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Completed

NCT Number: NCT03088891

Effect of an Antioxidant-rich Diet During Moderate Altitude Training

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.

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Key information

Age range

16 year–42 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Norwegian Olympic Federation, Oslo, Norway

Loading trial locations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Antioxidant-rich snacks

Other

Bama Smoothies (Bama, Oslo, Norway), Freia Premium Dark Chocolate (Freia, Oslo, Norway), Walnuts (Eldorado, Norway), Dried fruits and berries (Cranberries, Gojiberries, apricots)(Bama, Oslo, Norway and Rema 1000, Norway)

Control snacks

Other

Milkshake (Tine, Oslo, Norway), YT restitusjonsdrikk (Tine, Oslo, Norway), Bixit (Sætre, Oslo, Norway), Ritz (Mondelez, Oslo, Norway), White chololate (Freia, Oslo, Norway)

Primary outcomes

  1. Percent change in performance (sport specific tests will be aggregated to one outcome by the use of percent change)

    Time frame: 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

  2. Training adaptation

    Time frame: Measured one week before, and one week after the moderate altitude training camp

    change in Vo2-max

  3. Training adaptation for swimmers

    Time frame: 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 outcomes

  1. Change in biomarkers of inflammation

    Time frame: 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

  2. change in lean body mass

    Time frame: 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)

  3. Bone mineral density

    Time frame: 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)

  4. change in fat mass

    Time frame: 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)

  5. change in body composition

    Time frame: 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)

  6. change in body weight

    Time frame: 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

  7. Dietary intake (change in food and nutrient intake)

    Time frame: 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

  8. Change in antioxidant status

    Time frame: 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

  9. biomarkers of antioxidant-rich foods

    Time frame: 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

  10. Change in whole blood gene expression

    Time frame: 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

  11. Change in blood lipids

    Time frame: Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp

  12. Change hormones

    Time frame: Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp

  13. Change in micronutrients

    Time frame: 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

  14. change response to stress test

    Time frame: Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp

  15. Change in hemoglobin

    Time frame: 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

  16. change in blood volume

    Time frame: 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

  17. change in plasma volume

    Time frame: 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

  18. Change in lactate

    Time frame: Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp

  19. Total training load

    Time frame: Measured one week before, during (in week 1 and 3 of the camp) and one week after the moderate altitude training camp

    Training diary

Sponsors and collaborators

Lead sponsor

University of Oslo

Other

Collaborators

  • Norwegian Olympic Federation, Oslo, Norway
  • Norwegian School of Sport Sciences

Registry information

Official study title

The Effect of an Increased Intake of Antioxidant-rich Foods on Training Adaptation, Redox-balance and Inflammation Among Elite Athletes During a Moderate Altitude Training Camp

Acronym: ALTAX

Important dates

Study start
2015
Primary completion
2015
Study completion
2015
First posted
Mar 23, 2017
Registry last updated
Mar 23, 2017

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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