobin levels after blood donation.

Association Between Anemia and Dementia: A Nationwide, Populationbased Cohort Study in Taiwan

Background:

In addition to the traditional risk predictors, whether anemia is an early biomarker of dementia, needs to be confirmed.

Objective:

This population-based cohort study aimed to investigate the dementia risk in patients with newly diagnosed anemia using data from the Taiwan National Health Insurance Research Database.

Methods:

All newly diagnosed anemia patients (n = 26,343) with no history of stroke hospitalization, central nervous disease other than dementia, psychiatric disorders, traumatic brain injury, major operations, or blood loss diseases, were enrolled. A group of non-anemic controls, 1:4 matched with anemic patients on the basis of demographics and comorbidities, was also included. A competing risk analysis was used to evaluate the dementia risk in anemic patients compared to that of their matched controls.

Results:

The adjusted subdistribution hazard ratio (SHR) of dementia risk in anemic patients was 1.14 (95% confidence interval [CI]: 1.08~1.21, p<0.001). Patients with iron supplements tended to exhibit a lower dementia risk (adjusted SHR: 0.84; 95% CI: 0.75~0.94, p=0.002) compared to patients without iron supplement. A subgroup analysis showed that a positive association between dementia and anemia existed in females, those aged 70 years and older, and patients without hypertension, diabetes, or hyperlipidemia.

Conclusion:

The present population-based cohort study identified that newly diagnosed anemia is a risk factor for dementia and also that iron supplementation was able to reduce the risk of dementia in people with iron deficiency anemia.

Non-invasive characterization of human bone marrow stimulation and reconstitution by cell-free messenger RNA sequencing

Circulating cell-free mRNA (cf-mRNA) holds great promise as a non-invasive diagnostic biomarker. However, cf-mRNA composition and its potential clinical applications remain largely unexplored. Here we show, using Next Generation Sequencing-based profiling, that cf-mRNA is enriched in transcripts derived from the bone marrow compared to circulating cells. Further, longitudinal studies involving bone marrow ablation followed by hematopoietic stem cell transplantation in multiple myeloma and acute myeloid leukemia patients indicate that cf-mRNA levels reflect the transcriptional activity of bone marrow-resident hematopoietic lineages during bone marrow reconstitution. Mechanistically, stimulation of specific bone marrow cell populations in vivo using growth factor pharmacotherapy show that cf-mRNA reflects dynamic functional changes over time associated with cellular activity. Our results shed light on the biology of the circulating transcriptome and highlight the potential utility of cf-mRNA to non-invasively monitor bone marrow involved pathologies.

Circulating cell-free mRNA holds great promise as a non-invasive diagnostic biomarker. Here the authors show that cell-free mRNA captures transcripts from the bone marrow and can be used to non-invasively monitor dynamic changes in bone marrow physiology.

Acute Effects of Triathlon Race on Oxidative Stress Biomarkers

The response to strenuous exercise was investigated by reactive oxygen species (ROS) production, oxidative damage, thiol redox status, and inflammation assessments in 32 enrolled triathlon athletes (41.9 ± 7.9 yrs) during Ironman® (IR), or half Ironman® (HIR) competition. In biological samples, inflammatory cytokines, aminothiols (glutathione (GSH), homocysteine (Hcy), cysteine (Cys), and cysteinylglycine (CysGly)), creatinine and neopterin, oxidative stress (OxS) biomarkers (protein carbonyl (PC), thiobarbituric acid-reactive substances (TBARS)), and ROS were assessed. Thirteen HIR and fourteen IR athletes finished the race. Postrace, ROS (HIR +20%; IR +28%; p < 0.0001), TBARS (HIR +57%; IR +101%), PC (HIR +101%; IR +130%) and urinary neopterin (HIR +19%, IR +27%) significantly (range p < 0.05-0.0001) increased. Moreover, HIR showed an increase in total Cys +28%, while IR showed total aminothiols, Cys, Hcy, CysGly, and GSH increase by +48, +30, +58, and +158%, respectively (range p < 0.05-0.0001). ROS production was significantly correlated with TBARS and PC (R 2 = 0.38 and R 2 = 0.40; p < 0.0001) and aminothiols levels (range R 2 = 0.17-0.47; range p < 0.01-0.0001). In particular, ROS was directly correlated with the athletes' age (R 2 = 0.19; p < 0.05), with ultraendurance years of training (R 2 = 0.18; p < 0.05) and the days/week training activity (R 2 = 0.16; p < 0.05). Finally, the days/week training activity (hours/in the last 2 weeks) was found inversely correlated with the IL-6 postrace (R 2 = -0.21; p < 0.01). A strenuous performance, the Ironman® distance triathlon competition, alters the oxidant/antioxidant balance through a great OxS response that is directly correlated to the inflammatory parameters; furthermore, the obtained data suggest that an appropriate training time has to be selected in order to achieve the lowest ROS production and IL-6 concentration at the same time.

