Novice marathon runners will be examined for possible beneficial or harmful cardiac changes by researchers in a new study that hopes to understand the effects of intensive exercise on those not used to it.

Experts at St George's, University of London, will examine 120 marathon participants who will undergo four hours of evaluations before training and after completing their first marathon, including heart scans, an ECG, cardiopulmonary exercise tests and blood tests.

Dr Andrew D'Silva said the study is packed with amazing potential to explore the physiological and structural adaptations of the cardiovascular system in response to high intensity exercise.

"The study focuses on the changes related to intensive exercise and looks at heart muscle structure in detail. Sometimes in athletes the heart can take on an appearance that looks like heart muscle disease, when it is thicker than normal and has a large spongy layer, but is just an adaptive process and goes away once they stop training," he said.

"We hope to better understand why it does this, based on studying the heart and circulation using multiple tests. Through investigating the limits of normal physiological remodelling we aim to better distinguish this from early or mild heart muscle disease."

Baseline tests were conducted on the runners in October last year, with follow up tests planned in May after the marathon.

The principle investigator of the study is Professor Sanjay Sharma from St George's, University of London in collaboration with Professor James C. Moon from Barts Heart Centre and University College London/Queen Mary University of London and is funded by the British Heart Foundation and Cardiac Risk in the Young.

Further information can be found here.