Mark VanNess



Dr J. Mark VanNess, PhD, is a member of the scientific advisory committee of the Workwell Foundation which specializes in two-day cardiopulmonary exercise testing (2-day CPET) for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), fibromyalgia and other fatiguing conditions. He has been working on ME/CFS since 1999, and is particularly interested in issues of autonomic dysfunction and mechanisms that produce post-exertional malaise.

Dr VanNess serves as an Associate Professor of Health, Exercise & Sport Sciences, Department of Sport Sciences, and an Adjunct Instructor at the College of Engineering, both at the University of the Pacific, Stockton, California.

Education

 * 1997-1999 - Post-Doctoral Training, Depts. of Pharmacology and Physiology, Univ. Texas Health Science Center. Gender differences in sodium-dependent hypertension
 * 1997 - PhD, Florida State University - Dissertation Title: "Role of the Paraventricular Hypothalamic Nuclei and Neuropeptide Y in the Antihypertensive Effect of Food Restriction in Aortic Coarctation Hypertension"
 * 1993 - MS, California State University Sacramento - Thesis Title: "Lactate and Metabolic Responses to Controlled Frequency Breathing During Graded Tethered Swimming"
 * 1990 - BS, Wheaton College, Illinois - Major: Exercise Physiology Minor: Biology

