General.Data. Proyect Glycerol.csv

Objective
Endurance athletes face significant water loss during exercise, which can impact performance and increase the risk of dehydration. Glycerol hyperhydration has been explored as a strategy to improve hydration status before competition, especially when hydration opportunities are limited. The aim of this study was to evaluate the effects of glycerol hyperhydration on running economy (RE) in trained runners.

Methods
A clinical trial was conducted with 30 runners (15 men, 15 women) across three sessions. The first session involved determining VO2peak and setting running speeds for sessions 2 and 3. In the second session, participants performed a running test in a euhydrated state under fluid restriction, and in the third session, they received glycerol supplementation (22 ml/kg sports drink + 1.2 g/kg glycerol). Variables such as caloric cost unit (CCU), oxygen cost unit (OCU), heart rate (HR), body temperature (BT), and rating of perceived exertion (RPE) were assessed. Effect size computed as standardized mean differences (Cohen’s d).

Results
Glycerol supplementation significantly improved running economy, reducing CCU (p = 0.025, d = 0.43), OCU (p = 0.011, r = 0.46), HR (p = 0.029, d = 0.42), and RPE (p = 0.003, d = 0.60). Additionally, although BT slightly decreased (p = 0.053, d = 0.37), it did not reach statistical significance, suggesting a trend toward lower body temperature, potentially reflecting enhanced thermoregulation.
Conclusions
These findings suggest that glycerol supplementation improves the metabolic variables associated with running economy, such as the CCU and OCU, as well as cardiovascular responses and the RPE in trained runners.