Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: thedoc on 15/05/2012 15:38:15

Title: Could exercising too much trigger chronic fatigue syndrome?
Post by: thedoc on 15/05/2012 15:38:15

I've just finished a 17-mile run, and I'm pleasantly tired but I don't think I'm fatigued.  But can continuous straining exercise cause chronic fatigue syndrome?
Asked by Emilio Romero


                                        Visit the webpage for the podcast in which this question is answered. (http://www.thenakedscientists.com/HTML/podcasts/show/2416/)

 

Title: Could exercising too much trigger chronic fatigue syndrome?
Post by: thedoc on 15/05/2012 15:38:15

We answered this question on the show...

Esther -   That's a great question.  This illness is much more common in athletes and in fact, a teenager once told me that, she was training for the Olympics, 20% of Olympiads had had it.  I don't actually know if that's true or not, but certainly, if you are doing an awful lot of exercise and not allowing yourself time to recover, I think you are at increased risk of developing it. My service for children is in Bath and we see a lot of athletes with this illness.
Chris -   But kids don't get told to stop running around because they might get too tired.

Esther -   No, of course, and they shouldn’t be told to stop running around.  We all know that children aren’t doing enough exercise.  But when a child gets a chronic fatigue syndrome, it’s very, very difficult to treat when they're younger children because running around is so natural.  So, on a good day, they'll do loads and loads of running and on a bad day, they can't get out of bed.

Title: Re: Could exercising too much trigger chronic fatigue syndrome?
Post by: bonaboots on 16/05/2012 11:37:13

I'd like to have a reference for Esther's statement that 20% of Olympiads (sic) have had  CFS - I bet they feel super tired sometimes, after all that running and stuff, but I doubt it's the disease as defined by the most  (http://www.investinme.org/Documents/PDFdocuments/Canadian_ME_Overview_A4.pdf)accurate (http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2796.2011.02428.x/full) definitions.  There's an awful lot of obfuscation out there surrounding this disease, a bonus for those wishing to build a career with inadequate knowledge and intelligence.

Later in the interview, for example, Esther goes on to back up her genetic hypothesis with a twins study:  as usual, in this illness, they used a criteria that misdiagnoses by about 40% (see my second quote below). 

Esther's twin study (http://www.psychosomaticmedicine.org/content/63/6/936.) (I'm guessing here, there wasn't an actual reference) runs:

Quote

All full subjects completed an extensive mailed survey questionnaire that included questions on fatigue and the CFS symptom criteria according to the 1994 revised Centers for Disease Control and Prevention (CDC) research definition (9).

Fukuda 1994 specifically excludes and precludes any medical tests that would show biological evidence of physical disease.  It's not the most accurate of tools, but it is better than the Oxford, as used in the PACE study - that specifically excludes patients with a neurological disease!

Quote

This service evaluation (http://www.ncbi.nlm.nih.gov/pubmed/21132135) examined the proportion of those referred to a specialist CFS service fulfilling the Fukuda diagnostic criteria for CFS and the alternative fatigue-associated diagnoses. Of the 40% of patients subsequently found not to have CFS the most common diagnosis was fatigue associated with a chronic disease (47% of all alternative diagnoses); 20% had primary sleep disorders, 15% psychological/psychiatric illnesses and 4% a cardiovascular disorder. Thirteen per cent remained unexplained (5.2% of the total referrals).

That's a total of 40% misdiagnosed, yet we have had accurate criteria since 2003 in the Canadian Consensus (http://www.investinme.org/Documents/PDFdocuments/Canadian_ME_Overview_A4.pdf).

Woolly, very woolly business.  What's needed is some incisive bio-medical research, using the correct definition of the disease.