Exploring the Anthropometric, Cardiorespiratory, and Haematological Determinants of Marathon Performance.

AIM: We aimed to investigate the main anthropometric, cardiorespiratory and haematological factors that can determine marathon race performance in marathon runners. METHODS: Forty-five marathon runners (36 males, age: 42 ± 10 years) were examined during the training period for a marathon race. Assessment of training characteristics, anthropometric measurements, including height, body weight (n = 45) and body fat percentage (BF%) (n = 33), echocardiographic study (n = 45), cardiopulmonary exercise testing using treadmill ergometer (n = 33) and blood test (n = 24) were performed. We evaluated the relationships of these measurements with the personal best marathon race time (MRT) within a time frame of one year before or after the evaluation of each athlete. RESULTS: The training age regarding long-distance running was 9 ± 7 years. Training volume was 70 (50-175) km/week. MRT was 4:02:53 ± 00:50:20 h. The MRT was positively associated with BF% (r = 0.587, p = 0.001). Among echocardiographic parameters, MRT correlated negatively with right ventricular end-diastolic area (RVEDA) (r = -0.716, p < 0.001). RVEDA was the only independent echocardiographic predictor of MRT. With regard to respiratory parameters, MRT correlated negatively with maximum minute ventilation indexed to body surface area (VEmax/BSA) (r = -0.509, p = 0.003). Among parameters of blood test, MRT correlated negatively with haemoglobin concentration (r = -0.471, p = 0.027) and estimated haemoglobin mass (Hbmass) (r = -0.680, p = 0.002). After performing multivariate linear regression analysis with MRT as dependent variable and BF% (standardised ß = 0.501, p = 0.021), RVEDA (standardised ß = -0.633, p = 0.003), VEmax/BSA (standardised ß = 0.266, p = 0.303) and Hbmass (standardised ß = -0.308, p = 0.066) as independent variables, only BF% and RVEDA were significant independent predictors of MRT (adjusted R2 = 0.796, p < 0.001 for the model). CONCLUSIONS: The main physiological determinants of better marathon performance appear to be low BF% and RV enlargement. Upregulation of both maximum minute ventilation during exercise and haemoglobin mass may have a weaker effect to enhance marathon performance. CLINICAL TRIAL REGISTRATION: www.ClinicalTrials.gov, identifier NCT04738877.

Involvement of G-CSF, IL-6, and cortisol in transient neutrophilia after marathon races.

OBJECTIVES: The aim of this study was to clarify the mechanisms of the transient increase in neutrophils after running standard marathon races by measurement of cytokines involved in the production and survival of neutrophils, and cortisol. METHODS: Fourteen male runners who participated in the Hokkaido Marathon, which is the sole marathon race held in summer in Japan, and finished the standard marathon were analyzed sequentially from the start until a maximum of 8 days after the finish. RESULTS: Neutrophilia was observed in all runners just after they reached the goal (mean neutrophils: 13 226/µL). IL-6, G-CSF, and cortisol, but not GM-CSF, increased at the same time. Time-course studies with complete blood counts, biochemical markers, cytokines, and cortisol showed transient increases in neutrophils, monocytes, myoglobin, high-sensitivity C-reactive protein (hsCRP), G-CSF, IL-6, and cortisol. The increase in hsCRP was delayed 6 hours from the first increase in neutrophils. Correlations were observed between the neutrophil count and G-CSF, IL-6, and cortisol (G-CSF; r = .667, IL-6; r = .667, cortisol; r = .623). CONCLUSION: These results suggest that G-CSF is directly involved, and IL-6 is involved via cortisol in the transient neutrophilia that occurs after marathon races.

Effect of Multi-Strain Probiotic Supplementation on URTI Symptoms and Cytokine Production by Monocytes after a Marathon Race: A Randomized, Double-Blind, Placebo Study.

