Trial By Error: Letter to British Journal of Sports Medicine from CPET Experts

By David Tuller, DrPH

Last October, the British Journal of Sports Medicine published a short paper that was essentially a summary of Cochrane’s systematic review of graded exercise for chronic fatigue syndrome (as Cochrane calls the illness). This systematic review is problematic for a number of reasons—not least of which is that it includes the debunked PACE trial and other Oxford criteria studies.

The Oxford case definition does not require any symptoms besides fatigue for diagnosis—including the cardinal symptom of post-exertional malaise. Studies that rely on Oxford criteria samples do not represent the experiences of patients with more narrowly defined disease. Systematic reviews of flawed trials produce flawed results.

In response to the BJSM article, the experts on post-exertional malaise from University of the Pacific and the Workwell Foundation wrote a letter to the journal that has not yet been published. These investigators have documented this symptom through use of the two-day CPET test, which measures the impact of exercise. They wanted to register their evidence-based opposition to the recommendation for GET. Since the letter makes valuable points and will be useful for those seeking to rebut the BJSM paper’s fallacious claims about exercise, I am happy to post it below.


Dear Editor,

We are writing in response to the article, Exercise therapy is a beneficial intervention for chronic fatigue syndrome (PEDro synthesis), by Dannaway et al. and published on October 5, 2017 [1]. We are opposed to graded exercise therapy as a treatment for ME/CFS as recommended in this article. Our experiences working with ME/CFS patients are that graded exercise – particularly aerobic exercise–not only fails to improve function, it is detrimental to the health of patients.

The rationale behind using GET as treatment for ME/CFS is that it can reverse a cycle of inactivity and deconditioning, and subsequently reduce the fatigue and disability associated with this disease [2,3]. However, it seems counterintuitive at best to employ exercise as treatment when the hallmark of ME/CFS is a distinctive post-exertional malaise or PEM, whereby even trivial mental or physical exertion can cause a worsening of symptoms and reduced function [4]. As further noted in the 2015 National Academy of Medicine (NAM, previously called the Institute of Medicine) report, ME/CFS is a complex, multi-system disease accompanied by neurological, immunological, autonomic, and energy metabolism impairments [5]. It is not deconditioning nor are its symptoms explained by inactivity. As noted by NAM chair Dr. Ellen Clayton, the debility in ME/CFS is much greater than would be seen with deconditioning [6].

Scientific studies published by our group and other researchers have demonstrated that aerobic exercise exacerbates symptoms [7,8,9], a conclusion supported by the 2015 NAM report. This abnormal physiological response to exertion is so distinctive that many ME/CFS researchers, including the National Institute of Health’s Intramural Study [10] and Cornell’s Collaborative ME/CFS Research Center [11], use exercise, not as a therapeutic intervention, but as a way to exacerbate the illness so that it can be studied.

Studies evaluating the use of graded exercise therapy (GET) to treat ME/CFS have been criticized in part for including patients with other fatiguing conditions [12]. This led the US Agency for HealthCare Research and Quality (AHRQ) to conclude in its evidence review that once these studies were excluded there was insufficient evidence of efficacy for GET [13]. Beyond lack of efficacy there is also concern about the harm done by GET. AHRQ reported that GET was “associated with higher numbers of reported adverse events [14].” A 2017 review of patient surveys by Geraghty concurred, stating GET “brings about large negative responses in patients [15].”

In addition to research, our team has also worked for years with therapeutic exercise strategies in an attempt to help ME/CFS patients. We have tried to incorporate aerobic exercise training as a re-conditioning strategy for ME/CFS patients but it simply does not work. To the contrary, in nearly all cases, patient symptoms heighten after exercise [16].

Our research and clinical experiences engender a certain skepticism toward findings from the recent GETSET study, as expressed by experienced physical therapist Dr. Todd Davenport [17]. Further, the Centers for Disease Control and Prevention have recently removed recommendations for GET from their ME/CFS website [18].

