Evaluating the Legitimacy of Exercise Science

1 AMA PRA Category 1 Credit™



This talk presents an academic exercise physiologist’s perspective on the differences between mainstream exercise science and CrossFit’s exercise prescription, both for the health of the general population and for those with chronic cardiometabolic diseases.

Prof. Nathan Jenkins sets up a series of comparisons during the talk. These include (i) the Physical Activity Guidelines for Americans (PAG) vs. CrossFit’s “Fitness in 100 Words,” (ii) the relative importance of the oxidative energy supply system as a mechanistic underpinning of health benefits of exercise according to the mainstream vs. CrossFit, and (iii) CrossFit’s reliance on rigorous modern science vs. mainstream academia’s reliance on postmodern consensus science as the fundamental explanation for differences in solutions to the problem of chronic disease.

Speaker bio:

Prof. Nathan Jenkins earned his undergraduate and master’s degrees in exercise science from the University of Georgia (UGA). After completing his Ph.D. and postdoctoral training at the University of Maryland and University of Missouri, respectively, he returned to UGA as a faculty member in 2013.

Jenkins is now a tenured professor of exercise physiology at UGA. He conducts research and teaches courses on exercise, obesity, and cardiometabolic disease. He is an integrative exercise physiologist with a primary research interest in determining the impact of acute and chronic exercise on cardiovascular and metabolic health. Historically, his areas of focus in the laboratory have included hemodynamic forces, such as shear stress, as well as circulating factors — e.g., inflammatory cytokines, cell membrane microparticles, and especially circulating angiogenic cells (CACs). His current research aims to characterize the cardiovascular and metabolic responses to high-intensity functional training. The overall hypothesis driving this work is that the anaerobic demand of the exercise stimulus is directly proportional to its cardiometabolic benefits — an idea that directly contrasts the field’s consensus thinking (cf., 2018 Physical Activity Guidelines).

To date, Jenkins has published over 75 articles in the academic literature, which collectively have been cited over 2,500 times.


Learning objectives:

  1. Understand the distinction between modern and postmodern science and how this distinction can be used to contrast CrossFit’s approach with the mainstream academic approach to the systematic investigation of exercise for the purpose of improving health.
  2. Understand the difference between the Physical Activity Guidelines for Americans (PAG) and CrossFit’s emphasis on the aerobic and anaerobic energy systems.
  3. Evaluate the quality of studies included in consensus documents such as the PAG, as well as studies not included in the consensus that support alternative recommendations for higher-intensity interval training for cardiometabolic health.
  4. Understand how, in the clinical setting, to educate patients about the benefits of both aerobic and anaerobic exercise in improving cardiometabolic health.


Disclosures relevant to the speaker:

The individuals involved in course planning have no relevant financial or non-financial disclosures to report related to the planning or presentation of this course.


  • $35.00
  • 2 hours
  • Session Certificate

© 2021 CrossFit, LLC. CrossFit, Fittest on Earth, 3...2...1...Go! CrossFit Games, and Sport of Fitness are trademarks of CrossFit, LLC in the U.S. and/or other countries. All Rights Reserved.