Search a title or topic

Over 20 million podcasts, powered by 

Player FM logo
Artwork

Content provided by Regina Nuzzo and Kristin Sainani. All podcast content including episodes, graphics, and podcast descriptions are uploaded and provided directly by Regina Nuzzo and Kristin Sainani or their podcast platform partner. If you believe someone is using your copyrighted work without your permission, you can follow the process outlined here https://player.fm/legal.
Player FM - Podcast App
Go offline with the Player FM app!

Ultramarathons: Can vitamin D protect your bones?

58:50
 
Share
 

Manage episode 511390312 series 3646567
Content provided by Regina Nuzzo and Kristin Sainani. All podcast content including episodes, graphics, and podcast descriptions are uploaded and provided directly by Regina Nuzzo and Kristin Sainani or their podcast platform partner. If you believe someone is using your copyrighted work without your permission, you can follow the process outlined here https://player.fm/legal.

Ultramarathoners push their bodies to the limit, but can a giant pre-race dose of vitamin D really keep their bones from breaking down? In this episode, we dig into a trial that tested this claim – and found a statistical endurance event of its own: six highly interchangeable papers sliced from one small study. Expect missing runners, recycled figures, and a peer-review that reads like stand-up comedy, plus a quick lesson in using degrees of freedom as your statistical breadcrumbs.

Statistical topics

  • Data cleaning and validation
  • Degrees of freedom
  • Exploratory vs confirmatory analysis
  • False positives and Type I error
  • Intention-to-treat principle
  • Multiple testing
  • Open data and transparency
  • P-hacking
  • Salami slicing
  • Parametric vs non-parametric tests
  • Peer review quality
  • Randomized controlled trials
  • Research reproducibility
  • Statistical sleuthing

Methodological morals

  • “Degrees of freedom are the breadcrumbs in statistical sleuthing. They reveal the sample size even when the authors do not.”
  • “Publishing the same study again and again with only the outcomes swapped is Mad Libs Science, better known as salami slicing.”

References

Kristin and Regina’s online courses:

Demystifying Data: A Modern Approach to Statistical Understanding

Clinical Trials: Design, Strategy, and Analysis

Medical Statistics Certificate Program

Writing in the Sciences

Epidemiology and Clinical Research Graduate Certificate Program

Programs that we teach in:

Epidemiology and Clinical Research Graduate Certificate Program

Find us on:

Kristin - LinkedIn & Twitter/X

Regina - LinkedIn & ReginaNuzzo.com

00:00 Intro & claim of the episode
00:44 Runner’s World headline: Vitamin D for ultramarathoners
02:03 Kristin’s connection to running and vitamin D skepticism
03:32 Ultramarathon world—Regina’s stories and Death Valley race
06:29 What ultramarathons do to your bones
08:02 Boy story: four stress fractures in one race
10:00 Study design—40 male runners in Poland
11:33 Missing flow diagram and violated intention-to-treat
13:02 The intervention: 150,000 IU megadose
15:09 Blinding details and missing randomization info
17:13 Measuring bone biomarkers—no primary outcome specified
19:12 The wrong clinicaltrials.gov registration
20:35 Discovery of six papers from one dataset (salami slicing)
23:02 Why salami slicing misleads readers
25:42 Inconsistent reporting across papers
29:11 Changing inclusion criteria and sloppy methods
31:06 Typos, Polish notes, and misnumbered references
32:39 Peer review comedy gold—“Please define vitamin D”
36:06 Reviewer laziness and p-hacking admission
39:13 Results: implausible bone growth mid-race
41:16 Degrees of freedom sleuthing reveals hidden sample sizes
47:07 Open data? Kristin emails the authors
48:42 Lessons from Kristin’s own ultramarathon dataset
51:22 Fishing expeditions and misuse of parametric tests
53:07 Strength of evidence: one smooch each
54:44 Methodologic morals—Mad Libs Science & degrees of freedom breadcrumbs
56:12 Anyone can spot red flags—trust your eyes
57:34 Outro: skip the vitamin D shot before your next run

  continue reading

19 episodes

Artwork
iconShare
 
Manage episode 511390312 series 3646567
Content provided by Regina Nuzzo and Kristin Sainani. All podcast content including episodes, graphics, and podcast descriptions are uploaded and provided directly by Regina Nuzzo and Kristin Sainani or their podcast platform partner. If you believe someone is using your copyrighted work without your permission, you can follow the process outlined here https://player.fm/legal.