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.

The value of cellular components of blood in the setting of trimodal therapy for esophageal cancer

BACKGROUND

Inflammation status plays an important role in the natural history of malignancy. Consequently, hematological markers of systemic inflammation may predict prognosis in neoplasms. This study evaluated the value of cellular blood components changes during neoadjuvant chemoradiotherapy followed by esophagectomy for cancer in predicting prognosis.

METHODS

A cohort of 149 patients was analyzed. Cellular components of blood were assessed before neoadjuvant therapy (A); before surgery (B); and 3 to 5 months after surgery (C); for the following outcomes: pathological response, overall survival (OS), and disease-free survival (DFS). Univariate and multivariate Cox regression models were applied to evaluate the independent prognostic significance of blood count variables.

RESULTS

Low hematocrit (Ht) (C) (HR, 0.85; 95% CI, 0.79-0.92) and high neutrophil-to-lymphocyte ratio (NLR) (C) (HR, 1.07; 95% CI, 1.07-1.10) were related to poor OS. Low Hb (C) (HR, 0.72; 95% CI, 0.58-0.88), red cell distribution width (RDW) (C-A) (HR, 1.16; 95% CI, 1.02-1.31), and NLR (C-A) (1.06; 95% CI, 1.03-1.09) were related to poor DFS. RDW (B-A) (HR, 1.15; 95% CI, 1.08-1.22), RDW (C) (HR, 1.12; 95% CI, 1.04-1.2), NLR (C) (HR, 1.12; 95% CI, 1.08-1.17) were related to systemic recurrence.

CONCLUSION

Variables of routine blood count are easily assessable and their changes throughout trimodal therapy for esophageal carcinoma provide important information for cancer patient's prognosis.

Oxidative stress assessment in breath-hold diving

PURPOSE

Breath-hold diving results in significant changes in blood gases' levels. Challenging variations in oxygen partial pressures may induce reactive oxygen species (ROS) production that exacerbate oxidative stress and, consequently, affect endothelial function. The aim of this study was to investigate the effects of breath-hold diving on oxidative stress damage, assessing ROS production. Nitric oxide metabolites, inducible nitric oxide synthase (iNOS), aminothiols, and renal function were evaluated too as markers of redox status and renal damage.

METHODS

ROS production was assessed with electron paramagnetic resonance. Oxidative status values were measured at pre- and post-40 m dive in a deep swimming pool (Y-40) from six divers (mean age 46.6 ± 9.3 years; height 176 ± 4 cm; BMI 25 ± 2.9 kg/m²).

RESULTS

Significant (p < 0.05) increases at post-dive of ROS production rate (0.158 ± 0.003 vs 0.195 ± 0.006 μmol min^-1), lipid peroxidation (8-isoprostane: 375.67 ± 195.62 vs 420.49 ± 232.31 pg mg^-1 creatinine), nitrate (27.91 ± 19.71 vs 30.80 ± 20.44 μM), iNOS (31.30 ± 4.52 vs 35.68 ± 6.72 IU mL^-1) and neopterin concentration (96.20 ± 40.41 vs 118.76 ± 27.84 μmol mol^-1 creatinine) were recorded. Conversely, the antioxidant capacity significantly decreased (3.423 ± 0.089 vs 3.015 ± 0.284 mM) after immersion.

CONCLUSION

Overproduction of ROS and consequent oxidative damage to lipids of membrane and antioxidant capacity decreasing reflect also a hypoxic condition, which in the breath-hold diving typically occurs in the last few meters below the surface. iNOS produces NO in large quantities under the examined extreme conditions. Neopterin and creatinine concentration level increased, suggesting an "impairment of renal function" as a likely physiological response to PaO₂ variations during dive activity.

