Effect of an Antioxidant-rich Diet During Moderate Altitude Training

Not Applicable

Completed

• Conditions: Oxidative Stress; Adaptation Reaction; Inflammation

• Registration Number: NCT03088891
• Lead Sponsor: University of Oslo

Brief Summary

Athletes, especially in endurance sports, are at increased risk of oxidative stress and inflammation-related diseases and injuries. The production of reactive oxygen and nitrogen species (RONS) and inflammatory markers increase during exercise and especially during altitude training. Antioxidant supplementation is commonly used among athletes in the belief that it prevents oxidative stress and oxidative damage. A transient increase of RONS is however necessary to activate signaling cascades initiating training adaptation. Antioxidant supplementation has been shown to inhibit the exercise effects in several independent studies, possibly by interfering/reducing the signal cascades initiated by RONS. However, it is unknown whether a high intake of antioxidant rich foods can affect the amount of RONS, inflammation markers and/or training adaptation. The investigators want to examine whether an increased intake of natural antioxidants in the form of antioxidant-rich foods fruits, vegetables and berries, in line with the official Norwegian dietary advice can affect antioxidant status, immune function and training adaptation associated with altitude training in Norwegian elite athletes.

Detailed Description

Not available

Study Timeline

• Study Start: 2015-10
• Primary Completion: 2015-11
• Study Completion: 2015-11
• Study First Submitted: 2016-09-20
• Status Verified: 2017-03
• Study First Submitted QC: 2017-03-19
• Last Update Submitted: 2017-03-19
• Study First Posted: 2017-03-23
• Last Update Posted: 2017-03-23

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 35

Inclusion Criteria

• National team athletes, summer endurance sports

Exclusion Criteria

• Allergies in conflict with the intervention foods
• Use of medication that could affect training and performance
• Injuries that could affect training and performance

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Training adaptation	Measured one week before, and one week after the moderate altitude training camp	change in Vo2-max
Percent change in performance (sport specific tests will be aggregated to one outcome by the use of percent change)	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	Cycling: 10 000 m on a bike roller; Rowing: 2000 meter on Concept2-apparatus; Paddling: 1000 meter Concept2-apparatus; Swimming: 200 meter
Training adaptation for swimmers	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	For swimming only: 100 meter max speed

Secondary Outcome Measures

Name	Time	Method
Bone mineral density	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	measured by DXA (iDXA; GE Healthcare)
change in body composition	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	measured by DXA (iDXA; GE Healthcare)
Dietary intake (change in food and nutrient intake)	Measured one and three week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	measured by repeated 24 hour recalls
Change in biomarkers of inflammation	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	change in cytokine profile e.g. IL-6 ,TNF, CRP measured by multiplex technology
change in fat mass	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	measured by DXA (iDXA; GE Healthcare)
change in body weight	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	measured by standardized scale
Change in whole blood gene expression	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	Fasting blood samples (PAX-tubes) and samples taken after physical stress test (PAX-tubes). RNA will be isolated and gene expression measured
Change in blood lipids	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp
change in lean body mass	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	measured by DXA (iDXA; GE Healthcare)
Change in antioxidant status	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	e.g. FRAP, ORAC, dROM, isoprostanes measured by HPLC
biomarkers of antioxidant-rich foods	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	e.g. carotenoids, flavonoids measured by HPLC
Change in micronutrients	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	e.g. iron status
change response to stress test	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp
change in plasma volume	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	CO-rebreathing-method
Change hormones	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp
Change in hemoglobin	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	CO-rebreathing-method
change in blood volume	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	CO-rebreathing-method
Change in lactate	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp
Total training load	Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp	Training diary

Trial Locations

Locations (2)

University of Oslo; 🇳🇴 Oslo, Norway

Norwegian Olympic Federation; 🇳🇴 Oslo, Norway