Just a guess as a fan of Wim, he could be relying on testimonial by workshop participants. Needs peer review, could be placebo, etc but that’s where science starts, noticing that some variable has an effect. Wim is not a scientist but he is excited to make claims that should be tested.
To me it makes sense, my (non-expert) understanding is those diseases are cases where the body is attacking itself. The immune system is a balancing act, it is blind to what is really happening, it has to rely on a threshold of when to respond to what it senses as danger. When I breath hold and/or expose myself to cold, I feel like I am giving my body a small taste of death, recalibrating my body to what danger feels like.
To me it makes sense, my (non-expert) understanding is those diseases are cases where the body is attacking itself. The immune system is a balancing act, it is blind to what is really happening, it has to rely on a threshold of when to respond to what it senses as danger. When I breath hold and/or expose myself to cold, I feel like I am giving my body a small taste of death, recalibrating my body to what danger feels like.