Effect of acute exercise on RBC deformability and RBC nitric oxide synthase signalling pathway in young sickle cell anaemia patients

Sickle cell anaemia (SCA) is characterized by reduced red blood cell (RBC) deformability and nitric oxide (NO) bioavailability. The aim of the study was to investigate whether exercise might affect these parameters in SCA. SCA patients and healthy controls (AA) performed an acute submaximal exercise test until subjects reached the first ventilatory threshold (VT 1). Blood was sampled at rest and at VT 1. At rest, free haemoglobin level was higher and RBC count, haemoglobin and haematocrit were lower in SCA compared to AA. RBC deformability was lower in SCA. Exercise had no effect on the tested parameters. RBC NO level was higher in SCA compared to AA at rest and significantly decreased after exercise in SCA. This might be related to a reduction in RBC-NO synthase (RBC-NOS) activation which was only observed in SCA after exercise. Free radical levels were higher in SCA at rest but concentration was not affected by exercise. Marker for lipid peroxidation and antioxidative capacity were similar in SCA and AA and not affected by exercise. In conclusion, a single acute submaximal bout of exercise has no deleterious effects on RBC deformability or oxidative stress markers in SCA, and seems to modulate RBC-NOS signalling pathway.

Effects of a six-week period of congested match play on plasma volume variations, hematological parameters, training workload and physical fitness in elite soccer players

Objectives

The aims of this study were to investigate the effects of a six-week in-season period of soccer training and games (congested period) on plasma volume variations (PV), hematological parameters, and physical fitness in elite players. In addition, we analyzed relationships between training load, hematological parameters and players’ physical fitness.

Methods

Eighteen elite players were evaluated before (T1) and after (T2) a six-week in-season period interspersed with 10 soccer matches. At T1 and T2, players performed the Yo-Yo intermittent recovery test level 1 (YYIR1), the repeated shuttle sprint ability test (RSSA), the countermovement jump test (CMJ), and the squat jump test (SJ). In addition, PV and hematological parameters (erythrocytes [M/mm³], hematocrit [%], hemoglobin [g/dl], mean corpuscular volume [fl], mean corpuscular hemoglobin content [pg], and mean hemoglobin concentration [%]) were assessed. Daily ratings of perceived exertion (RPE) were monitored in order to quantify the internal training load.

Results

From T1 to T2, significant performance declines were found for the YYIR1 (p<0.001, effect size [ES] = 0.5), RSSA (p<0.01, ES = 0.6) and SJ tests (p< 0.046, ES = 0.7). However, no significant changes were found for the CMJ (p = 0.86, ES = 0.1). Post-exercise, RSSA blood lactate (p<0.012, ES = 0.2) and PV (p<0.01, ES = 0.7) increased significantly from T1 to T2. A significant decrease was found from T1 to T2 for the erythrocyte value (p<0.002, ES = 0.5) and the hemoglobin concentration (p<0.018, ES = 0.8). The hematocrit percentage rate was also significantly lower (p<0.001, ES = 0.6) at T2. The mean corpuscular volume, mean corpuscular hemoglobin content and the mean hemoglobin content values were not statistically different from T1 to T2. No significant relationships were detected between training load parameters and percentage changes of hematological parameters. However, a significant relationship was observed between training load and changes in RSSA performance (r = -0.60; p<0.003).

Conclusions

An intensive period of “congested match play” over 6 weeks significantly compromised players’ physical fitness. These changes were not related to hematological parameters, even though significant alterations were detected for selected measures.

Physical fitness is associated with prostaglandin F2α isomers during pregnancy

INTRODUCTION

Pregnancy and physical activity are associated with oxidative stress and immune changes. We hypothesized that pregnant women physically more active in early pregnancy will display a better oxidative stress management and inflammatory response later in pregnancy compared with less active pregnant women.

MATERIAL AND METHODS

Maternal physical activity using accelerometry monitors for 1 week and cardiorespiratory fitness (VO₂ at anaerobic threshold) were assessed at 14-18 weeks in 58 pregnant women. Plasma and erythrocytes membrane samples were obtained from maternal blood samples at 14-18 and 34-37 weeks of pregnancy. Pro-inflammatory prostaglandin (PG) F_2α and oxidative stress-derived F₂-isoprostanes were measured by high-performance liquid chromatography coupled to tandem mass spectrometry.

