Decreased Blood Glucose and Lactate: Is a Useful Indicator of Recovery Ability in Athletes?

Gut microbiota are differentially correlated with blood pressure status in African American collegiate athletes: A pilot study

Hypertension (HTN) is common among athletes and the most recent epidemiologic data reports that cardiovascular (CV) sudden death is significantly greater in African Americans (AAs). Gut microbial dysbiosis (a poorly diverse stool microbial profile) has been associated with HTN in sedentary people but microbial characteristics of athletes with HTN are unknown. Our purpose was to differentiate microbiome characteristics associated with BP status in AA collegiate athletes. Thirty AA collegiate athletes were stratified by normal BP (systolic BP (SBP) ≤130 mmHg; n = 15) and HTN (SBP ≥130 mmHg; n = 15). 16S rRNA gene sequencing was performed on stool samples to identify microbes at the genus level. We did not observe any significant differences in alpha diversity, but beta diversity was different between groups. Principal coordinate analysis was significantly different (PERMANOVA, p < 0.05, R = 0.235) between groups. Spearman rank correlations showed a significant (p < 0.05) correlation between systolic BP and abundances for Adlercreutzia (R = 0.64), Coprococcus (R = 0.49), Granulicatella (R = 0.63), and Veillonella (R = 0.41). Gut microbial characteristics were associated with differentially abundant microbial genus' and BP status. These results will direct future studies to define the functions of these microbes associated with BP in athletes.

Association between Oxidative Stress with Psychological and Biochemical Variables in a Sample of Healthy Mexican People: A Cross-Sectional Study

Oxidative stress (OS) has been linked to cell damage and chronic disease development; however, the study of psychological factors related with OS has been limited, as has its relationship with biochemical and personal variables. Therefore, the aim of this study was to evaluate the association between a wide variety of personal, psychological, and biochemical factors with OS in a sample of healthy Mexican people. A total of 134 participants, from which 70 (52%) were women, without known chronic conditions were included in the study, and the molecule 8-hydroxy-2'-deoxyguanosine (8-OHdG) was also measured as a marker of OS. We observed in the multivariate analysis of the whole sample that depressive symptoms (measured with CES-D scale) were the only psychological variable significantly associated (positively) with 8-OHdG. In addition, the following sociodemographic variables were associated with 8-OHdG: age, schooling (positively correlated), and the frequency of vitamins/antioxidant consumption (negatively correlated). The biochemical variables of erythrocytes in urine and amylase were positively correlated with 8-OHdG, while glucose was negatively correlated with it. Additional biochemical variables were associated in the multivariate analysis of each sex, including the positive correlation of LDL-cholesterol, LDH enzyme, lymphocytes, and the negative correlation of phosphorus and eosinophils in women's samples, as well as the positive correlation of potassium, uric acid, and leucocytes in urine and the negative correlation of erythrocytes and lipase in the men's samples. In conclusion, depression was the only psychological variable positively correlated with 8-OHdG after adjusting for confounders, and new associations with biochemical variables were found with some differences between sexes.

Advancing athletic assessment by integrating conventional methods with cutting-edge biomedical technologies for comprehensive performance, wellness, and longevity insights

In modern athlete assessment, the integration of conventional biochemical and ergophysiologic monitoring with innovative methods like telomere analysis, genotyping/phenotypic profiling, and metabolomics has the potential to offer a comprehensive understanding of athletes' performance and potential longevity. Telomeres provide insights into cellular functioning, aging, and adaptation and elucidate the effects of training on cellular health. Genotype/phenotype analysis explores genetic variations associated with athletic performance, injury predisposition, and recovery needs, enabling personalization of training plans and interventions. Metabolomics especially focusing on low-molecular weight metabolites, reveal metabolic pathways and responses to exercise. Biochemical tests assess key biomarkers related to energy metabolism, inflammation, and recovery. Essential elements depict the micronutrient status of the individual, which is critical for optimal performance. Echocardiography provides detailed monitoring of cardiac structure and function, while burnout testing evaluates psychological stress, fatigue, and readiness for optimal performance. By integrating this scientific testing battery, a multidimensional understanding of athlete health status can be achieved, leading to personalized interventions in training, nutrition, supplementation, injury prevention, and mental wellness support. This scientifically rigorous approach hereby presented holds significant potential for improving athletic performance and longevity through evidence-based, individualized interventions, contributing to advances in the field of sports performance optimization.