Given what is known about the biology of ME/CFS, avoiding aerobic exercise and limiting aerobic activity whenever possible seems a more reasonable approach. This minimizes risk of relapse, the detrimental effects of which can persist for prolonged periods. Our position is that patients’ first-hand experiences can provide better evidence-based support to develop therapeutic interventions that help rather than harm. The goal of therapeutic exercise for ME/CFS patients should be to increase activity levels while reducing fatigue. We believe this is best achieved by training the anaerobic energy system, i.e., improving the body’s tolerance for and ability to clear lactate while increasing ATP in resting muscle [19].

This letter is motivated by concern about the potential harm to ME/CFS patients from aerobic exercise recommended by otherwise well-intentioned health care professionals. The views expressed here echo real-life experiences of many ME/CFS patients, which we feel, are well-supported by the scientific literature.

J. Mark VanNess, Ph.D.
Department of Health and Exercise Science
University of the Pacific
Stockton, California
Corresponding author. Email:

Todd E. Davenport, PT, DPT, MPH, OCS
Associate Professor
Department of Physical Therapy
University of the Pacific
Stockton, California

Christopher R. Snell, PhD
Scientific Director
Workwell Foundation
Ripon, California

Staci Stevens, MA
Founder, Exercise Physiologist
Workwell Foundation
Ripon, CA

Conflicts of Interest:
None declared



1. Dannaway J, New CC, New CH, et al Exercise therapy is a beneficial intervention for chronic fatigue syndrome (PEDro synthesis). Br J Sports Med Published Online First: 05 October 2017. doi: 10.1136/bjsports-2017-098407

2. Burgess M, Chalder T. PACE Manual for Therapists. Cognitive Behavioral Therapy for CFS/ME. MREC Version 2. PACE Trial Management Group. November 2004.

3. Bavinton J, Darbishire L, White PD. “PACE Manual for Therapists. Graded Exercise Therapy for CFS/ME.” MREC Version 2. PACE Trial Management Group. November 2004.

4. Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness. National Academy of Medicine. February 10, 2015. Page 86.

5. Ibid. Page 71-139

6. Tucker, M. IOM Gives Chronic Fatigue Syndrome a New Name and Definition. Medscape. February 10, 2015. Page 86.

7. Davenport T, Stevens S, VanNess M, Snell C, Little T. Conceptual Model for Physical Therapist Management of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis. Physical Therapy, April 1, 2010. Volume 90 (4) 602–614.

8. Davenport TE, Stevens SR, Baroni K, Van Ness M, Snell CR. “Diagnostic accuracy of symptoms characterizing chronic fatigue syndrome.” Disabil Rehabil September 2011; 33(19-20): 1768-75. PMID: 21208154

9. VanNess JM, Stevens SR, Bateman L, Stiles TL, Snell CR. “Post-exertional malaise in women with chronic fatigue syndrome.” J Women’s Health (Larchmt) February 2010; 19(2): 239-44.

10. NIH Intramural Study on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. National Institutes of Health.

11. Ramanujan, K. $9.4M NIH grant funds chronic fatigue syndrome center. Cornell Chronicle. September 27, 2017.

12. U.S. Agency for Healthcare Quality and Research. “Diagnosis and Treatment of Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome.” Evidence Report/Technology Assessment Number 219. U.S. Agency for Healthcare Quality and Research. December 9, 2014. Updated July 28, 2016. AHRQ Pub. No. 15-E001-EF Page 1

13.Ibid. Page 11

14. Ibid. Page vi.

15. Geraghty K, Hann M, Kurtev A. Myalgic encephalomyelitis/chronic fatigue syndrome patients’ reports of symptom changes following cognitive behavioural therapy, graded exercise therapy and pacing treatments: Analysis of a primary survey compared with secondary surveys. Journal of Health Psychology. August 29, 2017.

16. Chu L, Bateman L, Davenport T, Stein E, Stevens S. Treatment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Ann Intern Med. December 2015. 163(11):887.

17. Davenport T. Another False Start” in ME/CFS Clinical Trials: The GETSET Study. Workwell Foundation. 2017.

18. CDC ME/CFS Website. Treatments. Centers for Disease Control and Prevention. Updated July 3, 2017.

19. Davenport T, Stevens S, VanNess M, Snell C, Little T. Conceptual Model for Physical Therapist Management of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis. Physical Therapy, April 1, 2010. Volume 90 (4) 602–614.

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