RESULTS

Higher physical activity levels at 14-18 weeks measured by mean counts per minute, >30 min/d of moderate to vigorous activity or >6500 steps/d at 14-18 weeks of pregnancy were associated with lower levels of total plasmatic PGF_2α later in pregnancy. Concentrations of 5 F₂-isomers in erythrocyte membranes in late pregnancy were significantly higher in the third (17.5-19.5 mL kg^-1 min^-1) and/or fourth (19.6-27.7 mL kg^-1 min^-1) quartiles of cardio-respiratory fitness compared to the first quartile (13.9-15.9 mL kg^-1 min^-1).

CONCLUSIONS

Overall, higher cardio-respiratory fitness in early pregnancy is associated with enhanced erythrocyte membranes oxidation at 34-37 weeks reflecting a higher oxygen transfer capacity. Also, the most active women experienced lower circulating levels of pro-inflammatory PGF_2α in plasma at 34-37 weeks, a marker associated with adverse antenatal inflammation-associated conditions. These results support the practice of physical activity by pregnant women.

Squeezing for Life - Properties of Red Blood Cell Deformability

Deformability is an essential feature of blood cells (RBCs) that enables them to travel through even the smallest capillaries of the human body. Deformability is a function of (i) structural elements of cytoskeletal proteins, (ii) processes controlling intracellular ion and water handling and (iii) membrane surface-to-volume ratio. All these factors may be altered in various forms of hereditary hemolytic anemia, such as sickle cell disease, thalassemia, hereditary spherocytosis and hereditary xerocytosis. Although mutations are known as the primary causes of these congenital anemias, little is known about the resulting secondary processes that affect RBC deformability (such as secondary changes in RBC hydration, membrane protein phosphorylation, and RBC vesiculation). These secondary processes could, however, play an important role in the premature removal of the aberrant RBCs by the spleen. Altered RBC deformability could contribute to disease pathophysiology in various disorders of the RBC. Here we review the current knowledge on RBC deformability in different forms of hereditary hemolytic anemia and describe secondary mechanisms involved in RBC deformability.

Does Iron Supplementation Improve Performance in Iron-Deficient Nonanemic Athletes?

CONTEXT

Supplementing iron-deficient nonanemic (IDNA) athletes with iron to improve performance is a trend in endurance sports.

OBJECTIVES

To investigate the benefits of iron on performance, identify a ferritin level cutoff in IDNA athletes, and determine which iron supplementation regimens are most effective.

DATA SOURCES

A search of the PubMed, CINAHL, Embase, ERIC, and Cochrane databases was performed in 2014 including all articles. Citations of pertinent review articles were also searched. In 2017, the search was repeated.

STUDY SELECTION

Inclusion criteria comprised studies of level 1 to 3 evidence, written in the English language, that researched iron supplementation in nonanemic athletes and reported performance outcomes.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 3.

DATA EXTRACTION

The search terms used included athletic performance, resistance training, athletes, physical endurance, iron, iron deficiency, supplement, non-anemic, low ferritin, ferritin, ferritin blood level, athletes, and sports.

RESULTS

A total of 1884 studies were identified through the initial database search, and 13 were identified through searching references of relevant review articles. A subsequent database search identified 46 studies. Following exclusions, 12 studies with a total of 283 participants were included. Supplementing IDNA athletes with iron improved performance in 6 studies (146 participants) and did not improve performance in the other 6 studies (137 participants). In the 6 studies that showed improved performance with iron supplementation, all used a ferritin level cutoff of ≤20 μg/L for treatment. Additionally, all studies that showed improved performance used oral iron as a supplement.

CONCLUSION

The evidence is equivocal as to whether iron supplementation in IDNA athletes improves athletic performance. Supplementing athletes with ferritin levels <20 μg/L may be more beneficial than supplementing athletes with higher baseline ferritin levels.

