StepUp Air is a training solution improving training efficiency by monitoring precisely breathing, the fastest body response to the effort. It combines both hardware – a connected garment measuring breathing and heart rate – and software – a multiplatform app. By measuring breathing, we detect the training zones and body limits in real-time and without using generalizing statistics creating approximations, necessary if only heart rate is measured. Endurance sportspeople get informed when they exercise too hard, and can adapt their training accordingly.