Two or three minutes under cold (or at least colder) is an awesome morning wakeup IME. You can run hot afterwards if you like.
Seriously, you[1] are not going to induce hypothermia in five or ten minutes of cold water. That’s just silly. Hypothermia is not a significant risk of ten minutes’ swimming in a non-heated pool, for example.
(If you’re doing the New Year’s Day Alcatraz Swim, of course, you may care to make sure you’re warmed properly afterwards.)
Two or three minutes under cold (or at least colder) is an awesome morning wakeup IME.
The effect is probably mostly Mammalian diving reflex, which is triggered by colder-than-21°C water contacting the face, with other factors (such as showering your whole body) much less relevant.
Two or three minutes under cold (or at least colder) is an awesome morning wakeup IME. You can run hot afterwards if you like.
Seriously, you[1] are not going to induce hypothermia in five or ten minutes of cold water. That’s just silly. Hypothermia is not a significant risk of ten minutes’ swimming in a non-heated pool, for example.
(If you’re doing the New Year’s Day Alcatraz Swim, of course, you may care to make sure you’re warmed properly afterwards.)
[1] in the general case
The effect is probably mostly Mammalian diving reflex, which is triggered by colder-than-21°C water contacting the face, with other factors (such as showering your whole body) much less relevant.
Seems to have a lot more effect when it’s a shower, not just cold water on my face.