Effect of an Antioxidant-rich Diet During Moderate Altitude Training
- Conditions
- Oxidative StressAdaptation ReactionInflammation
- Interventions
- Other: Antioxidant-rich snacksOther: Control snacks
- 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
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 35
- National team athletes, summer endurance sports
- 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
- Arm && Interventions
Group Intervention Description Antioxidant-rich snacks Antioxidant-rich snacks The participants received antioxidant-rich snacks every day during 21 days of moderate altitude training (2300 meters above sea level). The snack included fruits and vegetable smoothies, dark chocolate, walnuts, dried fruits and berries. Control snacks Control snacks The participants received antioxidant-depleted snacks every day during 21 days of moderate altitude training (2300 meters above sea level). The snack included milkshake, and other milk-based drinks, biscuits (both sweet and salty), white chocolate.
- 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 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 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 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)
Norwegian Olympic Federation
🇳🇴Oslo, Norway
University of Oslo
🇳🇴Oslo, Norway