Effect of Glycerol Hyperhydration on Running Economy of Long-distance Runners (GHLDR)

Iberoamerican Institute of Sports Science and Human Movement

Status: Completed

Conditions: Physical Conditioning, Human; Running

Treatments: Dietary Supplement: The Effect of Glycerol Supplements

Study type: Interventional

Funder types: Other

Identifiers

NCT06818253

IICDEM-ID-001-2022

Details and patient eligibility

About

The aim of this study was to evaluate the effects of hyperhydration with glycerol on running economy (RE) in trained runners. The main questions sought to be answered are:

1. Does hyperhydration with glycerol improve running economy?
2. Are there beneficial effects on physical performance?

The researchers will conduct a clinical trial with 30 runners (15 men, 15 women) in three sessions. In the first session, VO2peak was determined and running speeds were established for sessions 2 and 3. In the second session, participants performed a stress test. In the second session, participants performed a running test in the euhydrated state under fluid restriction, and in the third session, with 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 perceived exertion (RPE) were evaluated.

Enrollment: 30 patients

Sex: All

Ages: 18 to 35 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

1. Competitive runners with a minimum record of 4.2 min/km.
2. Age between 18 and 35 years old
3. Apparently healthy athletes
4. Signature of informed consent form

Exclusion criteria

1. Presence of comorbidities that could alter the study variables (such as arterial hypertension, hyperthyroidism or heart disease).

2. Consumption of medications or stimulants (such as caffeine or diuretics) 48 hours before the tests.

3. Pregnancy.

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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30 participants in 1 patient group

Arm glycerol supplementation

Experimental group

Description:

This arm participated in a crossover design allowed minimizing interindividual variability by using each participant as their own control, evaluating the conditions of (1) hyperhydration with glycerol and (2) water restriction. The main variables evaluated were maximal oxygen consumption (VO₂max), running economy (CE), calculated using the oxygen cost unit (OCU) and caloric cost unit (CCU), as well as body temperature, perception of exertion and sweating rate.

Treatment:

Dietary Supplement: The Effect of Glycerol Supplements