Muscle oxygenation profiles between active and inactive muscles with nitrate supplementation under hypoxic exercise

Figures

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  Figure 1. Experimental protocol of hypoxic trails (placebo and beetroot) in this study. Norm, normoxia; EX, exercise; HR, heart rate; bpm, beats per minute. Gray squares indicate the values at baseline, the last 5 min during submaximal exercise, and the last 30 sec at each work rate during maximal exercise. Data for the last 5 min and last 30 sec were used to calculate relative changes from the baseline values in near infrared spectroscopy signals (see Data analysis in the text).

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  Figure 2. Time‐to‐exhaustion during maximal incremental exercise under normoxia (Norm), after placebo (PL) and beetroot (BR) supplementation. Dotted lines indicate an individual data, and the solid line indicates averaged values. Values are the means ± standard deviation (SD). *P < 0.05 between PL and BR, †P < 0.05 between Norm and PL.

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  Figure 3. Time course changes in muscle deoxygenation (HHb) status in active muscles (vastus lateralis) and saturation of skeletal muscle (StO2) in inactive muscles (biceps brachii) for a typical single subject. Gray lines indicate PL and black lines indicate BR trials, respectively. a.u., arbitrary unit; EXsub, submaximal leg cycling exercise; EXmax, incremental leg cycling exercise. Arrows indicate at the point of exhaustion.

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  Figure 4. Relative changes from baseline values in each near infrared spectroscopy signal in active muscle during EXsub and EXmax between PL and BR trials. HbO2, muscle oxygenation; Total Hb, total hemoglobin. Peak indicates the individual peak work rate. Values are the means ± SD. *P < 0.05 between PL and BR within the same work rates.

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  Figure 5. Relative changes from baseline values in each near infrared spectroscopy signal in inactive muscle during EXsub and EXmax between PL and BR trials. Values are the means ± SD. * P < 0.05 between PL and BR within the same work rates.