Ultramarathoners push their bodies to the limit, but can a giant pre-race dose of vitamin D really keep their bones from breaking down? In this episode, we dig into a trial that tested this claim – and found a statistical endurance event of its own: six highly interchangeable papers sliced from one small study. Expect missing runners, recycled figures, and a peer-review that reads like stand-up comedy, plus a quick lesson in using degrees of freedom as your statistical breadcrumbs.

Statistical topics

  • Data cleaning and validation
  • Degrees of freedom
  • Exploratory vs confirmatory analysis
  • False positives and Type I error
  • Intention-to-treat principle
  • Multiple testing
  • Open data and transparency
  • P-hacking
  • Salami slicing
  • Parametric vs non-parametric tests
  • Peer review quality
  • Randomized controlled trials
  • Research reproducibility
  • Statistical sleuthing

Methodological morals

  • “Degrees of freedom are the breadcrumbs in statistical sleuthing. They reveal the sample size even when the authors do not.”
  • “Publishing the same study again and again with only the outcomes swapped is Mad Libs Science, better known as salami slicing.”

References

Kristin and Regina’s online courses:

Demystifying Data: A Modern Approach to Statistical Understanding

Clinical Trials: Design, Strategy, and Analysis

Medical Statistics Certificate Program

Writing in the Sciences

Epidemiology and Clinical Research Graduate Certificate Program

Programs that we teach in:

Epidemiology and Clinical Research Graduate Certificate Program

Find us on:

Kristin - LinkedIn & Twitter/X

Regina - LinkedIn & ReginaNuzzo.com

00:00 Intro & claim of the episode
00:44 Runner’s World headline: Vitamin D for ultramarathoners
02:03 Kristin’s connection to running and vitamin D skepticism
03:32 Ultramarathon world—Regina’s stories and Death Valley race
06:29 What ultramarathons do to your bones
08:02 Boy story: four stress fractures in one race
10:00 Study design—40 male runners in Poland
11:33 Missing flow diagram and violated intention-to-treat
13:02 The intervention: 150,000 IU megadose
15:09 Blinding details and missing randomization info
17:13 Measuring bone biomarkers—no primary outcome specified
19:12 The wrong clinicaltrials.gov registration
20:35 Discovery of six papers from one dataset (salami slicing)
23:02 Why salami slicing misleads readers
25:42 Inconsistent reporting across papers
29:11 Changing inclusion criteria and sloppy methods
31:06 Typos, Polish notes, and misnumbered references
32:39 Peer review comedy gold—“Please define vitamin D”
36:06 Reviewer laziness and p-hacking admission
39:13 Results: implausible bone growth mid-race
41:16 Degrees of freedom sleuthing reveals hidden sample sizes
47:07 Open data? Kristin emails the authors
48:42 Lessons from Kristin’s own ultramarathon dataset
51:22 Fishing expeditions and misuse of parametric tests
53:07 Strength of evidence: one smooch each
54:44 Methodologic morals—Mad Libs Science & degrees of freedom breadcrumbs
56:12 Anyone can spot red flags—trust your eyes
57:34 Outro: skip the vitamin D shot before your next run

  continue reading

19 episodes

All episodes

×
 
Loading …

Welcome to Player FM!

Player FM is scanning the web for high-quality podcasts for you to enjoy right now. It's the best podcast app and works on Android, iPhone, and the web. Signup to sync subscriptions across devices.

 

Copyright 2025 | Privacy Policy | Terms of Service | | Copyright
Listen to this show while you explore
Play