(1) Purpose: Performing strenuous exercises negatively impacts the immune and gastrointestinal systems. These alterations cause transient immunodepression, increasing the risk of minor infections, especially in the upper respiratory tract. Recent studies have shown that supplementation of probiotics confers benefits to athletes. Therefore, the objective of the current study was to verify the effects of probiotic supplementation on cytokine production by monocytes and infections in the upper respiratory tract after an acute strenuous exercise. (2) Methods: Fourteen healthy male marathon runners received either 5 billion colony forming units (CFU) of a multi-strain probiotic, consisting of 1 billion CFU of each of Lactobacillus acidophilus LB-G80, Lactobacillus paracasei LPc-G110, Lactococcus subp. lactis LLL-G25, Bifidobacterium animalis subp. lactis BL-G101, and Bifidobacterium bifidum BB-G90, or a placebo for 30 days before a marathon. Plasma cytokines, salivary parameters, glucose, and glutamine were measured at baseline, 24 h before, immediately after, and 1 h after the race. Subjects self-reported upper respiratory tract infection (URTI) using the Wisconsin Upper Respiratory Symptom Survey (WURSS-21). The statistical analyses comprised the general linear model (GLM) test followed by the Tukey post hoc and Student's t-test with p < 0.05. (3) Results: URTI symptoms were significantly lower in the probiotic group compared to placebo. The IL-2 and IL-4 plasma cytokines were lower 24 h before exercise, while the other cytokines showed no significant differences. A lower level of IL-6 produced by monocytes was verified immediately after the race and higher IL-10 at 1 h post. No differences were observed in salivary parameters. Conclusion: Despite the low number of marathoners participating in the study, probiotic supplementation suggests its capability to preserve the functionality of monocytes and mitigate the incidence of URTI.

Cardiac Biomarkers Following Marathon Running: Is Running Time a Factor for Biomarker Change?

PURPOSE: Plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin T levels show a transient increase after marathon running. The aim of this study was to investigate whether running duration influences the patterns of changes in cardiac biomarkers. METHODS: Twenty participants with fast and slow finishing times were included in the study. Blood samples were taken before the marathon race, immediately after, and 24 hours after the race. Samples were analyzed for NT-proBNP and cardiac troponin T concentration. Furthermore, a complete blood cell count was performed. RESULTS: After the marathon race, the fast and slow runners showed similar changes of NT-proBNP and cardiac troponin T (ie, a transient increase). Curve estimation regression analysis showed a curvilinear relationship (quadratic model) between running times and NT-proBNP increments immediately after the race, with less of an increase in the very fast and the very slow runners (r2 = .359, P = .023). NT-proBNP increments immediately after the race were correlated to the decline 24 hours after the marathon (r = -.612, P = .004). CONCLUSIONS: This study indicates that NT-proBNP release immediately after marathon running varies in a curvilinear fashion with running time. It is speculated that low NT-proBNP release is associated with training adaptation in most elite runners and the relatively low cardiac stress in the slowest (but experienced) runners. The combination of less adaptation and relatively large cardiac wall and metabolic stress may explain the highest NT-proBNP values in runners with average running times. In addition, NT-proBNP decrements 24 hours after the race depend primarily on the values reached after the marathon and not on running time.

Chest pain in an elite master ultra-marathon runner: a case report with a follow-up on his subsequent athletic activity.

Ultra-marathon running has enjoyed increasing popularity, with the number of master ultra-marathon runners growing annually. This study presents a case of a 51-year-old highly experienced long-distance runner (body mass: 65.1 kg, body height: 168 cm), who took part in a 48-h ultra-marathon race held in 2010, but dropped out of the competition due to acute cardiac problems manifested after 16 h of running and having completed a distance of 129 km. Two weeks following the race, intense cardiac examination was performed to explain the drop-out due to chest pain. A 12­lead electrocardiogram, a 2D transthoracic echocardiography in 3 apical projections of the left ventricle, a computed tomography of the chest, an invasive coronary angiography and a maximal oxygen uptake (VO2max) test were performed. The 12-lead ECG revealed a negative T wave in III and aVF without morphological abnormalities. The echocardiographic examinations presented a normal size and function of the heart chambers, and a normal valvar structure and function (only trivial mitral and tricuspid regurgitation was observed). The invasive coronary arteriography - due to an increased calcium score in the CT scan - showed only a non-significant systolic dynamic narrowing in the eighth segment of the left anterior descending artery due to a muscle bridge. The physical performance characteristics of the athlete and a follow-up history of his athletic activity showed that the cardiac problems he had experienced during the ultra-marathon race did not prevent him from being active in sport. Int J Occup Med Environ Health. 2020;33(4):523-34.

