Hemorheologic effects of light prolonged 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.

Exercise intensity criteria for routine rehabilitation therapy for stroke patients

[Purpose] The aim of this study was to observe the relationships among heart rate, rate of perceived exertion, and oxygen consumption in stroke patients and the effectiveness of improving aerobic capacity during routine rehabilitation therapy. [Subjects and Methods] Thirty-six stroke patients participated in the study. A K4b² pulmonary function device was used to record heart rate (beats per minute), oxygen consumption (Equation Section (Next)ml·min⁻¹·kg⁻¹), and rate of perceived exertion. Results were recorded after completing the following activities continuously: (1) silent sitting, (2) sit-to-stand transfers, (3) hip extension while standing against a wall, (4) weight loading on the affected leg, (5) upward and downward leg movements on a stall bar, (6) walking up and down a flight of stairs, and (7) a 60-meter walk. Correlation analyses were performed to demonstrate the relationship of oxygen consumption with HR and RPE. [Results] Moderate correlation was found between HR and oxygen consumption, and low correlation was found between rate of perceived exertion and oxygen consumption. The routine rehabilitation therapy could reduce the accumulation of lactate. [Conclusion] HR is a better index than rate of perceived exertion in evaluating exercise intensity in stroke patients. The routine rehabilitation therapy can improve the aerobic capacity of stroke patients.

Time course of hemorheological alterations after heavy anaerobic exercise in untrained human subjects

The time course of hemorheological alterations was investigated after heavy anaerobic exercise in untrained male human subjects. The Wingate protocol was performed by each subject, and blood lactate, red blood cell (RBC) deformability and aggregation, white blood cell (WBC) activation, and several hematological parameters were investigated during 24 h after the exercise and compared with preexercise values. Compared with the preexercise value, blood lactate level was found to be approximately 10-fold higher immediately after the exercise. There was a transient, significant increment of RBC and WBC counts immediately after exercise that was followed by a decrement of RBC count. There was a second increase of WBC count, accompanied with increased percentages of granulocytes and granulocyte activation, starting 45 min after exercise. RBC deformability was found to be impaired immediately after exercise and remained reduced for at least 12 h; RBC aggregation was also found to be decreased after exercise, with the onset of this decrease delayed by 30 min. The results of this study indicate that a single bout of heavy anaerobic exercise may induce significant hemorheological deterioration lasting for up to 12 h and thus suggest the need to consider such effects in individuals with impaired cardiovascular function.