Notable studies

 * 2013, Discriminative validity of metabolic and Workload Measurements to Identify Individuals with Chronic Fatigue Syndrome "'Abstract - Objectives Reduced functional capacity and post-exertional fatigue following physical activity are hallmark symptoms of chronic fatigue syndrome (CFS) and may even qualify for biomarker status. That these symptoms are often delayed may explain the equivocal results for clinical cardiopulmonary exercise testing among individuals with CFS. Test reproducibility in healthy subjects is well documented. This may not be the case with CFS due to delayed recovery symptoms. The objectives for this study was to determine the discriminative validity of objective measurements obtained during CPET to distinguish individuals with CFS from non-disabled sedentary individuals.Methods Gas exchange data, workloads and related physiological parameters were compared between 51 individuals with CFS and 10 control subjects, all females, for two maximal exercise tests separated by 24 hours.ResultsMultivariate analysis showed no significant differences between controls and CFS for Test 1. However, for Test 2 the individuals with CFS achieved significantly lower values for oxygen consumption and workload at peak exercise and at the ventilatory/anaerobic threshold. Follow-up classification analysis differentiated between groups with an overall accuracy of 95.1%.Conclusions The lack of any significant differences between groups for the first exercise test would appear to support a deconditioning hypothesis for CFS symptoms. However, results from the second test indicate the presence of a CFS related post-exertional fatigue. It might be concluded that a single exercise test is insufficient to reliably demonstrate functional impairment in individuals with CFS. A second test may be necessary to document the atypical recovery response and protracted fatigue possibly unique to CFS, which can severely limit productivity in the home and workplace.'"
 * 2010, Post exertional malaise in women with Chronic Fatigue Syndrome"'Abstract - OBJECTIVE: Postexertional malaise (PEM) is a defining characteristic of chronic fatigue syndrome (CFS) that remains a source of some controversy. The purpose of this study was to explore the effects of an exercise challenge on CFS symptoms from a patient perspective. METHODS: This study included 25 female CFS patients and 23 age-matched sedentary controls. All participants underwent a maximal cardiopulmonary exercise test. Subjects completed a health and well-being survey (SF-36) 7 days postexercise. Subjects also provided, approximately 7 days after testing, written answers to open-ended questions pertaining to physical and cognitive responses to the test and length of recovery. SF-36 data were compared using multivariate analyses. Written questionnaire responses were used to determine recovery time as well as number and type of symptoms experienced. RESULTS: Written questionnaires revealed that within 24 hours of the test, 85% of controls indicated full recovery, in contrast to 0 CFS patients. The remaining 15% of controls recovered within 48 hours of the test. In contrast, only 1 CFS patient recovered within 48 hours. Symptoms reported after the exercise test included fatigue, light-headedness, muscular/joint pain, cognitive dysfunction, headache, nausea, physical weakness, trembling/instability, insomnia, and sore throat/glands. A significant multivariate effect for the SF-36 responses (p < 0.001) indicated lower functioning among the CFS patients, which was most pronounced for items measuring physiological function. CONCLUSIONS:The results of this study suggest that PEM is both a real and an incapacitating condition for women with CFS and that their responses to exercise are distinctively different from those of sedentary controls.'"
 * 2005, Exercise capacity and immune function in male and female patients with Chronic Fatigue Syndrome"'Abstract: Hyperactivition of an unwanted cellular cascade by the immune-related protein RNase L has been linked to reduced exercise capacity in persons with chronic fatigue syndrome (CFS). This investigation compares exercise capacities of CFS patients with deregulation of the RNase L pathway and CFS patients with normal  regulation, while controlling for potentially confounding gender effects. Thirty-five male and seventy-one female CFS patients performed graded exercise tests to voluntary exhaustion. Measures of peak VO2, peak heart rate, body mass index, perceived exertion, and respiratory quotient were entered  into a two-way factorial analysis with gender and immune status as independent variables. A significant multivariate main effect was found for immune status (p<0.01), with no gender effect or interaction. Follow-up analyses identified VO2 peak as contributing most to the difference. These results implicate  abnormal immune activity in the pathology of exercise intolerance in CFS and are consistent with a channelopathy involving oxidative stress and nitric oxide-related toxicity.'"
 * 2003, Subclassifying Chronic Fatigue Syndrome through exercise testing"'Abstract- Purpose: The purpose of this study was to examine physiological responses of persons with chronic fatigue syndrome (CFS) to a graded exercise test. Methods: Cardiopulmonary exercise tests were performed on 189 patients diagnosed with CFS. Based on values for peak oxygen consumption, patients were assigned to one of four impairment categories (none, mild, moderate, and severe), using American Medical Association (AMA) guidelines. A one-way MANOVA was used to determine differences between impairment categories for the dependent variables of age, body mass index, percentage of predicted VO2, resting and peak heart rates, resting and peak systolic blood pressure, respiratory quotient (RQ), and rating of perceived exertion. Results: Significant differences were found between each impairment level for percentage of predicted VO2 and peak heart rate. Peak systolic blood pressure values for the “moderate,” and “severe” groups differed significantly from each other and both other groups. The more impaired groups had lower values. The no impairment group had a significantly higher peak RQ than each of the other impairment levels (all P<0.001). Peak VO2 values were less than predicted for all groups. Compared with the males, the women achieved actual values for peak VO2 that were closer to their predicted values. Conclusion: Despite a common diagnosis, the functional capacity of CFS patients varies greatly. Stratifying patients by function allows for a more meaningful interpretation of the responses to exercise and may enable differential diagnosis between subsets of CFS patients.'"
 * 2001, Assessment of Functional Impairment by Cardiopulmonary Exercise Testing in Patients with Chronic Fatigue Syndrome"'Summary - Functional impairment in a population of patients with chronic fatigue syndrome (CFS) was determined by exercise testing. The criteria established by Weber and Janicki (1) were employed because impairment levels are based on maximal oxygen consumption. Oxygen consumption was obtained by cardiopulmonary exercise testing and was used to classify subjects according to the severity of impairment. All the subjects in this study met the CDC case definition (2) for CFS. All patients underwent at least two maximal graded exercise tests in which expired air was collected for assessment of V02max. Data are included for eighty-seven CFS patients, the highest V02 was used for determining impairment. Although all patients met the CDC case definition for CFS, only 35 (40%) would be classified as having greater than “Mild” functional impairment. The highest V02 of any of the patients in this study was 29.5 ml/kg/min, very close to what normative data predicts to be the average maximal value for the entire group. Without a sedentary control group it is unclear if the low V02 in this population is due to the pathology of CFS or results from the inactivity that accompanies the disease. However, use of maximal V02 during exercise can clearly discriminate between levels of functional impairment and may be efficacious for diagnosis of CFS. Additionally, in cases where cardiopulmonary analysis is unavailable, exercise duration on a standardized test may also be employed.'"

Clinic location
The Workwell Foundation is based in Ripon, California.

Talks & interviews

 * 2016, 12th International IACFS/ME Biennial Clinical and Research Conference, Emerging Science and Clinical Care, How Cardiopulmonary Exercise Testing Informs Pathology and Treatment(Workshop given with Christopher Snell, Ph.D. and Betsy Keller, Ph.D.)
 * 2016, Dr. Mark Van Ness, "Expanding Physical Capability in ME/CFS" Part 1 (of 2)
 * 2016, Dr. Mark Van Ness, "Expanding Physical Capability in ME/CFS" Part 2 (of 2)
 * 2014, Mark VanNess 'Exercise and ME/CFS' at Bristol Watershed
 * 2014, Speaker at the ME Research UK Stormont Parliament meeting, ‘ME in Northern Ireland: practice and research priorities’; presentation on the role of exercise and activity management for people with ME or CFS, based on his own work

Online presence

 * PubMed
 * Twitter
 * Workwell Foundation Website
 * ResearchGate

Learn more

 * 2016, Dr VanNess on recent press reports (January)