Relationship Between Bioimpedance Vector Displacement and Renal Function After a Marathon in Non-elite Runners.

Purpose: This study investigates the relationship between whole-body bioimpedance vector displacement, using bioelectrical impedance vector analysis (BIVA), and renal function through serum biomarkers [creatinine, urea, sodium, C-reactive protein (CRP), and creatine kinase] and urine biomarkers after a marathon. Methods: Bioimpedance measurements were taken among 19 non-elite runners at 24 h pre-race, immediately post-race, and at 48 h post-race. The bioimpedance measurements were analyzed by BIVA using the Hotelling's T2 test. The runners were divided according to a cutoff of serum creatinine level immediately post-race in G1 (<1.2 mg/dl of serum creatinine level) and G2 (≥1.2 mg/dl of serum creatinine level). The increase of the serum creatinine levels in 83% of G2 runners was related to acute kidney injury (AKI) stage 1. Results: Neither G1 nor G2 showed a creatinine clearance rate (CCr) lower than 60 ml/min. G2 showed a significant increase in CRP values at 48 h post-race vs baseline compared to G1 (P < 0.05), with over 5 mg/L (6.8-15.2) in 92% of the runners, and in CK values with over 215 U/L (282-1,882) at 48 h post-race in 100% of the runners. By BIVA, the 95% confidence ellipses of G2 showed shorter bioimpedance vectors than G1, with a noticeable minor Xc/H (P < 0.01), indicating an expansion on extracellular water and inflammation. The runners with 48 h post-race Xc/H values ≤30.5 Ω, with a decrease from -3 to -12% with respect to the Xc/H value at 24 h pre-race, indicated AKI stage 1 with 85.7% sensitivity and 91.7% specificity, with a direct correlation between AKI stage 1 with greater CRP values at 48 h post-race and bioimpedance vector displacement, but not with CK values at 48 h post-race. Conclusion: Through this data collection, it was evidenced that a transient reduction in renal function is more related to inflammatory factors than muscle damage. The BIVA method along with serum biomarkers could be used to follow up the kidney function in runners.

Effect of Acupuncture using Press Needle on Muscle Pain and Stiffness after Marathon Race-Double Blind Randomized Control Trial / 日本東洋医学雑誌

A double blind randomized control trial was performed to clarify the effects of acupuncture using a press needle on muscle pain, serum creatine kinase (CK) activity and muscle stiffness that resulted from running a marathon race. Sham press needles (placebo needles), which have the same package but without a needle tip, were developed by the acupuncture study authors. The subjects were 15 university students who participated in a marathon for the first time. Subjects were randomly assigned to two groups: the real acupuncture group and the placebo acupuncture group.<br>Both the real and the sham needles were applied to eight traditional Chinese acupoints in the lower limbs. They were applied before the start of the race and removed five days after the race.<br>Physical and biochemical examinations to determine the degree of muscle pain, CK activity, LDH isozyme, body flexion in standing position and muscle hardness were evaluated three times-before the start, after the finish, and five days after the finish.<br>Result: 1) The real acupuncture group showed less muscle pain than the placebo acupuncture group. 2) CK activity and LDH4-5 showed higher levels after the finish than before the start, but no significant difference was obtained among the groups. 3) No significant difference in time course change of the body flexion was obtained among the groups. 4) Hardness of vastus lateralis and vastus medialis showed higher levels after the finish than before the start, but no significant difference was obtained among the groups.