Experts

What the experts actually said.

Public statements about the Norwegian 4x4 and VO2 max, accurately quoted or paraphrased and linked to their sources. None of the people cited are affiliated with Viking 4x4.

What the Experts Say About VO2 Max and the 4x4

What Peter Attia, Rhonda Patrick, Layne Norton, Mike Joyner, and Benjamin Levine have said publicly about VO2 max and 4x4 interval training.

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What Dr. Rhonda Patrick Says About the Norwegian 4x4

What Rhonda Patrick has said publicly about the Norwegian 4x4 and VO2 max — her X post, podcast episodes, and cautions, with links to sources.

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Peter Attia on VO2 Max: Why He Calls It the Best Predictor

Peter Attia's public case that VO2 max predicts mortality better than smoking or diabetes, and the 4x4-style interval protocol he prescribes.

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