Effect of Acute Dietary Nitrate Supplementation on the Changes in Calf Venous Volume during Postural Change and Skeletal Muscle Pump Activity in Healthy Young Adults

TL;DR

This study found that drinking beetroot juice boosts nitric oxide activity but does not affect blood pooling or muscle pump action in the calf during posture changes.

Contribution

The study demonstrates that acute dietary nitrate supplementation increases plasma nitrate but does not alter venous volume changes during postural shifts or muscle activity.

Findings

Plasma nitrate concentration was higher after beetroot juice consumption compared to the control.

Calf venous volume changes during posture shifts and tiptoe maneuvers were not significantly different between the groups.

Acute nitrate supplementation does not affect venous pooling or skeletal muscle pump activity in healthy young adults.

Abstract

Dietary nitrate (NO3−) supplementation is known to enhance nitric oxide (NO) activity and acts as a vasodilator. In this randomized crossover study, we investigated the effect of inorganic NO3− supplementation on the changes in calf venous volume during postural change and subsequent skeletal muscle pump activity. Fifteen healthy young adults were assigned to receive beetroot juice (BRJ) or a NO3−-depleted control beverage (prune juice: CON). Two hours after beverage consumption, the changes in the right calf volume during postural change from supine to upright and a subsequent right tiptoe maneuver were measured using venous occlusion plethysmography. The increase in calf volume from the supine to upright position (total venous volume [VV]) and the decrease in calf volume during the right tiptoe maneuver (venous ejection volume [Ve]) were calculated. Plasma NO3− concentration was higher in the BRJ group than in the CON group 2 h after beverage intake (p < 0.05). However, VV and Ve did not differ between CON and BRJ. These results suggest that acute intake of BRJ may enhance NO activity via the NO3− → nitrite → NO pathway but does not change calf venous pooling due to a postural change or the calf venous return due to skeletal muscle pump activity in healthy young adults.

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