PT - JOURNAL ARTICLE AU - Sophie É. Collins AU - Devin B. Phillips AU - Andrew R. Brotto AU - Zahrah H. Rampuri AU - Michael K. Stickland TI - Ventilatory efficiency in athletes, asthma and obesity AID - 10.1183/16000617.0206-2020 DP - 2021 Sep 30 TA - European Respiratory Review PG - 200206 VI - 30 IP - 161 4099 - http://err.ersjournals.com/content/30/161/200206.short 4100 - http://err.ersjournals.com/content/30/161/200206.full SO - EUROPEAN RESPIRATORY REVIEW2021 Sep 30; 30 AB - During submaximal exercise, minute ventilation (V′E) increases in proportion to metabolic rate (i.e. carbon dioxide production (V′CO2)) to maintain arterial blood gas homeostasis. The ratio V′E/V′CO2, commonly termed ventilatory efficiency, is a useful tool to evaluate exercise responses in healthy individuals and patients with chronic disease. Emerging research has shown abnormal ventilatory responses to exercise (either elevated or blunted V′E/V′CO2) in some chronic respiratory and cardiovascular conditions. This review will briefly provide an overview of the physiology of ventilatory efficiency, before describing the ventilatory responses to exercise in healthy trained endurance athletes, patients with asthma, and patients with obesity. During submaximal exercise, the V′E/V′CO2 response is generally normal in endurance-trained individuals, patients with asthma and patients with obesity. However, in endurance-trained individuals, asthmatics who demonstrate exercise induced-bronchoconstriction, and morbidly obese individuals, the V′E/V′CO2 can be blunted at maximal exercise, likely because of mechanical ventilatory constraint.The minute ventilation/CO2 production ratio is useful when evaluating exercise responses. This review describes the physiology of the minute ventilation/CO2 production ratio and the ratio response in endurance athletes, asthma and obesity. https://bit.ly/3mFdr81