Written by • Published 15th April 2013


Photo by Victor Freitas from Pexels 

Professor Jamie Timmons reacts to Andrew Marr’s comments about the cause of his stroke.

In an interview on Sunday, Marr blamed a bout of high-intensity exercise training for bringing on the attack.

Professor Timmons is an expert in genomics, exercise and metabolism. He also worked for eight years on cardiovascular disease prevention strategies including thrombosis and stroke in the pharmaceutical sector.

“The fact that Mr Marr had a stroke is extremely unfortunate but I see no evidence that it can be explained by the fact that he underwent short bouts of high-intensity exercise (HIT). While the two events may have broadly coincided, there is no evidence that they were causally linked. Dr Thomas Lee, from Harvard, is quoted in the Telegraph as saying that “intense exercise can be bad for you” and yet all epidemiology leads to the opposite conclusion.

“Mr Marr described how he had already had two minor strokes earlier in the year, was overworking in a stressful environment and was a previous smoker. This combination of factors could all be said to put him in the at-risk category.

“What we know as fact is that there is no clinical trial data that suggests exercise-training, intense or otherwise, either reverses these risks or creates further risk, even in people already at greater risk of a stroke. Thus his stroke could have happened at any time and is unrelated to exercise. As a matter of fact, the strongest predictor of his major stroke would be the presence of the two minor stroke episodes that he states he experienced earlier the year before. At that time presumably he was doing his long-slow jogging and yet he does not blame that for the earlier events.

“Diabetes is a serious illness and high-intensity training is a very powerful way to modulate diabetes’ risk factors in a time efficient manner, where other strategies are failing. If you are at risk of stroke, then a proper medical strategy is required to reduce the chance of thrombosis.”