Case TS-5FEEC80F23 Jul 2026StudyCompound claim

A University of Colorado Boulder study suggests the Reverse Cowgirl position burns more calories than a 50-minute Pilates workout. Over eight weeks, researchers observed 214 adults. Compared to a Pilates control group, the other group showed higher energy expenditure per session, greater core and lower-body muscle activation, and…

Plain restatementAn Instagram post attributes to the University of Colorado Boulder an 8-week, 214-adult controlled study finding that the reverse cowgirl sexual position produces higher energy expenditure, more core/lower-body muscle activation, and more fatigue than a 50-minute Pilates session.

UnverifiedConfidence not recorded
What this verdict means →

There is no evidence that the University of Colorado Boulder conducted any study finding that the "reverse cowgirl" sexual position burns more calories than a 50-minute Pilates workout. The alleged 214-participant, 8-week trial does not appear on CU Boulder's news site, on PubMed, in any preprint server, or in any mainstream news coverage. The viral post comes from an entertainment Instagram account, not a scientific outlet. In fact, the caloric-burn estimates that do exist in the public record place reverse cowgirl among the lowest-burn sexual positions, while Pilates sessions are commonly estimated at several hundred calories, which is the opposite of what the post claims. The specific numbers, methodology, and conclusions in the post appear to be fabricated. Treat the claim as false.

The drift / as claimed vs as evidenced

[drifted from the evidence:] A University of Colorado Boulder study [drifted from the evidence:] suggests the Reverse Cowgirl position [drifted from the evidence:] burns more calories than a 50-minute Pilates workout. Over eight weeks, researchers observed 214 adults. Compared to a Pilates control group, the other group showed higher energy expenditure [drifted from the evidence:] per session, greater core and lower-body muscle activation, and [drifted from the evidence:] increased fatigue [drifted from the evidence:] while exercising less time.


[added by the neutral restatement:] An Instagram post attributes to the University of Colorado Boulder [added by the neutral restatement:] an 8-week, 214-adult controlled study [added by the neutral restatement:] finding that the reverse cowgirl [added by the neutral restatement:] sexual position [added by the neutral restatement:] produces higher energy expenditure, [added by the neutral restatement:] more core/lower-body muscle activation, and [added by the neutral restatement:] more fatigue [added by the neutral restatement:] than a 50-minute Pilates session.

Red-tinted words in the claim drifted from the evidence. Green-tinted words are what a neutral restatement needs.

The trace / claim to source

Source
Instagram post by @spottedhollywood, a general celebrity/entertainment page.
Source
University of Colorado Boulder official news site (colorado.edu/today) and CU recreation/theatre-dance Pilates pages
Source
PubMed / Google Scholar type searches for "reverse cowgirl" combined with "energy expenditure," "Pilates," "214 adults," or "8 weeks"
Source
General web search for the viral claim wording
◌ No primary source reached
What is true
  • The University of Colorado Boulder is a real institution that offers Pilates classes and hosts exercise-science teaching.
  • "Reverse cowgirl" is a real sexual position discussed in mainstream health media.
  • Some prior estimates of caloric burn during various sexual positions do exist in the public record, though from commercial calculators and small studies, not from CU Boulder. **WHAT IS MISLEADING / FABRICATED:**
  • **Fabricated source:** No CU Boulder study on this topic exists in any searchable database.
  • **Fabricated statistics:** The "214 adults" sample, "8 weeks," "50-minute Pilates control," and the described outcomes (higher energy expenditure, greater muscle activation, more fatigue in less time) do not appear in any locatable paper.
  • **Directionally contradicted by existing evidence:** Where estimates for reverse cowgirl caloric burn do exist, they place the position among the lowest-burn options, and Pilates estimates are far higher than any figures associated with sexual activity.
  • **Marketing-style framing:** The closing sentence about "sparking interest in workouts combining strength, coordination, and endurance" is promotional language, not scientific reporting.
What is uncertain
  • Whether the Instagram post is intended as satire, engagement bait, or AI-generated filler content. The source account is an entertainment page, not a science publisher, and does not label itself satire. ---
Evidence summary

After multiple searches, no trace exists of any University of Colorado Boulder study on the "reverse cowgirl" position, its caloric expenditure, or a comparison with Pilates. CU Boulder's official news feed for 2026 lists unrelated research (for example, a research team including scientists and engineers from CU Boulder, CU Anschutz and Colorado State University has developed a suite of new therapies that prompt aging or damaged joints to repair themselves within weeks, according to animal studies ), and the university's Pilates-related pages are all instructional program listings, not research outputs. The only established research on caloric burn during sexual activity comes from unrelated commercial or small academic sources, and those actually rank reverse cowgirl among the *lowest*-burn positions, not the highest. For example, reverse cowgirl and cowgirl positions burn the fewest calories at 16 and 13 calories per 10-minute session , and a separate calculator-based estimate found while the Cowgirl burns just 39 calories, flip things round to Reverse Cowgirl and you'll shed an extra nine calories per half hour. Both are relatively low impact, taking the lowest and second-lowest spots on the list . Meanwhile Pilates itself is commonly credited with substantially higher session burn: Burn 250–450 calories with Pilates . Those numbers point in the opposite direction of the viral claim.

Complete reasoning
Multiple targeted searches, including on CU Boulder's own domain, PubMed, and general web queries with the specific numbers in the claim, return zero results matching this alleged study. The specific figures (214 participants, 8 weeks, Pilates control) appear nowhere outside the viral post and its reposts. The only real-world caloric-burn estimates for reverse cowgirl point in the opposite direction of the claim (low burn), while Pilates burn estimates are much higher. Since the claim cites a specific institution, specific sample, specific duration, and specific comparator, and none of these can be located, this is a fabrication, not merely misleading framing of a real study. ---
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