Effect of an Antioxidant-rich Diet During Moderate Altitude Training (ALTAX)

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

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.

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.

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.

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)

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

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

Cycling: 10 000 m on a bike roller; Rowing: 2000 meter on Concept2-apparatus; Paddling: 1000 meter Concept2-apparatus; Swimming: 200 meter

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Koivisto-Mork AE, Paur I, Paulsen G, Garthe I, Raastad T, Bastani NE, Blomhoff R, Bohn SK. Dietary Adjustments to Altitude Training in Elite Endurance Athletes; Impact of a Randomized Clinical Trial With Antioxidant-Rich Foods. Front Sports Act Living. 2020 Aug 26;2:106. doi: 10.3389/fspor.2020.00106. eCollection 2020.