Erythrocyte microRNA sequencing reveals differential expression in relapsing-remitting multiple sclerosis

Background

There is a paucity of knowledge concerning erythrocytes in the aetiology of Multiple Sclerosis (MS) despite their potential to contribute to disease through impaired antioxidant capacity and altered haemorheological features. Several studies have identified an abundance of erythrocyte miRNAs and variable profiles associated with disease states, such as sickle cell disease and malaria. The aim of this study was to compare the erythrocyte miRNA profile of relapsing-remitting MS (RRMS) patients to healthy sex- and age-matched controls.

Methods

Erythrocytes were purified by density-gradient centrifugation and RNA was extracted. Following library preparation, samples were run on a HiSeq4000 Illumina instrument (paired-end 100 bp sequencing). Sequenced erythrocyte miRNA profiles (9 patients and 9 controls) were analysed by DESeq2. Differentially expressed miRNAs were validated by RT-qPCR using miR-152-3p as an endogenous control and replicated in a larger cohort (20 patients and 18 controls). After logarithmic transformation, differential expression was determined by two-tailed unpaired t-tests. Logistic regression analysis was carried out and receiver operating characteristic (ROC) curves were generated to determine biomarker potential.

Results

A total of 236 erythrocyte miRNAs were identified. Of twelve differentially expressed miRNAs in RRMS two showed increased expression (adj. p < 0.05). Only modest fold-changes were evident across differentially expressed miRNAs. RT-qPCR confirmed differential expression of miR-30b-5p (0.61 fold, p < 0.05) and miR-3200-3p (0.36 fold, p < 0.01) in RRMS compared to healthy controls. Relative expression of miR-3200-5p (0.66 fold, NS p = 0.096) also approached significance. MiR-3200-5p was positively correlated with cognition measured by audio-recorded cognitive screen (r = 0.60; p < 0.01). MiR-3200-3p showed greatest biomarker potential as a single miRNA (accuracy = 75.5%, p < 0.01, sensitivity = 72.7%, specificity = 84.0%). Combining miR-3200-3p, miR-3200-5p, and miR-30b-5p into a composite biomarker increased accuracy to 83.0% (p < 0.05), sensitivity to 77.3%, and specificity to 88.0%.

Conclusions

This is the first study to report differences in erythrocyte miRNAs in RRMS. While the role of miRNAs in erythrocytes remains to be elucidated, differential expression of erythrocyte miRNAs may be exploited as biomarkers and their potential contribution to MS pathology and cognition should be further investigated.

Electronic supplementary material

The online version of this article (10.1186/s12920-018-0365-7) contains supplementary material, which is available to authorized users.

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

BACKGROUND

Acute exercise increases red blood cell-nitric oxide synthase (RBC-NOS) activation and RBC deformability but the effect of regular training remains unclear.

OBJECTIVE

To detect the chronic effect of enduring moderate and high intensity training on the RBC-NOS/NO pathway and to detect a relation between RBC deformability and endurance capacity.

METHODS

38 healthy male subjects were randomly assigned to one of three training groups: High Volume Training (HVT; 120-140 beats per minute (bpm)), High Intensity Training (HIT; 160-180 bpm) and Moderate Intensity Training (MIT; 140-160 bpm). Blood parameters, maximum oxygen capacity (VO2 max), RBC deformability, RBC nitrite level and RBC-NOS activation were measured after venous blood sampling at rest pre (T0) and after six weeks of training (T1).

RESULTS

RBC-NOS activation, RBC nitrite concentration and RBC deformability were significantly increased at T1 in the HIT group. Parameters were unaltered in MIT and HVT. Maximum oxygen uptake was only significantly increased in the HIT group and regression analysis revealed positive regression between VO2 max and RBC deformability.

CONCLUSIONS

High intensity training was the only training programme that sustainably affected RBC-NOS dependent NO production and performance capacity. HIT therefore represents a time efficient training program resulting in improved RBC function potentially improving physical condition.

Training-induced annual changes in red blood cell profile in highly-trained endurance and speed-power athletes

BACKGROUND

An extensive body of literature exists on the effects of training on hematological parameters, but the previous studies have not reported how hematological parameters respond to changes in training loads within consecutive phases of the training cycle in highly-trained athletes in extremely different sport disciplines. The aim of this study was to identify changes in red blood cell (RBC) profile in response to training loads in consecutive phases of the annual training cycle in highly-trained sprinters (8 men, aged 24±3 years) and triathletes (6 men, aged 24±4 years) who competed at the national and international level.

