This trial has been completed.

Condition hypoxia
Treatments carbohydrate energy drink, aspartame
Sponsor Medical Expeditions Ltd
Collaborator Bangor University
Start date June 2008
End date October 2008
Trial size 44 participants
Trial identifier NCT00731510, 08/WNo01/16


During a multi−week expedition to the Himalaya, we aim to investigate i) whether dietary supplementation with carbohydrate drinks and gels can improve physical performance; and ii) the underlying mechanisms for any observed changes in performance.

We hypothesise that i) carbohydrate supplementation will improve physical performance; and ii) the underlying mechanism of this improvement in performance will include maintenance of body glycogen (sugar) stores, prevention of dehydration and decrease in the incidence of acute mountain sickness.

United States No locations recruiting
Other countries No locations recruiting

Study Design

Allocation randomized
Intervention model factorial assignment
Primary purpose other
Masking participant, investigator, outcomes assessor
Carbohydrate supplements (drinks and gels)
carbohydrate energy drink PSP22 Energy, Science in Sport, Blackburn, UK
Complex carbohydrates including maltodextrin (97%) dissolved in water to make a a 10% solution, or dissolved in 25mL gels. Ad libitum. Twenty two days.
(Placebo Comparator)
Primarily Aspartame plus natural flavourings. Powder dissolved in water to provide non-distinguishable placebo drink.
aspartame Science in Sport, Blackburn, UK
Aspartame dissolved in water, ad libitum, 22 days.

Primary Outcomes

Performance (time to complete a physical performance task)
time frame: Mid study

Secondary Outcomes

Body composition
time frame: Pre, mid and post study
Hydration status
time frame: Pre, mid and post study
Body glucose stores
time frame: Pre, mid and post study
Oxygen delivery
time frame: Pre, mid and post study
Acute mountain sickness
time frame: Every day
Spontaneous physical activity level
time frame: Pre, mid and post study
Rating of perceived exertion during a stepping task
time frame: Pre, mid and post study

Eligibility Criteria

All participants at least 18 years old.

Inclusion Criteria: - a healthy enthusiasm for the outdoors and/or a passion for research in remote and difficult circumstances Exclusion Criteria: - Persons with Phenylketonuria

Additional Information

Official title MEDEX Hidden Valley 2008
Principal investigator Jamie H Macdonald, PhD
Trial information was received from ClinicalTrials.gov and was last updated in March 2017.
Information provided to ClinicalTrials.gov by Medical Expeditions Ltd.