Hydration and Exercise Performance in Cycling

University of Exeter

Status: Completed

Conditions: Healthy

Treatments: Dietary Supplement: Hypotonic; Dietary Supplement: Placebo; Other: Dehydrated; Dietary Supplement: Isotonic

Study type: Interventional

Funder types: Other

Identifiers

NCT03304197

170614/A/01

Details and patient eligibility

About

This study will evaluate the effects manipulating ingested fluids can have on hydration status and cycling performance. There will be 4 different conditions.

Full description

Being dehydrated can decrease endurance exercise performance. The investigators wish to test which of three drinks is most effective at re-hydrating cyclists and if this affects performance. Subjects will undertake 4 tests: once dehydrated, once hydrated with water, once hydrated with a sports-specific drink, and once with an altered sports drink. Blood samples will be taken and expired gasses will be sampled at various time points throughout the tests for later analysis. A small amount of labelled water will be consumed with each drink, a technique which will allow us to quantify the absorption of each of the drinks.

Enrollment: 15 patients

Sex: All

Ages: 18 to 50 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Highly trained cyclists (vo2max >55 ml/kg/min, PPO (peak power output) > 4 w/kg)
• Training at least 4 times a week
• Females must be taking an oral contraceptive, or using the contraceptive implant

Exclusion criteria

• Recent history of musculoskeletal injury
• Diagnosed cardiovascular disease
• Regular use of nutritional supplements that may interfere with the protocol

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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15 participants in 4 patient groups

Dehydrated

Experimental group

Description:

90 minutes cycling, without the ingestion of any fluids, followed by a 15 minute cycling time trial test

Treatment:

Other: Dehydrated

Hypotonic

Experimental group

Description:

90 minutes cycling, with the ingestion of six 250 ml carbohydrate (6g sucrose, 3g glucose) drinks, followed by a 15 minute cycling time trial test

Treatment:

Dietary Supplement: Hypotonic

Isotonic

Experimental group

Description:

90 minutes cycling, with the ingestion of six 250 ml carbohydrate (6g glucose, 3g fructose) drinks, followed by a 15 minute cycling time trial test

Treatment:

Dietary Supplement: Isotonic

Placebo

Experimental group

Description:

90 minutes cycling, with the ingestion of six 250 ml taste-matched water drinks, followed by a 15 minute cycling time trial test

Treatment:

Dietary Supplement: Placebo