METHODS

Maximal oxygen uptake (VO2max), RBC, hemoglobin (Hb), hematocrit (Ht), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) and RBC distribution width (RDW) were determined in four characteristic training phases (transition, general subphase of the preparation phase, specific subphase of the preparation phase and competition phase).

RESULTS

Our main findings are that: 1) Hb, MCH and MCHC in triathletes and MCV in both triathletes and sprinters changed significantly over the annual training cycle; 2) triathletes had significantly higher values than sprinters only in case of MCH and MCHC after the transition and general preparation phases but not after the competition phase when MCH and MCHC were higher in sprinters; and 3) in triathletes, Hb, MCH and MCHC substantially decreased after the competition phase, which was not observed in sprinters. The athletes maintained normal ranges of all hematological parameters in four characteristic training phases.

CONCLUSIONS

Although highly-trained sprinters and triathletes do not significantly differ in their levels of most hematological parameters, these groups are characterized by different patterns of changes during the annual training cycle. Our results suggest that when interpreting the values of hematological parameters in speed-power and endurance athletes, a specific phase of the annual training cycle should be taken into account.

Dietary thiols in exercise: oxidative stress defence, exercise performance, and adaptation

Endurance athletes are susceptible to cellular damage initiated by excessive levels of aerobic exercise-produced reactive oxygen species (ROS). Whilst ROS can contribute to the onset of fatigue, there is increasing evidence that they play a crucial role in exercise adaptations. The use of antioxidant supplements such as vitamin C and E in athletes is common; however, their ability to enhance performance and facilitate recovery is controversial, with many studies suggesting a blunting of training adaptations with supplementation. The up-regulation of endogenous antioxidant systems brought about by exercise training allows for greater tolerance to subsequent ROS, thus, athletes may benefit from increasing these systems through dietary thiol donors. Recent work has shown supplementation with a cysteine donor (N-acetylcysteine; NAC) improves antioxidant capacity by augmenting glutathione levels and reducing markers of oxidative stress, as well as ergogenic potential through association with delayed fatigue in numerous experimental models. However, the use of this, and other thiol donors may have adverse physiological effects. A recent discovery for the use of a thiol donor food source, keratin, to potentially enhance endogenous antioxidants may have important implications for endurance athletes hoping to enhance performance and recovery without blunting training adaptations.

Comparison of human erythrocyte purine nucleotide metabolism and blood purine and pyrimidine degradation product concentrations before and after acute exercise in trained and sedentary subjects

This study aimed at evaluating the concentration of erythrocyte purine nucleotides (ATP, ADP, AMP, IMP) in trained and sedentary subjects before and after maximal physical exercise together with measuring the activity of purine metabolism enzymes as well as the concentration of purine (hypoxanthine, xanthine, uric acid) and pyrimidine (uridine) degradation products in blood. The study included 15 male elite rowers [mean age 24.3 ± 2.56 years; maximal oxygen uptake (VO_2max) 52.8 ± 4.54 mL/kg/min; endurance and strength training 8.2 ± 0.33 h per week for 6.4 ± 2.52 years] and 15 sedentary control subjects (mean age 23.1 ± 3.41 years; VO_2max 43.2 ± 5.20 mL/kg/min). Progressive incremental exercise testing until refusal to continue exercising was conducted on a bicycle ergometer. The concentrations of ATP, ADP, AMP, IMP and the activities of adenine phosphoribosyltransferase (APRT), hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and phosphoribosyl pyrophosphate synthetase (PRPP-S) were determined in erythrocytes. The concentrations of hypoxanthine, xanthine, uric acid and uridine were determined in the whole blood before exercise, after exercise, and 30 min after exercise testing. The study demonstrated a significantly higher concentration of ATP in the erythrocytes of trained subjects which, in part, may be explained by higher metabolic activity on the purine re-synthesis pathway (significantly higher PRPP-S, APRT and HGPRT activities). The ATP concentration, just as the ATP/ADP ratio, as well as an exercise-induced increase in this ratio, correlates with the VO_2max level in these subjects which allows them to be considered as the important factors characterising physical capacity and exercise tolerance. Maximal physical exercise in the group of trained subjects results not only in a lower post-exercise increase in the concentration of hypoxanthine, xanthine and uric acid but also in that of uridine. This indicates the possibility of performing high-intensity work with a lower loss of not only purine but also pyrimidine.