DIEP flap perfusion assessment using microdialysis versus Doppler ultrasonography: A comparative study

BACKGROUND

The increasing number of buried free-tissue transfer procedures and the need for an objective method to evaluate vascular complications of free flaps has led to the development of new technologies. Microdialysis has been used to monitor free flaps using interstitial biological markers. Previous uses mainly focused on muscular flaps. Our aim is to compare external Doppler ultrasonography (EDU) evaluation versus microdialysis in the early follow-up of adipocutaneous flaps, and propose an efficient postoperative monitoring protocol.

METHODS

We retrospectively assessed 68 consecutive DIEP flaps (50 patients) performed between January 2019 and March 2021. All flaps received standardized post-operative monitoring using clinical signs, EDU and microdialysis. Glucose and lactate concentrations were assessed using glucose <1 mmol/L and lactate >6 mmol/L as ischemic trend thresholds. We calculated Glucose/Lactate ratio as a new parameter for the assessment of flap viability.

RESULTS

Among all the 68 flaps, two flaps returned to the operative theater when a combination of unsatisfactory microdialysis values and clinical/EDU signs identified vascular impairment; only one developed total flap necrosis. Reoperation rate was 2.94% with an overall flap success rate of 98.53%. External Doppler ultrasonography had 100% sensitivity and 82% specificity, while microdialysis had 100% sensitivity and 100% specificity.

CONCLUSIONS

Microdialysis values proved flap viability sooner than external Doppler ultrasonography, making it an excellent tool for post-operative monitoring. With the appropriate thresholds for glucose and lactate concentrations, and glucose/lactate ratio used as a new parameter, it can help potentially avoiding unnecessary re-explorations, and reducing flap ischemia times.

Lactate thresholds and role of nitric oxide in male rats performing a test with forced swimming to exhaustion

The present study assessed a complex of biochemical parameters at the anaerobic threshold (AT) in untrained male Wistar rats with different times to exhaustion (Tex ) from swimming. The first group of rats was randomly divided into six subgroups and subjected to a swimming test to exhaustion without a load or with a load of 2%-10% of body weight (BW). In the first group, we established that for untrained rats, the load of 4% BW in the swimming to exhaustion test was optimal for endurance assessment in comparison with other loads. The second group of rats went through a preliminary test with swimming to exhaustion at 4% BW and was then divided into two subgroups: long swimming time (LST, Tex  > 240 min) and short swimming time (SST, Tex  < 90 min). All rats of the second group performed, for 6 days, an experimental training protocol: swimming for 20 min each day with weight increasing each day. We established that the AT was 3% BW in SST rats and 5% BW in LST rats. The AT shifted to the right on the lactate curve in LST rats. Also, at the AT in the LST rats, we found significantly lower levels of blood lactate, cortisol, and NO.

A modified formula using energy system contributions to calculate pure maximal rate of lactate accumulation during a maximal sprint cycling test

Purpose: This study aimed at comparing previous calculating formulas of maximal lactate accumulation rate ( ν La.max) and a modified formula of pure ν La.max (P ν La.max) during a 15-s all-out sprint cycling test (ASCT) to analyze their relationships. Methods: Thirty male national-level track cyclists participated in this study (n = 30) and performed a 15-s ASCT. The anaerobic power output (Wpeak and Wmean), oxygen uptake, and blood lactate concentrations (La-) were measured. These parameters were used for different calculations of ν La.max and three energy contributions (phosphagen, W PCr; glycolytic, W Gly; and oxidative, W Oxi). The P ν La.max calculation considered delta La-, time until Wpeak (tPCr-peak), and the time contributed by the oxidative system (tOxi). Other ν La.max levels without tOxi were calculated using decreasing time by 3.5% from Wpeak (tPCr -3.5%) and tPCr-peak. Results: The absolute and relative W PCr were higher than W Gly and W Oxi (p < 0.0001, respectively), and the absolute and relative W Gly were significantly higher than W Oxi (p < 0.0001, respectively); ν La.max (tPCr -3.5%) was significantly higher than P ν La.max and ν La.max (tPCr-peak), while ν La.max (tPCr-peak) was lower than P ν La.max (p < 0.0001, respectively). P ν La.max and ν La.max (tPCr-peak) were highly correlated (r = 0.99; R 2 = 0.98). This correlation was higher than the relationship between P ν La.max and ν La.max (tPCr -3.5%) (r = 0.87; R 2 = 0.77). ν La.max (tPCr-peak), P ν La.max, and ν La.max (tPCr -3.5%) were found to correlate with absolute Wmean and W Gly. Conclusion: P ν La.max as a modified calculation of ν La.max provides more detailed insights into the inter-individual differences in energy and glycolytic metabolism than ν La.max (tPCr-peak) and ν La.max (tPCr -3.5%). Because W Oxi and W PCr can differ remarkably between athletes, implementing their values in P ν La.max can establish more optimized individual profiling for elite track cyclists.

