Effects of thermoneutral water, cold-water and contrasting water temperature immersions on lower limb vein cross-section

Summary Objectives Immersion is often used within the framework of post-exercise recovery. Vascular effects connected to immersion are not all understood. In this study we examined the changes in common femoral vein and great saphenous vein cross-section during thermoneutral, cold, and contrasting (cold followed by hot) water immersion. Methods Ten professional handball players visited the laboratory on three occasions. At each visit, they completed a 20-minutes procedure in an upright position: 4-minutes in air (baseline) and then 16-minutes of lower limbs thermoneutral (∼35 °C), cold (∼12 °C) or contrasting (2:2 minutes [∼12 °C to ∼35 °C] ratio) water temperature immersion, in a random order. Common femoral vein and great saphenous vein cross-sections were evaluated using echo Doppler at baseline and at the end of the 16 minute immersion period under each condition. Results Common femoral vein cross-section was significantly increased after 16 minutes of immersion after each condition (+20.6% with thermoneutral, +14% with contrast and +7% with cold-water immersion, main effect for time P P P  u003e 0.05) during contrasting water temperature immersion and a significant decrease (−19%, P Conclusion Hydrostatic pressure, which is the same in the three immersion conditions, leads to an increase of the common femoral vein (deep venous system) cross-section no matter the water temperature. Conversely, the changes in great saphenous vein cross-section (superficial venous system) appear related to water temperature variations. This is probably related to thermoregulation mechanisms, which induce modifications in skin blood flow.