α-Synuclein Aggregates with β-Amyloid or Tau in Human Red Blood Cells: Correlation with Antioxidant Capability and Physical Exercise in Human Healthy Subjects

Neurodegenerative disorders (NDs) are characterized by abnormal accumulation/misfolding of specific proteins, primarily α-synuclein (α-syn), β-amyloid_1-42 (Aβ), and tau, in both brain and peripheral tissue. In addition to homo-oligomers, the role of α-syn interactions with Aβ or tau has gradually emerged. The altered protein accumulation has been related to both oxidative stress and physical activity; nevertheless, no correlation among the presence of peripheral α-syn hetero-aggregates, antioxidant capacity, and physical exercise has been discovered as of yet. Herein, the content of α-syn, Aβ, tau, and of their heterocomplexes was determined in red blood cells (RBCs) of healthy subjects (sedentary and athletes). Such parameters were related to the extent of the antioxidant capability (AOC), a key marker of oxidative stress in aging-related pathologies, and to physical exercise, which is known to play an important preventive role in NDs and to modulate oxidative stress. Tau content and plasma AOC toward hydroxyl radicals were both reduced in older or sedentary subjects; in contrast, α-syn and Aβ accumulated in elderly subjects and showed an inverse correlation with both hydroxyl AOC and the level of physical activity. For the first time, α-syn heterocomplexes with Aβ or tau were quantified and demonstrated to be inversely related to hydroxyl AOC. Furthermore, α-syn/Aβ aggregates were significantly reduced in athletes and inversely correlated with physical activity level, independent of age. The positive correlation between antioxidant capability/physical activity and reduced protein accumulation was confirmed by these data and suggested that peripheral α-syn heterocomplexes may represent new indicators of ND-related protein misfolding.

Endurance training alters enzymatic and rheological properties of red blood cells (RBC) in type 2 diabetic men during in vivo RBC aging

This study examines the effects of endurance training on red blood cells (RBC) in seventeen non-insulin-dependent type 2 diabetic men with a special focus on in vivo RBC aging. Venous blood was collected pre- and post-training at rest. RBC from whole blood and RBC separated according to cell age by density-gradient centrifugation were analyzed. RBC deformability was measured by ektacytometry. Immunohistochemical staining was performed to quantify the RBC-nitric oxide (NO) synthase activation (RBC-NOSSer1177) because RBC-NOS-produced NO can contribute to increased RBC deformability. The proportion of "young" RBC was significantly higher post-training. RBC deformability of all RBC (RBC of all ages) remained unaltered post-training. During RBC aging, RBC deformability decreased in both pre- and post-training. However, the training significantly increased RBC deformability in "young" and reduced their deformability in aging RBC. RBC-NOS activation remained unaltered in all RBC post-training. It tendentially increased in aging RBC pre-training, but did not change during aging post-training. The training significantly reduced RBC-NOS activation in "old" RBC. Endurance training may improve the RBC system (higher amount of "young" RBC which are more deformable). It remains speculative whether changes in older RBC (reduced RBC-NOS activation and deformability) could lead to more rapid elimination of aged RBC.

Effects of acute and chronic exercise on the osmotic stability of erythrocyte membrane of competitive swimmers

This study aimed to evaluate the influence of acute and chronic exercise on erythrocyte membrane stability and various blood indices in a population consisting of five national-level male swimmers, over 18 weeks of training. The evaluations were made at the beginning and end of the 1st, 7th, 13th and 18th weeks, when volume and training intensity have changed. The effects manifested at the beginning of those weeks were considered due to chronic adaptations, while the effects observed at the end of the weeks were considered due to acute manifestations of the exercise load of that week. Acute changes resulting from the exercise comprised increases in creatine kinase activity (CK) and leukocyte count (Leu), and decrease in hematocrit (Ht) and mean corpuscular volume (MCV), at the end of the first week; increase in the activities of CK and lactate dehydrogenase (LDH), in the uric acid (UA) concentration and Leu count, at the end of the seventh week; increases in CK and LDH activities and in the mean corpuscular hemoglobin concentration (MCHC), at the end of the 13th week; and decrease in the value of the osmotic stability index 1/H₅₀ and increases in the CK activity and platelets (Plt) count, at the end of the 18th week. Chronic changes due to training comprised increase in the values of 1/H₅₀, CK, LDH, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), serum iron (Fe), MCV and Plt. Although acute training has resulted in decrease in the osmotic stability of erythrocytes, possibly associated with exacerbation of the oxidative processes during intense exercise, chronic training over 18 weeks resulted in increased osmotic stability of erythrocytes, possibly by modulation in the membrane cholesterol content by low and high density lipoproteins.