Effects of Low- and High-Frequency Cardiac Rehabilitation on Risk Factors, Physical Fitness and Quality of Life in Middle-Aged Women with Coronary Heart Disease

Cardiac rehabilitation (CR) is a system that comprehensively manages risk factors to reduce the recurrence rate after cardiovascular disease treatment. This study compared the effects of home-based low-frequency CR (1-2 times/week) and center-based high-frequency CR (3-5 times/week) for 12 weeks. This study was conducted as an observational case-control study. Ninety women, ages 45 to 60, who underwent coronary artery stenting were enrolled. Measurement variables were waist circumference, body mass index (BMI), blood pressure (BP), total cholesterol (TC), low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC), triglycerides (TG), glucose, VO₂ peak, body composition, and quality of life. Significant changes were observed in systolic BP, TC, LDLC, TG, VO₂ peak, exercise duration, and quality of life in both groups. However, BMI, waist circumference, body fat percentage, HDLC, and blood glucose only exhibited significant changes with HFT. The interaction effects according to time and group were as follows: systolic BP, waist circumference, body fat, BMI, HDLC, and glucose (p < 0.05). Therefore, in CR participants, HFT improved more than LFT on obesity factors, HDLC, and glucose change. As well as center-based HFT, home-based LFT also improved risk factors for cardiovascular disease, fitness, and quality of life. For female patients who have difficulty visiting the CR center frequently, home-based LFT may be a CR program that can be presented as an alternative.

Physiological significance of elevated levels of lactate by exercise training in the brain and body

For the past 200 years, lactate has been regarded as a metabolic waste end product that causes fatigue during exercise. However, lactate production is closely correlated with energy metabolism. The lactate dehydrogenase-catalyzed reaction uses protons to produce lactate, which delays ongoing metabolic acidosis. Of note, lactate production differs depending on exercise intensity and is not limited to muscles. Importantly, controlling physiological effect of lactate may be a solution to alleviating some chronic diseases. Released through exercise, lactate is an important biomarker for fat oxidation in skeletal muscles. During recovery after sustained strenuous exercise, most of the lactate accumulated during exercise is removed by direct oxidation. However, as the muscle respiration rate decreases, lactate becomes a desirable substrate for hepatic glucose synthesis. Furthermore, improvement in brain function by lactate, particularly, through the expression of vascular endothelial growth factor and brain-derived neurotrophic factor, is being increasingly studied. In addition, it is possible to improve stress-related symptoms, such as depression, by regulating the function of hippocampal mitochondria, and with an increasingly aging society, lactate is being investigated as a preventive agent for brain diseases such as Alzheimer's disease. Therefore, the perception that lactate is equivalent to fatigue should no longer exist. This review focuses on the new perception of lactate and how lactate acts extensively in the skeletal muscles, heart, brain, kidney, and liver. Additionally, lactate is now used to confirm exercise performance and should be further studied to assess its impact on exercise training.

Local biocompatibility and biochemical profile of hepatic cytolysis in subcutaneous implantation of polylactide matrices

The aim of the study was to investigate local biocompatibility and systemic effects of nonwoven polylactide (PLA) matrices on blood and liver parameters after their subcutaneous implantation in Wistar rats.

Materials and methods. Bioabsorbable fibrous PLA matrices were produced by electrospinning and had dimensions (10 × 10 mm², thickness of no more than 0.5 mm; fiber diameter in the matrix ~1 μm) appropriate for subcutaneous implantation in white laboratory rats. Polymer implants were sterilized in ethylene oxide vapor. Thirty days after the implantation of PLA matrices, local biocompatibility according to GOST ISO 10993-6-2011, cellular parameters (total leukocyte count, hemogram, erythrocyte count, hemoglobin concentration), and biochemical blood parameters (lactate concentration, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels) were studied, and a standard histologic evaluation of the liver was performed.

