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.