Numerous exercise abnormalities been found in Chronic Fatigue Syndrome (CFS)
One curious omission from this interesting review[1] is Chronic Fatigue Syndrome (CFS), which is also sometimes known as Myalgic Encephalomyelitis (ME). An abnormal response to physical activity is an essential part of widely used ME/CFS clinical criteria for adults[2] and children[3]. The most frequently used research criteria for CFS [4] require that patients, along with suffering from chronic debilitating fatigue lasting at least 6 months, have at least 4 out of a list of 8 symptoms, one of which is “postexertional malaise lasting more than 24 hours.”
There is a growing body of research on abnormal responses to exercise in CFS. A recent review[5] covers the issue in a fairly comprehensive manner - here's a summary: “Exertion induces post-exertional malaise with a decreased physical performance/aerobic capacity, increased muscoskeletal pain, neurocognitive impairment, "fatigue", and weakness, and a long lasting "recovery" time. This can be explained by findings that exertion may amplify pre-existing pathophysiological abnormalities underpinning ME/CFS, such as inflammation, immune dysfunction, oxidative and nitrosative stress, channelopathy, defective stress response mechanisms and a hypoactive hypothalamic-pituitary-adrenal axis.”
High rates of adverse reactions to graded exercise programs have been reported in patients with CFS – sometimes 50% or greater[6].
CFS remains a fairly poorly understood condition. There is increasing evidence that CFS is heterogeneous and this heterogeneity could be of relevance to therapeutic programs involving exercise [7,8]. Those interested in researching abnormal responses to physical activity, including dysregulated inflammatory responses, could find much of interest if they chose to study CFS.
References:
1) Cooper DM, Radom-Aizik S, Schwindt C, Zaldivar F Jr. Dangerous exercise: lessons learned from dysregulated inflammatory responses to physical activity. J Appl Physiol. 2007 Aug;103(2):700-9. Epub 2007 May 10.
2) Carruthers BM, Jain AK, De Meirleir KL, Petersn DL, Klimas MD, Lerner AM, Bested AC, Flor-Henry P, Joshi P, Powles ACP, Sherkey JA, van de Sande MI (2003). "Myalgic encephalomyelitis.chronic fatigue syndrome: Clinical working definition, diagnostic and treatment protocols". Journal of Chronic Fatigue Syndrome 11 (1): 7-36.
3) Jason LA, Porter N, Shelleby E, Bell DS, Lapp CW, Rowe K, & De Meirleir K. (2008). A case definition for children with Myalgic Encephalomyelitis/ chronic fatigue syndrome. Clinical Medicine: Pediatrics, 1, 53-57.
4) Fukuda K, Straus SE, Hickie I, Sharpe MC, Dobbins JG, Komaroff A. The chronic fatigue syndrome: a comprehensive approach to its definition and study. International Chronic Fatigue Syndrome Study Group. Ann Intern Med. 1994 Dec 15;121(12):953-9.
5) Twisk FN, Maes M. A review on cognitive behavorial therapy (CBT) and graded exercise therapy (GET) in myalgic encephalomyelitis (ME) / chronic fatigue syndrome (CFS): CBT/GET is not only ineffective and not evidence-based, but also potentially harmful for many patients with ME/CFS. Neuro Endocrinol Lett. 2009;30(3):284-99.
6) Kindlon T, Goudsmit EM. Graded exercise for chronic fatigue syndrome: too soon to dismiss reports of adverse reactions. J Rehabil Med. 2010 Feb;42(2):184; author reply 184-6.
7) Jason LA, Corradi K, Torres-Harding S, Taylor RR, & King C. Chronic fatigue syndrome: The need for subtypes. Neuropsychology Review 2005, 15, 29-58.
8) Kindlon T. Stratification using biological factors should be performed in more CFS studies. Psychol Med. 2010 Feb;40(2):352. Epub 2009 Oct 12.