Results. PLA matrix samples were mild local irritants on a scale of 1–1.9 points according to GOST ISO 10993-6-2011 criteria 30 days after the subcutaneous implantation. The median density of distribution of multinucleated giant cells (MNGCs) in the connective tissue around and in PLA matrices was 1,500 (1,350; 1,550) per 1 mm² of a slice. Pronounced leukocytic reaction due to lymphocytosis was noted (an increase by 1.7 times compared with a sham-operated (SO) control group, р < 0.02). The absence of a significant neutrophil count in the blood revealed sterile inflammation proceeding in the subcutaneous tissue around the PLA materials. Normalization of hepatic cytolysis markers (ALT and AST activity) in the blood without pronounced changes in the structure of the liver and the number of binuclear hepatocytes was noted. These markers were increased in SO controls (ALT up to 123% and AST up to 142%, p < 0.001 compared with values in the intact group).

Conclusion. Nonwoven PLA matrices are biocompatible with subcutaneous tissue, undergo bioresorption by MNGCs, and have a distant protective effect on the functional state of the liver in laboratory animals. Hypotheses on the detected systemic effect during subcutaneous implantation of PLA matrices were discussed; however, specific mechanisms require further study.

Effects of individualized low-intensity mat Pilates on aerobic capacity and recovery ability in adults

PURPOSE

Although Pilates is one of the most widely performed physical activities in Korea, no physiological evidence is available regarding its energy recovery ability. Therefore, the purpose of this study was to investigate the effects of individualized low-intensity mat Pilates on aerobic capacity and recovery ability in adults.

METHODS

Ten physically active women participated in this study. Pre- and post-lactate threshold (LT) tests were performed to compare jogging/running speeds (S; km·h-1) and heart rates (HR; beats·min-1) at 1.5, 2.0, 3.0, 4.0 mmol·L-1 lactate concentrations (La-). Subjects performed 1 h of low-intensity mat Pilates twice a week for four weeks. During these sessions, exercise intensity was determined based on the heart rate corresponding to individualized low-inten- sity recovery zone 1, which was estimated using a mathematical model of log-log LT1 (from pre-test; &lt; 2 mmol·L-1). All physiological variables were measured before and after exercise intervention.

RESULTS

Significant differences were found in body mass increase and body mass index increase between the pre- and post-tests (p = 0.016 and p = 0.014, respectively, effect size (ES) = 0.13; ES = -0.11). Levels of La- between 1.0 and 1.4 m·s-1 in the post-LT test tended to decrease, although such decrease was not significantly different. Moderate to high positive correlations between differences (Δ) of S and ΔHR at 1.5, 3.0, and 4.0 mmol·L-1La- were observed.

CONCLUSION

Positive correlations between ΔS and ΔHR at certain La- levels indicate that low-intensity mat Pilates based on heart rate corresponding to individualized recovery zone 1 might be recommended for physically active adults.

Energetic Contributions Including Gender Differences and Metabolic Flexibility in the General Population and Athletes

Metabolic flexibility includes the ability to perform fat and carbohydrate oxidation, as well as oxidative capacity, which is associated with mitochondrial function, energetic contributions, and physical health and performance. During a session of graded incremental exercise testing (GIET), we investigated metabolic flexibility, the contributions of three energy systems, and performances of individuals with different metabolic characteristics. Fifteen general population (GP; n = 15, male n = 7, female n = 8) and 15 national-level half-marathon and triathlon athletes (A; n = 15, male n = 7, female n = 8) participated in this study. During GIET, heart rate (HR), oxygen uptake (V˙O_2mean and V˙CO_2mean), metabolic equivalents (METs) in V˙O_2mean, and blood glucose and lactate concentrations (La⁻) were measured. Furthermore, jogging/running speeds (S) at specific La⁻, fat and carbohydrate oxidations (FATox and CHOox), and energetic contributions (oxidative; W_Oxi, glycolytic; W_Gly, and phosphagen; W_PCr) were calculated. The percentages of HR_max, relative V˙O_2mean, V˙CO_2mean, and METs in V˙O_2mean were all lower in A than they were in GP. FATox values were lower in GP than in A, while CHOox and La⁻ were higher in GP than in A. Negative correlations between La⁻ and FATox were also observed in both groups. Contributions of W_Oxi, W_Gly, and W_PCr were higher in GP than in A during GIET. Moreover, values of W_Gly, and W_PCr were significantly lower and higher, respectively, in male GP than in female GP. Furthermore, S at specific La⁻ were higher in A than in GP. It is suggested that an individualized low-intensity recovery exercise program be established, to achieve increased metabolic flexibility and oxidative capacity (aerobic base), such as public health improvements and a greater volume of higher exercise intensities; this is the type of exercise that elite athletes worldwide mostly perform during their training period and progression. This may prevent cardiac/metabolic diseases in GP.

