Immediate Effects of an Inverted Body Position on Energy Expenditure and Blood Lactate Removal after Intense Running

We compared the immediate effects of a cool-down strategy including an inverted body position (IBP: continuous 30-s alternations of supine and IBP) after a short period of an intense treadmill run with active (walking) and passive (seated) methods. Fifteen healthy subjects (22 years, 172 cm, 67 kg) completed three cool-down conditions (in a counterbalanced order) followed by a 5-min static stretch on three separate days. Heart rate, energy expenditure, blood lactate concentration, fatigue perception, and circumference of thighs and calves were recorded at pre- and post-run at 0, 5, 10, 20, and 30 min. At 5 min post-run, subjects performing the IBP condition showed (1) a 22% slower heart rate (p < 0.0001, ES = 2.52) and 14% lower energy expenditure (p = 0.01, ES = 0.48) than in the active condition, and (2) a 23% lower blood lactate than in the passive condition (p = 0.001, ES = 0.82). Fatigue perception and circumferences of thighs and calves did not differ between the conditions at any time point (F10,238 < 0.96, p < 0.99 for all tests). IBP appears to produce an effect similar to that of an active cool-down in blood lactate removal with less energy expenditure. This cool-down strategy is recommended for tournament sporting events with short breaks between matches, such as Taekwondo, Judo, and wrestling.