The bioenergetics of running
“Three things are needed to build and maintain a living system: material, information (pattern), and energy. There is no life without energy”
Albert Szent-Györygi The Living State (1972)
‘It has always been my view that a knowledge of physiology and biochemistry makes exercise more interesting for a runner. The current running boom (for some almost an addiction, but if so the only healthy addiction I know) makes necessary for the intelligent runner to know more about his body, how hard he should train, when he should yield to fatigue and what should be his diet and what are the limiting factors of his performance…’ Sir Roger Bannister MD.
The BTR bioenergetics education has been designed in the same spirit as the BTR biomechanics education; with the intention of providing a small island of coaching wisdom in a ‘boggy’ area notoriously flooded with information i.e. training and diet.
‘The Runner’ by Eric Newsholme and Tony Leech was the starting point in the creation of BTR’s ‘bioenergetics’ and although first published in 1983 the knowledge contained within this small book and it’s 150 pages is still very relevant today (as the preface from Sir Roger Bannister above indicates). Here are a few examples of the simple Figures used and BTR’s interpretation of them.
Running A Marathon:
A healthy-human body contains enough stored glucose (glycogen) to provide energy for approximately 90 mins of running. Consequently, the body must use an alternative fuel source to provide energy for runs of longer duration. The substrate of choice is fatty acids. (*Gluconeogenesis from structural proteins is an ‘expensive’ option that the body will try to avoid whenever possible)
Up to the 17th-18th mile, the average runner has been oxidising both fatty acids and glucose. The muscle glycogen stores are now depleted, and fatty-acid oxidation cannot provide ATP at the rate required to maintain the desired muscle action and running speed, consequently the pace drops and the pain increases.
Fatty acids; A vicious cycle:
Using fatty acids as as a fuel is a ‘survival’ strategy designed to conserve enough liver glycogen to prevent hypoglycemia and maintain brain function. The glucose-sparing effect of fatty acid oxidation observed in well-trained distance runners is also consistently observed in shock, starvation, heart failure and diabetes and is known as the ‘Randle cycle’.