May 16, 1996. Copyright, 1996, Graphic News. All rights reserved

UNRAVELLING THE KEY TO SPORTING SUCCESS
By Laura Spinney, Science Editor

LONDON, May 16, Graphic News- With nine weeks to go to the start of the 1996 Olympics, scientists in London believe they are a step closer to unravelling the biochemical mechanisms that take place in muscles to provide an athlete with enough force to sprint for 100 metres.

A 100 metre sprint requires a large burst of energy over a short period of time. Some of that energy is provided by protein filaments in muscle cells when they are fuelled by a substance called adenosine triphosphate, or ATP. Through a process called hydrolysis, ATP is broken down into ADP (adenosine diphosphate), releasing energy even in the absence of oxygen. At the same time, the structure of the filaments, and hence of muscle fibres, changes. Since training affects not only the type of muscle fibres in the muscles but also their biochemical composition, the type of training that an athlete does could affect the amount of energy produced by this mechanism. But how the structural changes and the generation of force are related has remained a mystery, until now.

Dr Mike Ferenczi, a physical biochemist at the National Institute for Medical Research in London, and his colleagues have used a variety of techniques to study this mechanism, including directing X-rays through single muscle fibres and analysing the patterns of scattered rays that emerge. They have found that the section of the muscle cell responsible for the muscle contracting undergoes a complicated cycle between 20 and 40 times every second. In each cycle, the protein filaments which make up the cell move, a molecule of ATP is broken down, and force is generated. Their latest findings are soon to be published in the American publication, Biophysical Journal.

According to Ferenczi, the energy immediately available to muscles without oxygen lasts for up to eight seconds Ð not quite enough to fuel a 100 metre sprint. There are still questions to be answered, but he believes that once our understanding of the mechanism is complete Ð about the order in which these cyclical changes take place, for example Ð that knowledge will enable athletes to conserve energy more efficiently during a race. More importantly, it could throw light on certain diseases that affect muscles. The by-products of ATP hydrolysis affect not only the skeletal muscles Ð those involved in movement Ð but also muscles such as the heart. ÔTheoretically, one could then design drugs that could alleviate some of the symptoms of heart disease,Õ says Ferenczi.

Sources: National Institute for Medical Research, Mike Ferenczi