Marathon performance in relation to body fat percentage and training indices in recreational male runners Last year, Pro. Giovanni Tanda has developed a formula on the basis of our numbers from the Marathon in Basel to calculate the marathon period based on characteristic features of the training and body construction for hobbyl racers, see https://pubmed.ncbi.nlm.nih.gov/24379719/. Now Chris Edson, see chrisedson.co.uk based on the formula developed by Prof. Tanda, creates a Web app where you can calculate the probable marathometer, running speed and body fat, the expected marathon time, see http://chrisedson.co.uk/marathon-predictor/index.html