Impact of Trail Running Races on Blood Viscosity and Its Determinants: Effects of Distance.

Mélanie Robert,Paul Robach,Léonard Feasson,Camille Boisson,Céline Renoux,Elie Nader,Philippe Connes,Guillaume Y Millet,Philippe Joly,Emeric Stauffer,Agnes Cibiel,Sarah Skinner

doi:10.3390/ijms21228531

Abstract

Blood rheology is a key determinant of tissue perfusion at rest and during exercise. The present study investigated the effects of race distance on hematological, blood rheological, and red blood cell (RBC) senescence parameters. Eleven runners participated in the Martigny–Combes à Chamonix 40 km race (MCC, elevation gain: 2300 m) and 12 others in the Ultra-Trail du Mont Blanc (UTMB, 171 km, elevation gain: 10,000 m). Blood samples were collected before and after the races. After the UTMB, the percentage of RBC phosphatidylserine (PS) exposure was not affected while RBC CD235a levels decreased and RBC-derived microparticles increased. In contrast, after the MCC, RBC PS exposure increased, while RBC CD235a and RBC-derived microparticles levels were not affected. The free hemoglobin and hemolysis rate did not change during the races. RBC aggregation and blood viscosity at moderate shear rates increased after the MCC. RBC deformability, blood viscosity at a high shear rate, and hematocrit decreased after the UTMB but not after the MCC. Our results indicate that blood rheology behavior is different between a 40 km and a 171 km mountain race. The low blood viscosity after the ultra-marathon might facilitate blood flow to the muscles and optimize aerobic performance.

Highlights

Red blood cells (RBC) need to be highly deformable to flow through the microcirculation and efficiently deliver their oxygen to the surrounding tissues [1,2,3]
Our results showed that blood rheology parameters and markers of red blood cell (RBC) damage are modulated differently after a 40 km or 171 km mountain race; the longer effort resulted in (1) decreased RBC deformability accompanied by an emission of RBC-related microparticles (MPs) and (2) a significant reduction in hematocrit and blood viscosity, without any sign of increased hemolysis
Eleven runners participated in the “Martigny–Combes à Chamonix” race (MCC, 40 km, elevation gain: 2300 m), and 12 runners participated in the “Ultra-Trail du Mont Blanc” race (UTMB©, 171 km, elevation gain: 10,000 m)

Summary

Introduction

Red blood cells (RBC) need to be highly deformable to flow through the microcirculation and efficiently deliver their oxygen to the surrounding tissues [1,2,3]. Any decrease in RBC deformability may affect oxygen delivery and exercise performances [4,5]. Enhanced RBC aggregation increases blood viscosity, which in turn may affect blood flow [7,8]. RBC aggregation was unaffected by a maximal exercise running test [12], a 10 km [11], or a marathon [10]. Blood viscosity was not affected by a short maximal exercise test conducted in laboratory conditions [12], a marathon [10], or a 10-km bout of running performed in either a tropical climate [11] or a neutral environment [9]

Objectives

Methods

Results

Conclusion