A young research assistant grips a pull up bar in a university gym.<\/p>\n
He finishes a set and his arms are already shaking.<\/p>\n
Someone fits a rigid plastic mitt over just one of his hands.<\/p>\n
No ice pack touches his arms, his neck or his face.<\/p>\n
Only his palm goes cold, and nothing else about the workout changes.<\/p>\n
Weeks later the same man is posting numbers nobody expected<\/strong>.<\/p>\n The trick lives in a patch of skin most people never think about. The palms, the soles of the feet and parts of the face are glabrous skin<\/strong>, meaning hairless, and they hide plumbing the rest of the body does not have. Direct channels called arteriovenous anastomoses allow large volumes of blood to be cooled quickly, bypassing the capillary beds found everywhere else.<\/p>\n So when researchers at Stanford<\/a> drew warm blood to the surface of the palm and chilled it, that cooled blood ran straight back toward the core. Dennis Grahn, one of the two biologists behind the work, said “we really stumbled on this by accident,” describing a project that began as a study of heat dissipation.<\/p>\n The palm works like a built in radiator<\/strong>, and nearly all mammals have such radiators: hairless areas with dense networks of veins close to the skin surface, which in bears are the pads of the feet and the tip of the snout. Why that should help a tired muscle is less settled. The lab’s proposed explanation is that cooling resets a temperature sensitive enzyme<\/strong> muscles need to generate energy, effectively clearing accumulated fatigue. That remains a hypothesis rather than a demonstrated mechanism.<\/p>\n The rig itself is unremarkable next to the result it produced. A hand goes into an airtight mitt hooked by hose to what resembles a portable cooler, and a gentle vacuum dilates the vessels of the hand, drawing warm blood from the core, where circulating water cools it. Between rounds on the bar, the subject simply rested his palm inside for a few minutes.<\/p>\n The performance effect surfaced by chance. The researchers began cooling a lab member and frequent coauthor, a self described gym rat, between sets of pull ups.<\/p>\n The device seemed to nearly erase his muscle fatigue, letting him match his first round after several more, so they started cooling him after every other set. His baseline was already unusual. He was doing roughly 180 pull ups per session<\/strong> in total, spread across repeated sets taken to exhaustion.<\/p>\n In the next six weeks, Craig Heller has said, the same man went from 180 pull ups total to over 620, a rate of improvement Heller called unprecedented. That figure comes from one highly trained volunteer, described by his own lab. Heller and Grahn have personal financial interests<\/strong> in the company developing the glove commercially.<\/p>\n Pooled group data came later, in the Journal of Strength and Conditioning Research. Over six weeks of pull up training, palm cooling increased work volume by 144 percent in pull up experienced subjects, against 5 percent over two weeks with no treatment, and by 80 percent in pull up naive subjects.<\/p>\n Over three weeks of bench press training it increased work volume by 40 percent against 13 percent with no treatment. Those groups were tiny. A review in Slate noted the 144 percent figure came from testing a handful of people even after a decade of research, with error bars of plus or minus 83 percent: before training, sessions ranged from 70 to 153 pull ups; after, from 70 to 616.<\/p>\n The glove is not magic for any cold object you grab. Blood flow to the vessels can be nearly shut off in cold weather, so making the hand too cold has almost no effect on core temperature; the cooling has to stay above the local vasoconstriction threshold. Grab an ice cube and you mostly get a cold hand<\/strong>.<\/p>\n Independent trials have also failed to reproduce the drama. A recent study found no benefit of interset palm cooling for bench press performance in resistance trained men, and a later protocol summary<\/a> reported no effect of intermittent palm or sole cooling on acute training volume, concluding current research does not support its use for enhancing resistance training volume.<\/p>\n A systematic review and meta analysis reached the same conclusion, finding neither palm nor sole cooling can be considered a valid ergogenic aid<\/strong>.<\/p>\n The same device began life doing the opposite job. Its early successes were in raising the core temperature of surgery patients recovering from anesthesia. Heat applied to cold palms opened the radiators, and warmed blood returned to the heart.<\/p>\n None of this makes a cooling glove gym equipment. The gap between one spectacular logbook and a string of null group trials is the same caution that shaped the pacing lessons behind how runners manage blisters<\/a> across long desert races.<\/p>\n What survives is the plumbing. A single patch of hairless skin really does move heat out of the body faster than the rest of it can, not unlike how sea nomad divers<\/a> carry an adaptation nobody notices until someone measures it, or how a motionless body underwater can surprise the people studying it.<\/p>\n","protected":false},"excerpt":{"rendered":" A young research assistant grips a pull up bar in a university gym. He finishes a set and his arms are already shaking. Someone fits a rigid plastic mitt over just one of his hands. No ice pack touches his arms, his neck or his face. Only his palm goes cold, and nothing else about … Read more<\/a><\/p>\n","protected":false},"author":28,"featured_media":43458,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"rank_math_focus_keyword":"lab volunteer who","rank_math_title":"A lab volunteer who could manage 180 pull ups in a session reached more than 620 in six weeks of cooling one palm between sets, though later trials have not repeated the effect","rank_math_description":"A Stanford lab experiment found cooling just the palms between sets let a research assistant's pull-up volume explode in six weeks.","footnotes":""},"categories":[25],"tags":[],"class_list":["post-43455","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-human-science"],"_links":{"self":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/43455","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/users\/28"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/comments?post=43455"}],"version-history":[{"count":1,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/43455\/revisions"}],"predecessor-version":[{"id":43459,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/43455\/revisions\/43459"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media\/43458"}],"wp:attachment":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media?parent=43455"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/categories?post=43455"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/tags?post=43455"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Why cooling only the palm reaches muscles everywhere else<\/h2>\n
The bar, the glove and a lab assistant who kept counting<\/h2>\n
What the numbers actually showed<\/h2>\n
Where a cold hand stops helping instead of helps<\/h2>\n
A natural cooling trick with a much longer resume<\/h2>\n