engleski

MICROVASCULAR REACTIVITY IN HEALTHY SEDENTARY SUBJECTS AND TRAINED ROWERS BEFORE AND AFTER EXPOSURE TO ACUTE EXHAUSTING ROWING TRAINING

Objective The aim of our study was to determine: 1) whether there is the difference in baseline vascular reactivity between sedentary healthy subjects (Sedentary) and trained rowers (Trained) and 2) to test the impact of AE rowing training on microvascular reactivity in these two groups. Design and Methods Healthy lean Sedentary (N=8) and Trained male rowers (N=8 ) volunteered in this study. All participants underwent a single progressive rowing training to maximal exhaustion. Skin microvascular post occlusive reactive hyperemia (PORH) (indicator of endothelial function) was assessed by laser Doppler flowmetry (LDF) before and after AE. ABP, heart rate and oxygen saturation, plasma glucose, C reactive protein (CRP) and lactate levels, as well as, arterial blood gas analysis and acid base status were measured before and after AE. Body mass index (BMI) and waist to hip ratio (WHR) were measured in each subject. Results All subjects were age-matched males, with no difference in BMI, WHR, control ABP and heart rate between groups. At baseline, Trained had significantly higher PORH compared to Sedentary. Interestingly, PORH was significantly impaired in Trained after AE, while AE didn't induce any significant change in PORH in Sedentary. During AE systolic blood pressure significantly increased in both groups, but more prominent in Trained compared to Sedentary. Serum lactate and glucose levels significantly increased, and metabolic acidosis occurred, while oxygen saturation decreased after AE in both groups. CRP significantly increased in Sedentary after AE. Conclusions Significantly better microvascular reactivity in Trained rowers confirms that chronic exercise may improve endothelial function. Impaired microvascular reactivity in trained rowers but not in sedentary subjects after AE occurs possibly due to 1) higher transient increase in arterial pressure that occurred in trained rowers and/or 2) change in sensitivity to metabolic acidosis during exertion in athletes.

microvascular reactivity ; acute exercise ; rowers ; laser Doppler flowmetry

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