Pushing the limits: does suprahigh-intensity interval training open a new frontier in pulmonary rehabilitation?

Extract Interval training was initially developed in the early 20th century as a method for enhancing athletic performance, based on the premise that it could yield similar or superior physiological adaptations compared to continuous exercise while requiring less total training time. Since then, this exercise modality has evolved into a significant component of rehabilitation programmes for various patient groups. Initially pioneered by the German coach Woldemar Gerschler and the Swedish physiologist Per-Olof Åstrand in the 1930s, the concept of interval training has found its way into pulmonary rehabilitation over the past decades (figure 1). In the late 1980s, interval training started to be applied to cardiac rehabilitation. A study by Meyer et al. in 1990 was one of the earliest reports to show that interval training was more effective in improving exercise capacity and economizing the cardiac function after coronary artery bypass surgery [1]. Around the millennium, researchers began to investigate whether also patients with chronic obstructive pulmonary disease (COPD), who often struggle with continuous exercise due to dyspnoea and muscle fatigue, could tolerate interval training better by introducing appropriately spaced short periods of exercise and rest [2, 3]. This was followed by some research in the early 2000s which looked at the physiological explanations for the benefits of interval training, i.e. lower dynamic hyperinflation and breathlessness compared to continuous exercise [4].