A Novel Formula Comprising Wolfberry, Figs, White Lentils, Raspberries, and Maca (WFWRM) Induced Antifatigue Effects in a Forced Exercise Mouse Model

Long-term body fatigue poses a threat to human health. To explore novel sources of antifatigue medicine and food, we developed a novel formula composed of wolfberry, figs, white lentils, raspberries, and maca (WFWRM) according to the theory of traditional Chinese medicine. In this study, we explored whether the administration of the WFWRM relieves fatigue. Thirty male Kunming mice were divided into three groups, which received either intragastric administration of saline, vitamin C (100 mg/kg), or WFWRM (1.00 g/kg) every day. After 30 days of treatment, all mice exhaustively performed weight-bearing swimming. Another ten mice that did not perform swimming were treated with saline for 30 days and used as sedentary control. The antifatigue effect and biochemical oxidation phenomena were assessed in the exercise-exhausted model and sedentary controls. The histopathological changes in the liver and kidney tissues of mice were observed by performing hematoxylin-eosin (HE) staining. After 30 days of oral administration, the liver and kidney tissues of mice were healthy and show no pathological changes. Compared to the fatigue model group, WFWRM significantly increased the rota-rod time of the mice. Also, the concentrations of lactic acid (LA), blood urea nitrogen (BUN), creatine kinase (CK), and lactate dehydrogenase (LDH) in the WFWRM group significantly reduced. On the contrary, the levels of hepatic glycogen (LG), muscle glycogen (MG), and serum glucose (GLU) increased in the WFWRM group. Besides, WFWRM markedly reduced the levels of malondialdehyde (MDA) but increased the levels of glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD). Pearson correlation analysis indicated that the concentrations of the sources of energy (LG, MG, and GLU) significantly correlated with those of metabolites (BLA, BUN, CK, and LDH) and antioxidant levels (SOD, GSH-PX, and MDA). Overall, our results suggested that the supplementation of WFWRM could improve exercise capacity and relieve fatigue probably by normalizing energy metabolism and attenuating oxidation.

Study of dose-dependent actoprotective effect of ATACL on physical performancend psychoemotional status of animals under exhausting exercise

Introduction: The aim of the study was to investigate the dose-dependent actoprotective effect of ATACL on physical performance and psychoemotional status of animals under conditions of exhausting exercise.

Materials and methods: Outbred male mice (23–25 g) were used in the experiment. The test compound in various dosages, as well as the reference drug, were administered intragastrically 60 minutes before the forced swimming test for 10 days of the experiment. At the end of the physical activity, the psychoemotional status of the animals was assessed in the Open Field (OF) and Elevated plus maze (EPM) tests.

Results and discussion: In the course of the experiment, it was found that under conditions of exhausting physical execise, a smooth increase in performance was observed in the group that had received the test compound 4-hydroxy-3,5-di-tert butyl cinnamic acid (ATACL) at a dosage of 100 mg/kg for 10 days. The peak of performance was recorded on the 8th day, which was 47.3% (p&lt;0.05) higher than the physical activity of the mice treated with the reference drug ethylthiobenzimidazole hydrobromide (EBH). When assessing changes in the Open Field test, it was found that the test compound ATACL at a dosage of 100 mg/kg is also a leader in stabilizing the psychoemotional status of the animals, which is reflected in the improvement of the motor activity (the number of sectors crossed by 4.7 times (p&lt; 0.05)), exploratory activity (an increase in the number of «peeps» and rearings by 8.5 times (p&lt;0.05) and 12.7 times (p&lt;0.05), respectively) and changes in the level of anxiety (a 2.5-time decrease in the number of short-term grooming acts (p&lt;0.05)) in comparison with the negative control (NC) group. The results obtained in the EPM test are completely consistent with the results of the OF test; the most pronounced activity was observed for the ATACL compound at a dosage of 100 mg/kg.

Conclusion: Based on the combination of reproducible methods, it can be concluded that the most pronounced actоprotective effect is exerted by the compound at a dosage of 100 mg/kg, not inferior, at the same time, to the reference drug EBН.

