In response to acute endurance-type exercise, triggered from brain, the main physiological adjustments include increased ventilation and pumping function of the heart associated with substantially decreased peripheral vascular resistance in the muscles but largely unchanged or even increased resistance in many other tissues. This facilitates the delivery of oxygen and nutrients to working muscles, which consume high amounts of oxygen and nutrients, especially when exercise intensity increases. These organ-specific responses are discussed in detail in the text. ↑, Increases; ↔, no change in response; ↓, decreases; ↕, may increase or decrease. Published in: Ilkka Heinonen; Kari K. Kalliokoski; Jarna C. Hannukainen; Dirk J. Duncker; Pirjo Nuutila; Juhani Knuuti; Physiology  2014, 29, 421-436. Copyright © 2014 The International Union of Physiological Sciences and The American Physiological Society