Indirect calorimetry
An automated respiratory gas analyser and ventilated hood system (Omnical, IDEE, Maastricht, The Netherlands) were used to measure whole-body oxygen consumption and carbon dioxide production of participants in a supine position over a 30-minute period. For the acute effects of clenbuterol, indirect calorimetry data for one participant was excluded due to a technical error. Total energy expenditure and carbohydrate- and fat oxidation was calculated according to Brouwers’ equation