Graphical abstract:

Blood Lactate Decreased by Foam Rolling Post-Quarter Marathon

BACKGROUND: New training methods, increased volume, the prolonged duration could induce the delayed onset of muscle soreness (DOMS), and it is associated with blood lactate (BL). Foam roller (FR) is known as a tool for active recovery. AIM: The study’s purposes are to assess the effect of the Quarter Marathon (QM) and Foam Roller (FR) on blood lactate (BL). METHODS: This is a pilot study with a quasi-repeated-measures design. Ten trained young males were voluntarily signed up using the purposive sampling technique. The Accutrend-Plus by Roche was used to measure BL. Blood lactate was measured 6 times. Combination FR protocols from the Master of Muscle and Casall were used. Repeated-measures ANOVA test was used to analyze the changes in BL. RESULTS: Blood lactate significantly increased 4.90 ± 3.0 (mmol/L) post-QM as p < 0.05, pre-test 2.23 ± 0.8 (mmol/L) compared to post-running 7.1 ± 2.6 (mmol/L). It was decreased after foam rolling activity 4.33 ± 0.7 (mmol/L), and 3.06 ± 0.5 (mmol/L) at 120 min post-running, then returned to normal after 24 h post-QM 2.44 ± 0.5 (mmol/L). CONCLUSION: Foam rolling potentially decreased BL after QM.

Continuous Glucose Monitoring in Healthy Adults—Possible Applications in Health Care, Wellness, and Sports

Introduction: Continuous glucose monitoring (CGM) systems were primarily developed for patients with diabetes mellitus. However, these systems are increasingly being used by individuals who do not have diabetes mellitus. This mini review describes possible applications of CGM systems in healthy adults in health care, wellness, and sports. Results: CGM systems can be used for early detection of abnormal glucose regulation. Learning from CGM data how the intake of foods with different glycemic loads and physical activity affect glucose responses can be helpful in improving nutritional and/or physical activity behavior. Furthermore, states of stress that affect glucose dynamics could be made visible. Physical performance and/or regeneration can be improved as CGM systems can provide information on glucose values and dynamics that may help optimize nutritional strategies pre-, during, and post-exercise. Conclusions: CGM has a high potential for health benefits and self-optimization. More scientific studies are needed to improve the interpretation of CGM data. The interaction with other wearables and combined data collection and analysis in one single device would contribute to developing more precise recommendations for users.

Delayed Rebound of Glycemia During Recovery Following Short-Duration High-Intensity Exercise: Are There Lactate and Glucose Metabolism Interactions?

Lactate constitutes the primary gluconeogenic precursor in healthy humans at rest and during low-intensity exercise. Data on the interactions between lactate and glucose metabolisms during recovery after short-duration high-intensity exercise are sparse. The aim of the present study was to describe blood glucose ([glucose]_b) and lactate ([lactate]_b) concentration curves during recovery following short-duration high-intensity exercise. Fifteen healthy Cameroonian subjects took part in the study and performed successively (i) an incremental exercise to exhaustion to determine maximal work rate (P_max) and (ii) a 2-min 110% P_max exercise after which blood lactate and glucose concentrations were measured during the 80-min passive recovery. In response to the 2-min 110% P_max exercise, [glucose]_b remained stable (from 4.93 ± 1.13 to 4.65 ± 0.74 mmol^.L⁻¹, NS) while [lactate]_b increased (from 1.35 ± 0.36 to 7.87 ± 1.66 mmol^.L⁻¹, p < 0.0001). During recovery, blood lactate concentrations displayed the classic biphasic curve while blood glucose concentrations displayed a singular shape including a delayed and transitory rebound of glycemia. This rebound began at 27.7 ± 6.2 min and peaked at 6.78 ± 0.53 mmol^.L⁻¹ at 56.3 ± 9.7 min into recovery. The area under the curve (AUC) of [lactate]_b during the rebound of glycemia was positively correlated with the peak value of glycemia and the AUC of [glucose]_b during the rebound. In conclusion, the delayed rebound of glycemia observed in the present study was associated with lactate availability during this period.

Metabolic Energy Contributions During High-Intensity Hatha Yoga and Physiological Comparisons Between Active and Passive (Savasana) Recovery

Purpose: The objective of this study was to investigate metabolic energy contributions during high-intensity hatha yoga (HIHY) and to compare changes in physiological variables between active and passive recovery methods.

Methods: The study involved 20 women yoga instructors (n = 20) who performed 10 min of HIHY (vigorous sun salutation). Upon completion, they were randomly assigned to either active (walking; n = 10) or passive (savasana; n = 10) recovery groups for a period of 10 min. During HIHY, physiological variables such as heart rate (HR_peak and HR_mean), oxygen uptake (VO_2peak and VO_2mean), and blood lactate concentrations (peak La⁻) were measured. Energetic contributions (phosphagen; W_PCR, glycolytic; W_Gly, and oxidative; W_Oxi) in kJ and % were estimated using VO₂ and La⁻ data. Furthermore, the metabolic equivalents (METs) of VO_2peak and VO_2mean were calculated. To compare different recovery modes, HR_post, ΔHR, VO_2post, ΔVO₂, recovery La⁻, and recovery ΔLa⁻ were analyzed.

