ππππ«πππππ #vitaminD paper.
"The originally-published data are inaccurate and a complete set of corrected data is not available."
βΎAnd my "Letter to The Editor" in which I describe in more detail the most serious/perplexing issues: tinyurl.com/2p8f5mj7
π§΅2/13
I learned about this study after Dr. Rhonda Patrick (Ph.D. in biomedical science) shared it among her nearly 400,000 Twitter followers who, in turn, retweeted it more than 500 times. π§΅3/13
The authors claim that 60 days of supplementation with low-dose vitamin D increased absolute VO2max (L/min) by 28%. Not only is this unprecedented for such an intervention but there was no associated change in relative VO2max (mL/kg/min). π§΅4/13
The authors didn't report body mass (!?). Still, basic arithmetic shows that an increase in absolute VO2max of this magnitude, without change in relative values, requires an increase in body mass of ~18 kg (~40 lbs) over 60 days. Physiologically impossible. π§΅5/13
The authors consider these responses authentic. π§΅6/13
The other main outcome was a unilateral increase in handgrip strength with vitamin D (increased strength in the left but not the right arm). Again, the authors claim this result is authentic but provide no valid explanation. π§΅7/13
Crucially, they tested for differences using ππ π₯πππ¬π 14 t-tests without correcting for familywise error. This increases the probability of a false-positive to >ππ%. The difference in forearm strength is not significant after a Bonferroni adjustment (p=0.098)π§΅8/13
Reporting of data was also inconsistent. Instead of reporting variance as IQR, the authors opted to report median (min-max). However, Table 2 clearly shows median (25th-75th percentiles), indicating that the authors are trying to conceal outliers in the data. π§΅9/13
There were many other concerns with the manuscript, including numerous occasions in which the authors cited references that were non-existent or those that did not support their assertions. See "Letter" for specific examples. π§΅10/13
It's a symptom of a broader problem in science, but we can learn important lessons: 1) Be skeptical of extraordinary claims unless supported by extraordinary evidence; 2) The devil is in the detail; 3) We must read beyond headlines & abstracts before sharing to social media.13/13
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If you're training for #muscle strength, power, or hypertrophy, STOP ice bathing after your sessions. It's almost certainly diminishing your returns. 1/5 #strength#training Evidence summary ->
Exhibit 1. Cold-water immersion blunts the muscle's anabolic response to strength training. @JPhysiol@LlionARoberts 2/5
Exhibit 2. Cold-water immersion lowers the muscle's capacity for myofibrillar protein synthesis after resistance exercise. @JPhysiol@27CJ 3/5
In Oct 2021, I had a routine blood test that revealed elevated liver enzymes. A later blood test with a different doctor showed the liver panel was "elevated and worsening", more than double the normal range for some variables. 2/5
A series of additional tests, including abdominal ultrasound, were negative. Physician referred me to a gastroenterologist who suggested (an invasive) liver biopsy. However, before the next blood test, I stopped exercising for 7 days. 3/5
I was asked recently to provide some examples of health and fitness marketing that makes false claims and/or exploits human biases. I came up with a billion examples. Here are just 6:
The official #Olympics website endorsing #cryotherapy as an effective form of post-exercise recovery. Despite the fact the literature is very unimpressive, littered with low-quality studies, and tiny effects. #IOC