Borussia Dortmund’s second day of training in 2014 started with a lactate threshold test at the Helmut Körnig Indoor Athletics Stadium which involved the taking of blood samples.

The fitness test included six three-minute runs at six different speeds (10, 12, 14, 16, 18, and 20 kilometres per hour), with the players giving their maximum effort at the last level. Blood samples were taken from their ears after each run and during the rest periods by a team of sport scientists.

The specialists will now examine the blood samples and measure them for accumulation of lactic acid. A high lactate concentration is usually a sign that muscles do not produce enough energy after high intensity work which can result in an over-acidification, with the muscles ceasing function as the worst-case scenario. The coaching staff will get the results of the fitness test within in the next couple of days, and based on the findings, each player will get a special fitness plan tailored to their needs.