Results: The results revealed that HR_peak, VO_2peak, and peak La⁻ during HIHY showed no differences between the two groups (p > 0.05). Values of HR_peak, HR_mean, METs of VO_2peak and VO_2mean, and La⁻ during HIHY were 95.6% of HR_max, 88.7% of HR_max, 10.54 ± 1.18, 8.67 ±.98 METs, and 8.31 ± 2.18 mmol·L⁻¹, respectively. Furthermore, W_Oxi was significantly higher compared with W_PCR, W_Gly, and anaerobic contribution (W_PCR + W_Gly), in kJ and % (p < 0.0001). VO_2post and recovery ΔLa⁻ were significantly higher in the active recovery group (p < 0.0001, p = 0.0369, respectively). Values of ΔVO₂ and recovery La⁻ were significantly lower in the active group compared with the passive group (p = 0.0115, p = 0.0291, respectively).

Conclusions: The study concluded that high-intensity hatha yoga which was performed for 10 min is a suitable option for relatively healthy people in the modern workplace who may have hatha yoga experience but do not have time to perform a prolonged exercise. Following active recovery, they can participate in further HIHY sessions during short breaks. Furthermore, a faster return to work can be supported by physiological recovery.

Changes in Glycolytic Pathway in SARS-COV 2 Infection and Their Importance in Understanding the Severity of COVID-19

COVID-19 is an infectious disease caused by Coronavirus 2 (SARS-CoV-2) that may lead to a severe acute respiratory syndrome. Such syndrome is thought to be related, at least in part, to a dysregulation of the immune system which involves three main components: hyperactivity of the innate immune system; decreased production of type 1 Interferons (IFN) by SARS-CoV-2-infected cells, namely respiratory epithelial cells and macrophages; and decreased numbers of both CD4+ and particularly CD8+ T cells. Herein, we describe how excessive activation of the innate immune system and the need for viral replication in several cells of the infected organism promote significant alterations in cells' energy metabolism (glucose metabolism), which may underlie the poor prognosis of the disease in severe situations. When activated, cells of the innate immune system reprogram their metabolism, and increase glucose uptake to ensure secretion of pro-inflammatory cytokines. Changes in glucose metabolism are also observed in pulmonary epithelial cells, contributing to dysregulation of cytokine synthesis and inflammation of the pulmonary epithelium. Controlling hyperglycolysis in critically ill patients may help to reduce the exaggerated production of pro-inflammatory cytokines and optimise the actions of the adaptive immune system. In this review, we suggest that the administration of non-toxic concentrations of 2-deoxy-D-glucose, the use of GLUT 1 inhibitors, of antioxidants such as vitamin C in high doses, as well as the administration of N-acetylcysteine in high doses, may be useful complementary therapeutic strategies for these patients, as suggested by some clinical trials and/ or reports. Overall, understanding changes in the glycolytic pathway associated with COVID-19 infection can help to find new forms of treatment for this disease.

Influence of endocrine disease on l-lactate concentrations in blood of ponies

Background

Blood l‐lactate concentrations are higher in people with developing or established diabetes mellitus and insulin resistance.

Objectives

To investigate whether blood l‐lactate concentrations are positively correlated with measures of insulin dysregulation (ID) or increased autumnal ACTH concentrations in ponies.

Animals

Systemically healthy client‐owned ponies (n = 101).

Methods

Prospective case‐control study. Blood samples were obtained from 101 clinically healthy ponies. Breed, weight, height, and subjective and objective measures of body condition were recorded. Blood l‐lactate, glucose, triglyceride, total adiponectin, and ACTH concentrations were measured and an oral sugar test (OST) was carried out. Correlations between blood l‐lactate and variables of endocrine health were determined.

Results

Using a seasonal cutoff point of ACTH concentrations ≥47 pg/mL, 55 ponies had increased autumnal ACTH concentrations and 45 did not. Using a basal insulin concentration of >50 μiU/mL, 42 ponies were diagnosed with ID and 58 were not. Using a 60 minutes after OST cutoff point of >45 μiU/mL, 57 ponies had ID and 37 did not. Blood l‐lactate concentrations were significantly lower in obese (average body condition score ≥ 7/9) compared to nonobese ponies (0.6 mmol/L; range, 0.0‐1.9 mmol/L vs 0.8 mmol/L; range, 0.3‐2.7 mmol/L; P = .01). No other significant correlations were detected. No differences were detected between ponies with and without increased autumnal ACTH concentrations (0.7 mmol/L; range, 0.0‐2.7 mmol/L vs 0.7 mmol/L; range, 0.3‐1.8 mmol/L; P = .84) and with and without ID (0.7 mmol/L; range, 0.3‐2.7 mmol/L vs 0.8 mmol/L; range, 0.0‐1.6 mmol/L; P = .63).