Exercise-induced ROS in heat shock proteins response

Cells have evolved multiple and sophisticated stress response mechanisms aiming to prevent macromolecular (including proteins, lipids, and nucleic acids) damage and to maintain or re-establish cellular homeostasis. Heat shock proteins (HSPs) are among the most highly conserved, ubiquitous, and abundant proteins in all organisms. Originally discovered more than 50 years ago through heat shock stress, they display multiple, remarkable roles inside and outside cells under a variety of stresses, including also oxidative stress and radiation, recognizing unfolded or misfolded proteins and facilitating their restructuring. Exercise consists in a combination of physiological stresses, such as metabolic disturbances, changes in circulating levels of hormones, increased temperature, induction of mild to severe inflammatory state, increased production of reactive oxygen and nitrogen species (ROS and RNS). As a consequence, exercise is one of the main stimuli associated with a robust increase in different HSPs in several tissues, which appears to be also fundamental in facilitating the cellular remodeling processes related to the training regime. Among all factors involved in the exercise-related modulation of HSPs level, the ROS production in the contracting muscle or in other tissues represents one of the most attracting, but still under discussion, mechanism. Following exhaustive or damaging muscle exercise, major oxidative damage to proteins and lipids is likely involved in HSP expression, together with mechanically induced damage to muscle proteins and the inflammatory response occurring several days into the recovery period. Instead, the transient and reversible oxidation of proteins by physiological concentrations of ROS seems to be involved in the activation of stress response following non-damaging muscle exercise. This review aims to provide a critical update on the role of HSPs response in exercise-induced adaptation or damage in humans, focusing on experimental results where the link between redox homeostasis and HSPs expression by exercise has been addressed. Further, with the support of in vivo and in vitro studies, we discuss the putative molecular mechanisms underlying the ROS-mediated modulation of HSP expression and/or activity during exercise.

Oxidative Stress Assessment in Response to Ultraendurance Exercise: Thiols Redox Status and ROS Production according to Duration of a Competitive Race

Purpose. Response to an ultraendurance competitive race on thiols redox status, reactive oxygen species (ROS) production, and oxidative stress (OxS) was investigated according to duration. Methods. Twenty-four elite runners were examined: six completed 50 km and eighteen 100 km. Blood and urine samples were collected before and immediately after the race. Erythrocytes and plasma aminothiols by high-performance liquid chromatography, total antioxidant capacity (TAC), and OxS biomarkers (protein carbonyl (PC), thiobarbituric acid-reactive substances (TBARS), 8-isoprostane (8-iso-PGF2α), and 8-OH-2-deoxyguanosine (8-OH-dG)) by immunoenzymatic assays and ROS production by Electron Paramagnetic Resonance were assessed. Results. Significant increases (P between <0.05 and <0.0001) were recorded in plasma total and oxidized aminothiols concentration and TAC (P < 0.0001) only after 100 km: plasmatic (ROS production (+12 versus +29%), PC (+54 versus +115%), and TBARS (+28 versus +55%)) and urinary (8-OH-dG.creatinine⁻¹ (+71 versus +158%) and 8-iso-PGF2α.creatinine⁻¹ (+43 versus +135%)) concentrations for 50 and 100 km (duration 4 h 3′ versus 8 h 42′), respectively. Conclusion. Very prolonged ultraendurance exercise causes an increase in ROS production and OxS depending on specific biomarker examined but always linearly and directly related to exercise duration. Redox status of erythrocytes was preserved. A relationship between running performance and both prerace ROS production and antioxidant-redox status was found in 100 km race.