Conclusions and Clinical Importance

Results do not support an effect of endocrine status on l‐lactate concentrations in blood of ponies.

Effects of Individualized Low-Intensity Exercise and Its Duration on Recovery Ability in Adults

Exercise is recommended to increase physical health and performance. However, it is unclear how low-intensity exercise (LIE) of different durations may affect or improve recovery ability. This study aimed to investigate how LIE-duration with the same volume affects recovery ability in adults. Twenty healthy male adults participated in this study. Participants were randomly assigned to the 30-min (n = 10) or the 1-h LIE group (n = 10). The intervention included sixteen exercise sessions/four weeks with a 30-min LIE group, and eight exercise sessions/four weeks with a 1-h LIE group. Heart rate (HR) corresponding to <2 mmol∙L^-1 blood lactate (La^-) was controlled for LIE. Pre- and post-testing was conducted before and after 4-week LIE and tests included jogging/running speed (S), HR, and differences (delta; ∆) in HR and S between pre- and post-testing at 1.5, 2.0, and 4.0 mmol∙L^-1 La^-. Only the HR at 2.0 mmol∙L^-1 La^- of the 30-min LIE group was decreased in the post-test compared to the pre-test (p = 0.043). The jogging/running speed of the 1-h LIE group was improved in the post-test compared to the pre-test (p < 0.001, p = 0.006, p = 0.002, respectively). ∆HR at 2.0 and ∆S between the 30-min and 1-h LIE group at 1.5, 2.0, and 4.0 mmol∙L^-1 La^- were significantly different (p = 0.023, p < 0.001, p = 0.002, and p = 0.019, respectively). Furthermore, moderate to high positive correlations between ∆HR and ∆S of all subjects at 1.5 (r = 0.77), 2.0 (r = 0.77), and 4.0 (r = 0.64) mmol∙L^-1 La^- were observed. The 1-h LIE group showed improved endurance not only in the low-intensity exercise domain, but also in the beginning of the moderate to high-intensity exercise domain while the 30-min LIE group was not affected by the 4-week LIE intervention. Therefore, LIE (<2.0 mmol∙L^-1) for at least 1-h, twice a week, for 4 weeks is suggested to improve recovery ability in adults.

Assessment of changes in blood lactate levels in children and adolescents with type 1 diabetes during a football tournament (GoalDiab Study)

INTRODUCTION

Monitoring physical activity is a very important issue, especially in type 1 diabetes. One of the parameters assessing the intensity of exercise is the concentration of lactate in the blood. Aim of the study We assessed the intensity of PE and changes in lactate levels in children and adolescents with type 1 diabetes (T1D) during a football tournament.

MATERIAL AND METHODS

We enrolled 141 participants, the results of 70 of whom were analyzed, playing in two age categories: 10-13 and 14-17 years. Lactate levels were measured in the capillary blood before and after matches. Blood lactate of 4 mmol/l (Onset Blood Lactate Accumulation OBLA) was used as parameter indicating the prevalence of anaerobic metabolic changes.

RESULTS

The median lactate level was 1.8 mmol/l before and 4.4 mmol/l after matches (p < 0.001). The increase in lactate levels was higher in the older age category (4.3 vs. 1.8, p = 0.001) and was independent on gender (3.2 vs. 2.1, p = 0.597), personal insulin pump vs insulin pen use (3.0 vs. 1.5, p = 0.145) or training in a sports club (1.4 vs. 3.0, p = 0.084). A positive correlation was noted between increased lactate levels and age (Rs = 0.253, p = 0.034). 61% of the participants exceeded lactate levels ≥ 4 mmol/l. In univariate logistic regression analysis age was a significantly associated with lactate level ≥ 4 mmol/l [OR = 1.45 (1.08-1.95)] independent of HbA1c, gender, treatment method and training in a sports club.

CONCLUSIONS

PE intensity levels during football matches were found to be mixed aerobic-anaerobic. Increases in lactate levels were greater in the older subjects independently on the assessed factors.